Dissertations / Theses on the topic 'Soils Organic fertilizers'

Non-point source pollution of surface waters with phosphorous (P) transported from agricultural soils has emerged as a major environmental issue in the last decade. Regulations limiting P accumulation in surface soils have been established to protect surface water quality. Yet, little information is available on the quantities of P that may leach through soils and the factors influencing P leaching in agricultural soils. One important factor may be the type of fertilizer P applied, since it is known that P solubility varies among fertilizer sources. The purpose of this thesis was to quantify P leaching in soils amended with inorganic and organic fertilizers.<br>In a field study, we found that the fertilizer P source (triple superphosphate, composted cattle manure, or a mixture of the two) did not affect soil test P concentration, the degree of soil P saturation, or P leaching in a sandy-loam soil. The soil test P level in the 0--15-cm depth (146 mg P kg -1) exceeded the critical limit of 66-mg kg-1 established in Quebec, and ortho-P and DOP concentrations in leachates collected from piezometers were generally higher than the provincial water quality standard of 0.03 mg P L-1. If transported from our study site, P leached through this coarse-textured soil could pose a threat to groundwater and surface water quality.<br>These findings were verified in the laboratory with two coarse-textured soils. We found that more NO3-N and DON were leached from soils receiving inorganic N and P fertilizers than composted cattle manure, but the amounts of ortho-P and DOP leached were not affected by fertilizer sources. In coarse-textured soils, the quantities of P leached can be substantial, but depends more on soil characteristics than the fertilizer P source.

Phosphorus (P) is poorly soluble in most soils and, thus, has poor plant uptake efficiency. AVAIL® and Carbond P (CBP) are new fertilizer products shown to increase P use efficiency (PUE) and increase crop yields when grown in P limiting soils. Carbond P has specifically been seen to increases P uptake and crop yields in soils low in P, although effectiveness in regards to soil organic matter is unknown. The objectives of these studies were to determine if the mode of action for these products is related to physiological response, to determine if Carbond P is toxic to plant roots when in direct contact at high rates, and determine the limitations of Carbond P in regards to biomass (yield), P uptake and concentration. We used a hydroponic study to compare CBP to AVAIL in evaluating plant toxicity and plant philological response. AVAIL and CBP were also compared to ammonium polyphosphate (APP) at pH 6 or 8 for hydroponically grown maize (Zea mays L.). Additionally, a glasshouse study evaluated the PUE of CBP with soil in which maize was grown. Soils were moderate or high in organic matter, with 0, 5, 15, 45, or 135 kg P2O5 ha-1 applied as either APP or CBP. Both studies showed that CBP is a suitable PUE enhancing fertilizer. In the greenhouse study, the high organic matter soil revealed that both CBP and APP fertilization resulted in similar increases in biomass yield and P concentration and uptake. However, in the moderate organic matter soil, biomass and total P uptake was significantly greater for CBP than APP at the two lowest P rates of fertilization and significantly higher for APP than CBP at the highest P application rate. In the hydroponic study, neither AVAIL nor CBP had any positive or adverse effects on the plants as compared to APP. These results, coupled with this and previous soil-based greenhouse and field studies with AVAIL and CBP, show that the increase in PUE is not a physiological growth stimulant response, but rather likely the result of impacts on P solubility in the soil. However, the presence of high organic matter in the soil seemed to negate the effects of the organic acid bonded P used in Carbond P. We conclude that CBP, and possibly other organic acid based fertilizers, can assist in furthering agricultural goals, as well as environmental responsibility with these known limits.

Bibliography: leaves 155-169. Studies the effect of nitrogen fertilizer on dry matter production under differing watering regimes. Investigates the accuracy of different crop and soil organic matter models for predicting crop yield, nitrogen uptake and changes in soil organic carbon and nitrogen. Compares the models with data from long-term field experiments on wheat in Australia and sorghum in Ethiopia. Finds that a higher crop yield and better nitrogen and water utilisation can be achieved if addition of nitrogen fertilizer is balanced with soil water.

Replant disease (RD) affects the growth and establishment of young fruit trees in old orchard soils. Organic management strategies are needed as an alternative to chemical controls. Improved phosphorus (P) nutrition to stimulate root growth and improve tree establishment is a well-established strategy; however, only insoluble Rock Phosphate (RP) and Bone Meal (BM) inputs are available to Canadian organic growers. The ability of specific plant growth promoting rhizobacteria to solubilize phosphate may improve P availability and its uptake in young apple trees, replanted into inoculated orchards. In this study, 101 bacteria isolated from the roots of legumes from Saskatchewan soils were screened for P solubilization. Thirty-four of these bacteria were positive for P solubilization as measured by halo diameter production on calcium phosphate medium. Twelve isolates showing the largest halo diameters and three known P solubilizing bacteria (PSB) were compared on three media: calcium phosphate, Pikovskaya (PVK) and PVK with bromophenol blue. All twelve isolates previously identified as Pseudomonas, Rhanella, Serratia and Klebsiella spp. solubilized P on all media, although the halo diameters varied among media. The isolates were tested in liquid culture, where a marked decrease in the pH of the solution was observed and six isolates were identified for further testing in growth pouch assays in the presence of insoluble P. The root growth of apple seedlings inoculated with one of the six bacterial isolates, showed significant increases in total root length, surface area and the number of root tips compared to the control after four weeks of incubation. Three isolates were selected for greenhouse bioassays using five RD-affected soils collected from organic orchards. These isolates were inoculated onto apple trees, alone or in combination with RP or BM. Two field trials were simultaneously conducted in organic apple orchards, using iii the same treatments; however there were no significant effects of the isolate treatments in either set of experiments. Although the strongest P solubilizers did not enhance tree growth in the greenhouse and orchard trials, the in vitro work showed the potential of PSB as a tool to mitigate the impact of RD.

[Truncated abstract] Relationships between the persistence of organic matter added to soil, the dynamics of soil organic carbon (C) and phosphorus (P) were examined in four experiments on lateritic soils of Western Australia. The main objective was to quantify the release of P following organic matter application in soils which have high P adsorbing capacity. Another objective was to confirm that due to its recalcitrant materials, the effect of peat lasted longer in soil than other sources of organic matter in terms of increasing plant-available P fractions. Three experiments were conducted under glasshouse conditions for various lengths of time, with nine- to twelve-month incubations to investigate these hypotheses. As expected, organic matter with lower C:N ratios than peat (lucerne hay) decomposed more rapidly compared with peat, and the most active mineralisation took place within the first three months of incubation. Soil organic-C (extracted by 0.5 M K2SO4) had a significant positive correlation with P extracted with 0.5 M NaHCO pH 8.53. For a higher application rate (120 ton ha-1), peat was better than wheat straw and lucerne hay in increasing extractable bicarbonate-P concentrations in soil, especially at incubation times up to 12 months. Throughout the experiment, peat was associated with a steady increase in all parameters measured. In contrast to peat, nutrient release from lucerne hay and wheat straw was rapid and diminished over time. There was a tendency for organic-C (either in the form of total extractable organic-C or microbial biomass-C) to steadily increase in soil with added peat throughout the experiment. Unlike wheat straw and lucerne hay, extractable organic-C from peat remained in soil and there was less C loss in the form of respiration. Therefore, peat persisted and sequestered C to the soil system for a longer time than the other source of organic matter. Freshly added organic matter was expected to have a greater influence on P transformation from adsorbed forms in lateritic soils than existing soil organic matter. By removing the existing soil organic matter, the effect of freshly applied organic matter can be determine separately from that of the existing soil organic matter for a similar organic-C content. In order to do this, some soil samples were combusted up to 450° C to eliminate inherent soil organic matter. The release of P was greater when organic-C from fresh organic matter was applied to combusted soils than in uncombusted soils that contained the existing soil organic matter. The exception only applied for parameters related to soil micro-organisms such as biomass-C and phosphatase. For such parameters, new soil organic matter did not create conditions favourable for organisms to increase in activity despite the abundance of organic matter available. More non-extractable-P was formed in combusted soils compared to bicarbonate-P and it contributed to more than 50% of total-P. As for the first experiment, peat also showed a constant effect in increasing bicarbonate extractable-P in the soil

Thesis (M.S. in soil science)--Washington State University, August 2009.<br>Title from PDF title page (viewed on Sept. 23, 2009). "Department of Crop and Soil Science." Includes bibliographical references (p. 46-50).

Thesis (PhD)--Stellenbosch University, 2012.<br>ENGLISH ABSTRACT: The use of cowdung as an organic fertilizer in Asian and African agriculture is an ancient practice. This explains its renewed interest, partly due to the financial inability of most farmers to purchase agrochemicals but also the ever increasing need to adopt greener technologies that do not adversely affect soil health, water quality, biodiversity and promote sustained or even increased food production. In this context, many innovative farmers have developed their own novel technologies based on the use of local resources. One such innovation is Sanjeevak (a mix of cow dung, cow urine, water and a handful of sugar); which showed very promising boosting effect on crop productivity. However, very little scientific work has so far been conducted to evaluate its effect as an organic product for soil amendments. The present study was subdivided into three main objectives. (i) To assess the fertilizing value, human health and ecological risk profiles of Sanjeevak; (ii) To screen Sanjeevak for phytohormones content using Salkowski colorimetric method and liquid chromatography – mass spectrometry (LC-MS) (iii) To evaluate Sanjeevak application at various rates on growth parameters and yield of various crops cultivated in glasshouse and field conditions. Sanjeevak was assessed for its micro and macro nutrients contents. The analysis showed the presence of micronutrients such as Mg, Na, Ca and Zn at variable concentrations and phosphorus (P) (0.007%) and potassium (K) (0.063%). However, Sanjeevak content in total nitrogen (TN) (0.11%), and total organic carbon (TOC) (0.71%) was very low; suggesting that it may be a viable source of nutrients only if applied at higher and consistent rates or alternatively by improving its formulation. Also, Sanjeevak was analysed for its microbiological characteristics and level of heavy metals content in comparison to the strictest legislations that regulate the use and application of wastewater sludge to agricultural land in South Africa. The findings showed that heavy metals, which averaged from 0.03±0.01 for Arsenic (As) to 4.74±0.92 mg/kg for Zinc (Zn) and feacal coliform was estimated at 1.2×102 CFU/g dry matter measured were considerably below the threshold (for Arsenic between 40 to 75 mg/kg dry weight; for Zinc between 2800 to 7500 mg/kg dry weight) and faecal coliform bacteria between 1000 to 1×107 CFU/g dry weight for application as a source of soil amendments. Studies investigating the detection and concentration of phytohormones in Sanjeevak were carried out. In using the Salkowski colorimetric method to detect and quantify auxins from Sanjeevak and its composites (cow urine and dung), the results showed the presence of indole-3-acetic acid (IAA) at variable concentrations ranging from 20.38±2.1 ppm in cow urine, 20.1±6.6 ppm in cow dung, Sanjeevak 17.90±1.1 ppm to up to 138.31±12.6 ppm when LTRP was added to Sanjeevak bacterial cultures and by varying parameters such as incubaton time and temperature. Screening of the above mentioned samples for IAA using LC-MS analysis validated earlier findings. Further analysis of these results strongly emphasized the influence of bacteria in Sanjeevak in producing IAA. Trials were carried out both in the glasshouse and the field. In the greenhouse, different Sanjeevak application rates consistently confirmed its root promoting effect on crops such as tomato, cucumber and grapevine and increased wheat yield independent of the nutrients it contains. Marginal increases were recorded between treatments under field conditions; for example compost and compost + Sanjeevak 20.35 and 20.61 t/ha; and 2.46 and 2.60 t/ha compared to the control 11.67 t/ha and 1.29 t/ha respectively for tomato and maize. However, statistical analysis of the results obtained, revealed that there was no difference between treatments (control, compost, Sanjeevak and compost + Sanjeevak) for the same crop tested due to the high coefficient of variation of the data. Therefore, the use of Sanjeevak as an organic source of soil amendments may be considered as a cheaper alternative to effective microorganisms (EM) technology made up of local and natural resources. As observed in the study, it may be best used in combination with a reliable source of plant nutrients.<br>RESUMEE: L'utilisation des excréments de vaches comme engrais organique dans l'agriculture asiatique et africaine est une pratique très ancienne. Ceci explique son intérêt renouvelé, en partie due à aux restrictions monétaires de la plupart des agriculteurs d'acheter des produits agrochimiques, mais aussi la nécessité croissante d'adopter des technologies vertes qui ne nuissent pas à la qualité des sols, des eaux, la biodiversité et qui permettent d’améliorer la production agricole. C’est dans ce contexte que de nombreux paysans ont développé des techniques nouvelles dépendant des ressources naturelles et locales. L’utilisation de Sanjeevak (un mélange d’excréments de vaches, d’urine de vaches, l'eau et du sucre), a démontré sa capacité à accroître la productivité des plantes vivrières. Cependant, très peu de travaux scientifiques ont jusqu'à présent été menée pour étudier ce produit organique. La présente étude a été subdivisée en trois objectifs principaux. (i) Evaluation de la valeur fertilisante, et les profils de risques écologiques et sanitaires de Sanjeevak, (ii) Etudes de détection des phytohormones et leurs concentrations en utilisant une méthode colorimétrique adaptée de celle de Salkowski et la chromatographie liquide - spectrométrie de masse (LC-MS) (iii) Etude des effets de l’utilisation de Sanjeevak a différents taux d’applications sur la croissance et le développement des plants. Sanjeevak a été évaluée pour son contenu en micro et macro nutriments. L'analyse a montré la présence d'oligo-éléments tels que Mg, Na, Ca et Zn à des concentrations variables. De plus, son contenu en éléments majors tels que le phosphore (P) (0.007%), le potassium (K) (0.063%), l’azote (N) (0.11%), et carbone (C) (0.71%) est très faible; suggérant qu'il pourrait être une source viable de nutriments que si elle est appliquée à des taux plus élevés et répétés ou alternativement en améliorant sa formulation. En outre, Sanjeevak a été analysé pour ses caractéristiques microbiologiques et sa concentration en métaux lourds en comparaison a la législation qui réglemente l'utilisation et l'application de déchets liquide d’origines domestiques sur les terres agricoles en Afrique du Sud. Les résultats ont révélé que des métaux lourds et le niveau de coliformes fécaux mesuré était inférieur aux seuils d'application en tant que source d'amendements de sols agricoles. Les études portant sur la détection et la concentration d’hormones végétales ont été effectuées. En utilisant la méthode colorimétrique de Salkowski pour détecter et quantifier les auxines de Sanjeevak, les urines et les excréments de vaches; les résultats ont révélé la présence d'acide indole-3-acétique (AIA) à des concentrations variables dans les urines, les excréments et Sanjeevak. Une autre analyse des échantillons mentionnés ci-dessus pour les AIA en utilisant LC-MS a validé les résultats obtenus au préalable. L’étude détaillée de ces résultats confirme l'influence des micro-organismes dans la production des hormones végétales. Concernant les expériences sous serre, les différents taux d'application de Sanjeevak ont confirmé son effet stimulant à la croissance accélérée des racines des plantes telles que la tomate et les raisins et augmenté le rendement du blé indépendamment des nutriments qu'il contient. L'analyse statistique des résultats obtenus dans des conditions de terrain, a révélé qu'il n'y avait pas de différence entre les traitements (contrôle, compost, compost + Sanjeevak et Sanjeevak) pour la même plantes testées. Par conséquent, l'utilisation de Sanjeevak comme un produit organique qui améliore la qualité des sols et le rendement des cultures vivrières; peu être considéré comme un inoculum contenant des microorganismes constitué de ressources locales et naturelles. Comme l'a observé dans l'étude, il pourrait être mieux utilisé en combinaison avec une source fiable de nutriments végétaux.<br>AFRIKAANSE OPSOMMING: Die gebruik van beesmis as 'n organiese kunsmis in Asië en Afrika is' n eeu-oue landbou praktyk. Dit verklaar die hernude belangstelling, deels vanweë die finansiële onvermoë van meeste boere om landbouchemikalieë aan te koop, maar ook as gevolg van die toenemende behoefte vir groener tegnologie wat nie nadelig is vir grond gesondheid, waterkwaliteit, biodiversiteit en wat volhoubaarheid of selfs verhoogde voedselproduksie bevorder. In hierdie konteks het baie vindingryke boere hul eie nuwe tegnologie, gebaseer op die gebruik van plaaslik verkrygde hulpbronne, ontwikkel. `n Voorbeeld hiervan is Sanjeevak ('n mengsel van beesmis, beesurine, water en die handvol melasse), wat belowende bevorderende effekte op gewas produktiwiteit en grond mikroflora getoon het. Tot dusver was daar egter baie min wetenskaplike werk gedoen om die effek daarvan as 'n organiese produkte vir grond wysigings te evalueer. Hierdie studie was verdeel in vier belangrike doelwitte. (i) Om die bemestingswaarde, menslike gesondheid en ekologiese risiko-profiele van Sanjeevak te evalueer; (ii) Om Sanjeevak vir fitohormone inhoud en vlakke met behulp van 'n kolorimetriese metode afgelei van dié van Salkowski en vloeistofchromatografie – massaspektrometrie (LC-MS) te besigtig; (iii) Glashuis en veld waarneming reaksies met betrekking tot groei parameters en opbrengs van verskeie gewasse na die toediening van Sanjeevak by verskillende tempos; (iv) Laastens, om die effek van die Sanjeevak voorbehandeling op saad ontkieming en voortplanting te toets in vergelyking met die metodes en tegnieke wat gereeld gebruik word. Sanjeevak is geassesseer vir die mikro-en makro voedingstowwe inhoud. Die analise het die teenwoordigheid van mikrovoedingstowwe soos Mg, Na, Ca en Zn by wisselende konsentrasies, asook fosfor (P) (0.007%) en kalium (K) (0.063%), getoon. Sanjeevak inhoud van totale stikstof (TN) (0.11%), en die totale organiese koolstof (TOC) (0.71%) was egter baie laag, wat daarop dui dat dit slegs 'n lewensvatbare bron van voedingstowwe is indien dit by hoër en konsekwente tempos toegedien word of alternatiewelik wanneer formulering daarvan verbeter word. Sanjeevak was ook ontleed vir die mikrobiologiese eienskappe en die vlakke van swaar metale in vergelyking met die streng wetgewing wat die gebruik en toediening van afvalwater slyk op landbougrond in Suid-Afrika reguleer. Die bevindinge het getoon dat swaar metale en fekalieë kolivorm vlakke hier gemeet, aan die drumpel vereistes voldoen vir die toediening as ‘n grondverbeteringsmiddel. Studies wat die opsporing en die konsentrasie van fitohormone in Sanjeevak ondersoek is uitgevoer. In die gebruik van die Salkowski kolorimetrise metode om die ouksiene op te spoor en te kwantifiseer uit Sanjeevak en sy mengsel (beesurine en mis), het die resultate die teenwoordigheid van indol-3-asynsuur (IAA) by wisselende konsentrasies wat wissel van 20 tot 140 ppm in beesurine, beesmis en Sanjeevak getoon. Evaluering van die bogenoemde monsters vir IAA met behulp van LC-MSanalise bevestig vroeër bevindings. Verdere ontleding van hierdie resultate beklemtoon sterk die invloed van Sanjeevak mikrobiota in fitohormone produksie. Proewe is uitgevoer in die glashuis en die veld. In die glashuis eksperimente, is het die verskeie toedieningstempo van Sanjeevak herhalend die wortelbevorderende effekte bevestig op gewasse soos tamaties, komkommer en wingerdstok en dit het opbrengs van koring verhoog, onafhanklik van die voedingstowwe wat dit bevat. Statistiese analise van die resultate verkry onder veldtoestande, het getoon dat daar geen verskil tussen die behandelings (kontrole, kompos, Sanjeevak en kompos + Sanjeevak) was nie, gegee dat dieselfde gewas getoets was. Ten slotte, laboratorium-eksperimente op Sanjeevak as voor-behandeling om die beworteling te verbeter van die wingerdstok (Ramsey) onderstok steggies, het baie belowende resultate getoon in vergelyking met naftaleen asynsuur (NAA) voorbehandeling en die kontrole. Dit beklemtoon die feit dat Sanjeevak 'n alternatief kan wees en wat verdere studie verdien, hoofsaaklik as gevolg van sy lae-koste en omgewingsvriendelike prosedures. Die gebruik van Sanjeevak as 'n organiese grondverbeteringsmiddel vir gewasproduksie en voortplanting kan beskou word as' n goedkoper alternatief tot effektiewe mikro-organisme (EM) tegnologie wat uit plaaslike en natuurlike hulpbronne saamgestel is. Soos waargeneem in die studie, kan dit die beste gebruik word in kombinasie met 'n betroubare bron van plantvoedingstowwe. Dus, moet die gebruik daarvan vir die produksie van gewasse en voortplanting aangemoedig word.

Thesis (Ph.D.)--University of Missouri-Columbia, 2004.<br>(tm) after EM in title is for Trademark symbol. Typescript. Vita. Includes bibliographical references (leaves 120-142). Also available on the Internet.

Onions are highly responsive to endomycorrhizae and improved plant growth is among the benefits associated with this symbiosis, particularly in low phosphorus soils. Although this crop is grown extensively in organic soils, few studies have been conducted on these. Onion plants (Allium cepa L. cv. Norstar) were inoculated with Glomus aggregatum Schenck & Smith, Glomus clarum Nicolson & Schenck, Glomus fasciculatum Gerdemann & Trappe, Glomus intraradix Schenck & Smith and Glomus versiforme (Karst.) Berch and grown in the field and under controlled conditions to evaluate their efficiency in newly reclaimed organic soil of low P fertility. Three species were selected to evaluate the effects of introduced endomycorrhizal fungi effects and P fertilization (equivalent to 0, 24 and 48 kg P ha$ sp{-1}$) on the growth and mineral nutrition of onion plants.<br>Introducing endomycorrhizal fungi in non-sterile soil did not affect the growth and mineral nutrition of onion. Crop maturity was advanced when plants were inoculated, however. Increasing levels of P fertilization did not depress root colonization and onion growth was increased significantly at the highest rate only. These results suggest that higher levels than recommended could be used in this soil. Inoculation in $ gamma$-irradiated (10 kGy, $ sp{60}$Co) soil alleviated excessive Mn absorption by onion plants. Adding P fertilizer depressed growth and root colonization when plants were inoculated with G. clarum and G. intraradix and was related to the low irradiance levels used in this study. G. versiforme appeared to be the most efficient of the introduced species.

Thesis (MSc)--Stellenbosch University, 2015.<br>ENGLISH ABSTRACT: Inorganic fertilizer applications are common practice in commercial agriculture, yet not much is known regarding their interaction with organic matter and soil biota. Much research has been done on the effect of inorganic N on forest litter decomposition, yet very little research has focused on the effect of inorganic fertilizers on crop litters and, to our knowledge, none on composted organic matter. Furthermore none of the research has been done in South Africa. The main aim of this research project was to determine the effect of inorganic fertilizer applications on the decomposition of selected organic matter sources commonly used in South African agriculture and forestry. Two decomposition studies were conducted over a 3-month period, one on composts and the other on plant litters, using a local, sandy soil. In the first experiment a lower quality compost, compost A (C:N ratio, 17.67), and higher quality compost, compost B (C:N ratio, 4.92) was treated with three commercially used fertilizer treatments. Two were typical blends used for vegetable (tomato and cabbage) production: tomato fertilizer (10:2:15) (100 kg N, 20 kg P, 150 kg K per ha) and cabbage fertilizer (5:2:4) (250 kg N, 100 kg P, 200 kg K per ha). The third fertilizer blend, an equivalent mass application of N and P applied at 150 kg of each element per ha, is more commonly used in pastures. In the second experiment, five commonly encountered crop and forestry litters, namely kikuyu grass, lucerne residues, pine needles, sugar cane trash and wheat straw, were selected to represent the labile organic matter sources. The litters were treated with the tomato and cabbage fertilizer applications rates. Both decomposition experiments were conducted under ambient laboratory conditions at field water capacity. Decomposition rates were monitored by determining CO2 emissions, DOC production, β-glucosidase and polyphenol oxidase activity (PPO). At the start and end of decomposition study, loss on ignition was performed to assess the total loss of OM. Based on the results obtained from these two experiments, it was concluded that the addition of high N containing inorganic fertilizers enhanced the decomposition of both composted and labile organic matter. For both compost and plant litters, DOC production was greatly enhanced with the addition of inorganic fertilizers regardless of the organic matter quality. The conclusion can be made that inherent N in organic matter played a role in the response of decomposition to inorganic fertilizer application with organic matter low in inherent N showing greater responses in decomposition changes. For labile organic matter polyphenol and cellulose content also played a role in the responses observed from inorganic fertilizer applications.<br>AFRIKAANSE OPSOMMING: Anorganiese kunsmis toedieningss is algemene praktyk in die kommersiële landbou sektor,maar nog min is bekend oor hul interaksie met organiese materiaal en grond biota. Baie navorsing is reeds oor die uitwerking van anorganiese N op woud en plantasiereste se ontbinding gedoen. Baie min navorsing het gefokus op die uitwerking van anorganiese kunsmis op die gewasreste en tot ons kennis, is daar geen navorsing gedoen op die invloed van anorganiese kunsmis op gekomposteer organiese material nie. Verder is geeneen van die navorsing studies is in Suid-Afrika gedoen nie. Die hoofdoel van hierdie navorsingsprojek was om die effek van anorganiese kunsmis toedienings op die ontbinding van geselekteerde organiese materiaal bronne, wat algemeen gebruik word in die Suid-Afrikaanse landbou en bosbou, te bepaal. Twee ontbinding studies is gedoen oor 'n 3-maande-tydperk, een op kompos en die ander op die plantreste, met die gebruik van 'n plaaslike, sanderige grond. In die eerste eksperiment is ‘n laer gehalte kompos, kompos A (C: N verhouding, 17.67), en 'n hoër gehalte kompos, kompos B (C: N verhouding, 4.92) met drie kommersieel anorganiese bemesting behandelings behandel. Twee was tipiese versnitte gebruik vir die groente (tamatie en kool) produksie: tamatie kunsmis (10: 2:15) (100 kg N, 20 kg P, 150 kg K per ha) en kool kunsmis (5: 2: 4) (250 kg N, 100 kg P, 200 kg K per ha). Die derde kunsmis versnit was 'n ekwivalente massa toepassing van N en P van 150 kg van elke element per ha, wat meer algemeen gebruik word in weiding. In die tweede eksperiment was vyf algemeen gewas en bosbou reste, naamlik kikoejoegras, lusern reste, dennenaalde, suikerriet reste en koring strooi, gekies om die labiele organiese materiaal bronne te verteenwoordig. Die reste is met die tamatie en kool kunsmis toedienings behandel. Beide ontbinding eksperimente is uitgevoer onder normale laboratorium toestande by veldwaterkapasiteit. Ontbinding tempo is deur die bepaling van die CO2-vrystellings, opgelosde organiese koolstof (OOK) produksie, β-glukosidase en polifenol oksidase aktiwiteit (PPO) gemonitor. Aan die begin en einde van ontbinding studie, is verlies op ontbranding uitgevoer om die totale verlies van OM te evalueer. Gebaseer op die resultate van hierdie twee eksperimente, was die gevolgtrekking dat die toevoeging van hoë N bevattende anorganiese bemestingstowwe die ontbinding van beide komposte en plant reste verhoog. Vir beide kompos en plantreste word OOK produksie verhoog met die toevoeging van anorganiese bemesting, ongeag van die organiese materiaal gehalte. Die gevolgtrekking kan gemaak word dat die inherente N in organiese materiaal 'n rol gespeel het in die reaksie van ontbinding op anorganiese bemesting toedienings met die grootste reaksie in organiese material laag in inherente N. Vir labiele organiese material het polifenol en sellulose inhoud ook 'n rol gespeel in die reaksie waargeneeming op anorganiese bemesting.

Entre os fitopatógenos habitantes do solo, o Pythium sp. é um dos mais agressivos e de difícil controle e acomete diversas culturas comerciais. Na cultura do pepino (Cucumis sativus L.) causa podridão de colo e conseqüente tombamento de plântulas. O controle deste fitopatógeno é baseado em alternativas culturais, por o tratamento químico de sementes não ser efetivo. A adição de compostos orgânicos promove alterações químicas, físicas e biológicas no solo e alterações nutricionais nas plantas. O chorume de suínos apresenta-se como uma alternativa de controle deste fitopatógeno, devido a sua disponibilidade e ao seu potencial nutricional. No entanto, o pH do solo influencia na liberação de diferentes compostos pelo chorume de suínos e, consequentemente, na sua ação sobre os patógenos. Para o gênero Pythium, não existem relatos de utilização de chorume de suínos como alternativa de controle aplicado em diferentes níveis de pH do solo. Este trabalho avaliou o efeito da aplicação de chorume de suínos em solo com diferentes níveis de pH, sobre o controle da doença, sobre o desenvolvimento do fitopatógeno e sua influência nas características químicas e biológicas do solo. Três diferentes situações foram testadas, sendo em todas mantidas a aplicação de 0, 5, 10 e 15% de chorume. Em experimentos com arranjo inteiramente casualizado. Em placas de Petry, avaliou-se a aplicação dos volumes de chorume de suínos em solo com pH 4,8, 6,3 e 8,4, com 1, 2 e 3 dias de incubação sobre o crescimento micelial do Pythium sp. No solo com pH 8,4 o crescimento das colônias foi superior em todos os períodos testados, e em solo pH 4,8 e 6,3 com até dois dias de desenvolvimento, as colônias tiveram um crescimento micelial inibido. Em experimentos inteiramente casualizado, com incubação hermética dos mesmos volumes de chorume de suínos, por quatro dias em solo com pH 4,8, 6,3 e 8,4, obteve-se menor índice de tombamento de plantas no solo pH 4,8. Em outra situação, avaliou-se em experimentos com blocos ao acaso o efeito de diferentes volumes de chorume de suínos sobre o tombamento de plantas de pepino em vasos. A aplicação deste em solo com dois diferentes níveis de pH (pH 4,8 e 6,3), revelou menor número de plantas de pepino tombadas no solo com pH 4,8. Em todas as situações o efeito fungitóxico dos ácidos graxos voláteis, liberados pelo chorume de suínos, quando aplicado em solo com maior nível de acidez, foi apontado como a principal causa da obtenção destes resultados.<br>Among the soilborne plant pathogens, the Pythium sp. is one of the most aggressive and difficult to control and affects several crops. In the culture of cucumber (Cucumis sativus L.) causes collar rot and subsequent damping-off. Control of this pathogen is based on cultural alternatives for the chemical treatment of seed not be effective. The addition of organic compounds promotes chemical changes in soil physical and biological and nutritional changes in plants. The swine manure is presented as an alternative to control this pathogen due to its availability and its nutritional potential. However, soil pH influences the release of different compounds by swine manure and consequently in its action on pathogens. For the genus Pythium, there are no reports of use of swine manure as an alternative control applied at different levels of soil pH. This study evaluated the effect of swine manure in soil with different pH levels on disease control on the development of the pathogen and its influence on chemical and biological soil. Three different situations were tested, and all maintained in the application of 0, 5, 10 and 15% manure. In experiments with randomized arrangement. In Petry plates, evaluated the implementation of the volumes of swine manure in soil with pH 4.8, 6.3 and 8.4, 1, 2 and 3 days of incubation on the mycelial growth of Pythium sp. In soil with pH 8.4 the growth of colonies was higher in all periods tested, and soil pH 4.8 and 6.3 with up to two days of development, the colonies had inhibited growth. In randomized experiments, with incubation hermetic same volumes of swine manure, for four days in soil with pH 4.8, 6.3 and 8.4, we obtained a smaller rate of damping of plants in soil pH 4.8. In another situation, it was evaluated in experiments with randomized block the effect of different amounts of swine manure on the registration of cucumber plants in pots. The application of soil with two different pH levels (pH 4.8 and 6.3) revealed a lower number of cucumber plants having fallen to the ground with pH 4.8. In all cases, the antifungal effect of volatile fatty acids, released by swine manure, when applied to soil with higher acidity level, he was appointed as the main cause of getting these results.

Master of Science<br>Department of Horticulture, Forestry, and Recreation Resources<br>Rhonda R. Janke<br>Petiole sap nitrate-nitrogen (NO3-N) analysis with handheld meters is a valuable tool in applying in-season nitrogen (N) for many crops. Sufficiency levels have been determined for several leafy green crops, including lettuce (Lactuca sativa L.) and cabbage (Brassica oleracea L.), but not for pac choi (Brassica rapa L.). The response of pac choi to different fertilizer rates and sources [conventional and organic] has established optimal soluble N application rates and Cardy meter sufficiency ranges. Greenhouse experiments were conducted during summer and fall of 2008 in Manhattan, KS. Conventional soluble fertilizer was formulated from inorganic salts with a 4 NO3-N: 1 ammonium ratio. Phosphorus was held at 1.72mM and K at 0.83mM for all treatment levels. The organic soluble fertilizer, fish hydrolyzate (2N:1.72P:0.83K), was diluted to provide the same N levels as with conventional treatments. Both fertilizers were applied at rates of 0, 32, 75, 150, 225, 300, and 450 mg. L-1. Seedlings were transplanted and fertilizer application began at 18 days. Plants were harvested at seven weeks (five weeks post transplanting) after receiving 15 fertilizer applications during production. Samples of the most recently matured leaves were harvested weekly and analyzed for petiole sap NO3-N and leaf blade total N concentration. Leaf count, leaf length, and chlorophyll content were also measured weekly. Fresh and dry weights were determined on whole shoots and roots. Optimum yield was achieved at the 150 mg. L-1 fertility rate with both conventional and organic fertilizers. Field and high tunnel experiments were conducted during fall 2008 to validate the sufficiency ranges obtained from the greenhouse studies. Based on field and high tunnel results, sufficiency levels of NO3-N for pac choi petiole sap during weeks 2 to 3 of production were 800-1500 mg. L-1, and then dropped to 600-1000 mg. L-1 during weeks 4 through harvest for both conventional and organic fertilizers sources. These ranges could vary based on the variety of the crop, the fertility of soil, and certain environmental factors such as photoperiod, light intensity. However, we found that petiole sap nitrate always increased to the point associated with the maximum biomass, followed by a plateau where sap nitrate remained constant. This characteristic of the Cardy meter can provide the growers with a practical methodology to generate their standard curves under specific conditions to guide in-season N applications. Total N in leaf tissue showed fewer fertilizer rate effects than petiole sap NO3-N. Chlorophyll content was not useful in evaluating pac choi N status.

Dans le contexte environnemental actuel il est nécessaire d’optimiser l’utilisation des ressources pour réduire les déchets et les émissions de gaz à effet de serre (GES). L’utilisation de ressources renouvelables et le recyclage sont au cœur du modèle d’économie circulaire, selon lequel le déchet est une ressource mobilisable, transformable, réutilisable et par conséquent non limitée. En agriculture, le cercle vertueux de l’économie circulaire peut être mis en place à travers le recyclage des matières organiques en tant que fertilisants et l’adoption d’une approche agroécologique qui privilégie les services écosystémiques pour lutter contre les nuisibles, protéger le sol et augmenter ses stocks de carbone, dont un des exemples est le paillage. Dans la culture de canne à sucre, la paille laissée à la surface du sol, est aussi de plus en plus convoitée par les industriels pour la production d’agrocarburant de seconde génération. L’émergence d’une telle concurrence d’usage de la biomasse et les enjeux environnementaux sous-jacents imposent d’évaluer à la fois les avantages et les inconvénients agronomiques et environnementaux du recyclage conjoint du paillis de canne à sucre et des fertilisants organiques. Les objectifs de ce travail sont donc i) de comparer l’effet des fertilisants de qualité physicochimique contrastée, sur la décomposition d’un paillis de canne à sucre, et ii) d’évaluer les potentialités d’émission de GES des mélanges paillis-fertilisant en fonction de la quantité de paille laissée et de la qualité des fertilisants apportés. La stratégie de recherche adoptée visait dans un premier temps à détecter des interactions carbone/azote lors du recyclage conjoint de la paille et des fertilisants organiques. Nous avons ainsi testé la prédictibilité des dynamiques de minéralisation du C et du N des matières organiques seules, ou en mélange (paille/fertilisant) en laboratoire, par un modèle additif simple et un modèle mécaniste de transformation du carbone et de l’azote dans le sol – CANTIS. Nos résultats ont montré que les deux modèles ont surestimé la minéralisation du C et n’ont pas prédit correctement la minéralisation du N des deux mélanges. Cette interaction antagoniste pour les mélanges a pu être corrigée par l’application d’un facteur de contact dans CANTIS, qui reflète la diminution de la biodisponibilité du C et du N, due à des hétérogénéités de distribution à une échelle fine du sol. Dans un deuxième temps, nous avons effectué des essais au champ (en condition réelles) pour suivre à la fois la décomposition de la paille de canne à sucre en mélange avec des fertilisants organiques et les émissions de GES. La quantité de paille décomposée a été proportionnelle à la quantité initiale laissée et n’a été affectée ni par la quantité de paille initiale, ni par le type de fertilisant apporté. Cette proportionnalité est transposable aux potentialités de stockage de carbone dans le sol et devrait être considérée lors de la mise en place de programmes de séquestration de carbone dans le sol ou lors de l’exportation de la paille pour une utilisation par ailleurs. Le type de fertilisant a un rôle clef sur les émissions de GES à court terme après la fertilisation. Les flux d’émissions moyens de CO2 et de N2O les plus élevés ont été obtenus en appliquant du lisier de porc, qui a une forte teneur en eau et est riche en N minéral. A l’inverse, les cinétiques des émissions de GES des fertilisants solides ont été régis par des facteurs environnementaux, dont certains pourraient être contrôlés, tels que l'apport en eau ou la quantité de fertilisant. L’utilisation de fertilisants organiques est bénéfique lorsqu’ils sont riches en N organique et pauvres en teneur en eau, comme la boue de station d’épuration sèche, mais la minéralisation de l’azote dans ce cas est progressive et nécessite l’élaboration de plans d’épandage spécifiques pour répondre aux besoins des cultures<br>In the current environmental context, it is crucial to optimize the use of resources to reduce waste and greenhouse gas (GHG) emissions. Renewable resources use and recycling lies at the heart of the circular economy model, in which a waste is a mobilizable, transformable, reusable and therefore renewable resource. In agriculture, the “virtuous circle” of circular economy can be achieved through the recycling of organic wastes as fertilizer and the adoption of an agroecological approach that favors ecosystem services for pest control, soil protection and carbon stocks increase, one of the examples of which is mulching. In sugarcane cropping systems straw left on the soil surface is also increasingly coveted by industrial sector to produce second-generation agrofuels. The emerging competition for biomass use and the underlying environmental issues make it necessary to assess both, the agronomic and the environmental advantages and disadvantages of joint recycling of sugarcane mulch and organic fertilizers. Therefore, the objectives of this work are i) to compare the effect of fertilizers of contrasting physicochemical quality, on the decomposition of a sugarcane mulch, and ii) to evaluate the potential of GHG emissions from mulch-fertilizer mixtures, according to the quantity of straw left and the quality of the fertilizers applied. The research strategy adopted in a first step aimed to detect carbon/nitrogen interactions during the combined recycling of straw and organic fertilizers. We have thus tested the predictability of the mineralization dynamics of C and N of the organic materials alone, or in mixture (straw/fertilizer) in the laboratory, by a simple additive model, and a mechanistic model of carbon and nitrogen transformation in the soil - CANTIS. Our results showed that both models overestimated the C mineralization and did not correctly predict the N mineralization of the mixtures. This antagonistic interaction for the mixtures was corrected by the application of a contact factor in CANTIS, which reflects the bioavailability decrease of C and N, due to distribution heterogeneities at a fine scale within the soil. In a second step, we conducted field trials (under real conditions) to measure both the decomposition of sugarcane straw mixed with organic fertilizers and GHG emissions. The amount of straw decomposed was proportional to the initial amount left and was affected neither by the amount of straw nor the type of fertilizer provided. This proportionality is transposable to the potential for carbon sequestration in the soil and should be considered when setting up carbon sequestration or when exporting the straw for alternative use. The type of fertilizer plays a key role in GHG emissions in the short term after fertilization. The highest average CO2 and N2O emission fluxes were obtained by applying pig slurry, which has a high water content and is rich in mineral N. Conversely, the kinetics of GHG emissions from solid fertilizers have been governed by environmental factors, some of which could be controlled, such as water intake or fertilizer quantity application. The use of organic fertilizers is beneficial when they are rich in organic N and poor in water content, such as dry sewage sludge, but the mineralization of nitrogen in this case is gradual and requires elaboration of a specific application strategies to meet crop needs. A better integration of the interactions between the different N and C sources should be considered, in order to develop modeling as a precise tool for the management of an agroecosystem

Thesis (M.S.)--University of North Carolina at Chapel Hill, 2007.<br>Title from electronic title page (viewed Apr. 25, 2008). "... in partial fulfillment of the requirements for the degree of Master of Science in the Department of Environmental Science and Engineering." Discipline: Environmental Sciences and Engineering; Department/School: Public Health.

Darbo tikslas – nustatyti fosforo trąšų įtaką dirvožemio elektrocheminių parametrų kaitai bei miežių grūdų kokybės parametrams. Darbo uždaviniai: o nustatyti sertifikuotų ekologiškų fosoforo trąšų fosforitmilčių įtaką dirvožemio elektrocheminėms savybėms; o nustatyti sertifikuotų fosforo trąšų įtaką žemės ūkio augalų grūdų elektrocheminėms savybėms. Darbo objektas – Lietuvos žemės ūkio universiteto Agroekologijos centro ekologinės gamybos ūkio dirvožemis bei jame auginti vasariniai miežiai. Darbo rezultatai. Lietuvos žemės ūkio universiteto Agroekologijos centro ekologinės gamybos ūkyje atlikus sertifikuotų fosforo trąšų įtakos dirvožemio elektrocheminėms savybėms tyrimus, nustatyta, kad patręšus P60 fosforitmičių norma esminiai padidėjo dirvožemio pH rodiklio reikšmė, lyginant su netręštu dirvožemiu bei tręšimu P90 ir P120 normomis. Tiriant dirvožemio savitojo elektrinio laidžio reikšmes prieš tręšimą fosforo trąšomis pavasarį ir po vasarinių miežių derliaus nuėmimo, nustatyta, kad dirvožemio savitojo elektrinio laidžio reikšmės sumažėjo esminiai. Ištyrus dirvožemio savitąjį elektrinį laidį rudenį po tręšimo fosforo trąšomis, nustatyta, kad dirvožemio savitasis elektrinis laidis esminiai padidėjo, lyginant su dirvožemio ėminiais, paimtais po vasarinių miežių nupjovimo, bet negauta esminių skirtumų, lyginant su dirvožemio ėminiais paimtais pavasarį prieš vasarinių miežių tręšimą. Patręšus didžiausia tirta P120 fosforo trąšų norma, esminiai padidėjo dirvožemio redokso... [toliau žr. visą tekstą]<br>The thesis aims at defining the effect of phosphatic fertilizers on the change of electrochemical parameters of the soil and the quality parameters of barleycorn. The goals of the thesis are as follows: • determination of the effect of bone meal as a certified organic phosphatic fertilizer on the electrochemical parameters of the soil. • determination of the effect of certified phosphatic fertilizers on the electrochemical parameters of the crop grain. The soil of the organic farm of the Agro-ecological Centre of the Lithuanian University of Agriculture and spring barley grown therein constitute fall within the scope of the thesis. Findings. Research of the effect of certified phosphatic fertilizers on the electrochemical parameters of the soil in the organic farm of the Agro-ecological Centre of the Lithuanian University of Agriculture shows that application of the standard P60 bone meal resulted in a considerable increase of the pH value of the soil, as compared to unfertilized soil or use of the standard P90 and P120. The analysis of the values of soil conductivity before application of phosphatic fertilizers in spring and after reaping of spring barley reveals that the values of soil conductivity decreased to a remarkable extent. After testing of soil conductivity in autumn after use of phosphatic fertilizers it was established that soil conductivity, as compared to the soil samples taken after reaping of spring barley, considerably increased, however, testing shows no... [to full text]

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico<br>Desde que o homem descobriu na agricultura uma forma de obter alimentos, a natureza passou a ser modificada. AlteraÃÃes foram causadas no ecossistema e com elas vieram as perdas na qualidade do solo. Com isso, sentiu-se a necessidade da implantaÃÃo de sistemas que preconizam pela conservaÃÃo do solo e, dessa forma, os resÃduos que antes eram queimados ou retirados da Ãrea agrÃcola comeÃam a ser deixados na superfÃcie do solo com o intuito de protegÃ-lo e promover melhorias na sua qualidade. Nesse contexto, a aplicaÃÃo de resÃduo orgÃnico no solo, como o bagaÃo de caju, pode trazer benefÃcios à qualidade fÃsica do mesmo. Diante do exposto, o objetivo da pesquisa foi avaliar o efeito da aplicaÃÃo de resÃduo de caju sobre a qualidade fÃsica do solo por meio de indicadores. Foram coletadas amostras de solo com estrutura preservada e nÃo preservada. As anÃlises foram determinadas em campo (infiltraÃÃo e condutividade hidrÃulica) e em laboratÃrio (Ãndice S e permeabilidade do solo ao ar). O delineamento empregado foi o de blocos ao acaso, composto por 5 tratamentos (cinco nÃveis de aplicaÃÃo â 0, 1, 2, 3, 4, que corresponde, respectivamente a: testemunha, 16, 32, 48, 64 t ha-1 de resÃduo orgÃnico) e quatro blocos. Para a anÃlise estatÃstica, verificou-se a normalidade dos dados a partir do teste de Kolmogorov-Smirnov e, em seguida, realizou-se a anÃlise de variÃncia e o teste Tukey a 5 % de probabilidade. Os valores condutividade hidrÃulica em solo saturado (K0) estiveram na faixa que variou de alta a muito alta, reduzindo a possibilidade de escoamento superficial. O resÃduo nÃo influenciou na retenÃÃo de Ãgua no solo, mesmo em doses elevadas. O Ãndice S mostrou valores acima dos considerados pela literatura (>0,035), sugerindo um bom indicador na qualidade estrutural do solo em estudo. A permeabilidade do solo ao ar (Kar) tambÃm demonstrou valores muito acima daquele considerado crÃtico (> 1Âm2), nÃo sendo, portanto, restritivo ao crescimento das plantas. à possÃvel afirmar que os resultados elevados K0, Ãndice S e Kar estiveram intimamente relacionados com a macroporosidade, caracterÃstica inerente ao solo utilizado nessa pesquisa. As doses crescentes de resÃduo de caju nÃo influenciaram significativamente nos resultados supracitados.<br>Since man discovered agriculture as a way to get food, nature has been modified. Changes were caused in the ecosystem and with them came the losses in soil quality. Therefore, it was presumed the need to implement systems that imply on the conservation of soil and thus the plant residues that were burned or removed from the agricultural area started to be left on the soil surface in order to protect the soil and to promote improvements in their quality. In this context, the application of plant residues on the soil, such as cashew residues, can bring benefits to physical quality of the soil. Given this, the present research objective was to evaluate the effect of cashew residue on soil physical quality measured through indicators. Samples were collected from both undisturbed not preserved soil. The analyzes were determined in the field (infiltration and hydraulic conductivity) and in the laboratory (index S and soil air permeability). The experimental design was randomized blocks, consisting of 5 treatments (five application rates: 0, 1, 2, 3, 4, which correspond, respectively, to: control, 16, 32, 48, 64 t ha-1 organic waste) and four blocks. For statistical analysis, it was verified the normality of data from the Kolmogorov-Smirnov and, then, followed by the analysis of variance and Tukey test at 5% probability. The values for saturated hydraulic conductivity (K0) was found to be in the range varying from high to very high, with reducing the possibility of superficial runoff. The residue did not affect the soil water content, even at high rate applications. The S index showed values above those shown in the literature (> 0.035), suggesting a good indicator of the soil quality under study. The soil air permeability (Kar) also had values above that considered critical (> 1&#956;m2), being, therefore, limiting to plant growth. It can be argued that the high results K0, S and Kar were closely related to macroporosity, inherent characteristic of the soil used in this research. Increasing application rates of cashew residues did not significantly influence the above results.

Submitted by Katiane Souza (katyane.souza@gmail.com) on 2016-04-05T23:27:02Z No. of bitstreams: 1 arquivototal.pdf: 754987 bytes, checksum: 9c6daa9c670f621928da7b0d4797c1e4 (MD5)<br>Made available in DSpace on 2016-04-05T23:27:02Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 754987 bytes, checksum: 9c6daa9c670f621928da7b0d4797c1e4 (MD5) Previous issue date: 2006-02-24<br>Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq<br>Green bell pepper (Capsicum annuum L.) is a tropical plant of the Solanaceae family with origin in Latin America. In recent years, organic cropping systems using liquid biofertilizers have had an important impulse in Brazil. The objectives of this study were to evaluate green bell pepper yield, soil fertility changes and plant nutritional status in response to different types of liquid biofertilizers applied to the soil. The experiment was carried out at Macaquinhos Farm, in the municipality of Remígio-PB, in a randomized block design with three replicates. Treatments were distributed on a 2 × 5 factorial arrangement, regarding two types of cattle manure biofertilizer (raw and agrobio) and five doses of biofertilizers based on calcium rates (0; 0,65; 1,30; 1,95 and 2,60 g pit-1). Each plot was composed by 21 pits spaced by 1 × 0,50 m, with two plants. The use of biofertilizers in the doses tested in this study had no significant effect on green bell pepper growth as measured by height and stem diameter. For average fruit mass and average number of fruits per pit, there was a significant response green bell pepper plants to the calcium doses, regardless the type of biofertilizer. A statistical superiority of agrobio biofertilizer over raw biofertilizer was detected for the levels of sulfur, boron, iron and zinc in plant leaf tissues. Regarding soil fertility components, there was no difference between the two biofertilizer types, but pH values and phosphorus and potassium levels increased significantly.<br>O pimentão (Capsicum annuum L.) é uma planta pertencente a família das solanáceas, de clima tropical e de origem latino americana. Nos últimos anos, sistemas de cultivo orgânico com a utilização de biofertilizantes líquidos tiveram um grande impulso no Brasil. Os objetivos deste estudo foram avaliar a produtividade do pimentão, as mudanças na fertilidade do solo e o estado nutricional das plantas em resposta a diferentes biofertilizantes líquidos aplicados no solo. O experimento foi realizado no Sítio Macaquinhos, localizado no município de Remígio-PB, em delineamento em blocos ao acaso, em triplicata. Os tratamentos foram distribuídos em esquema fatorial 2 × 5, referente a dois tipos de biofertilizantes de esterco bovino (puro e agrobio) e cinco doses definidas a partir de níveis de cálcio (0; 0,65; 1,30; 1,95; 2,60). Cada parcela constou de 21 covas em espaçamento de 1 × 0,50 m, com 2 plantas cada. Nas doses em que foram testados, os biofertilizantes puro e agrobio não afetaram significativamente o crescimento em altura e diâmetro caulinar do pimentão. Quanto ao peso médio e número médio de frutos por cova, houve resposta significativa das plantas de pimentão as doses de cálcio, independentes do tipo de biofertilizante. A superioridade estatística do biofertilizante agrobio sobre o biofertilizante puro foi verificada para os teores foliares de enxofre, boro, ferro e zinco. Os biofertilizantes não diferiram entre si em relação aos componentes da fertilidade do solo, mas elevaram os valores do pH, fósforo e potássio.

Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2018-09-24T19:29:23Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Anderson_Rosa_2018.pdf: 394581 bytes, checksum: 96f973e7cdd32576a855f0e1dfd0f946 (MD5)<br>Made available in DSpace on 2018-09-24T19:29:23Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Anderson_Rosa_2018.pdf: 394581 bytes, checksum: 96f973e7cdd32576a855f0e1dfd0f946 (MD5) Previous issue date: 2018-03-27<br>The production of animal protein in confined space is an activity that has been highlighting in the western region of Paraná, due to the increase in the demand for food. The use of organic wastes as fertilizers is a profitable practice for the rural producer, but the application of high amounts and in a continuous way can cause accumulation of nutrients, biological agents as well as oils and greases that can cause environmental problems. The objective of this work was to evaluate the accumulation of phosphorus, potassium, copper, iron, manganese, zinc, oils and greases in Oxisols fertilized with swine manure. The experiments were installed in two municipalities in the state of Paraná. In Santa Tereza do Oeste it started in 2015. The treatments were three doses of liquid swine manure, on average, 50; 100 and 150 m³ ha-1 year-1 one control and one treatment with chemical fertilization using NPK formulated. In Palotina it was started in 1997 and the treatments were three doses of liquid swine manure, 30, 60 and 120 m³ ha-1 and one control. The experimental design was a randomized block with four replications in plots of 50 m2. Soil sampling was performed before planting the 2017/2018 crop in each plot at 0-5 and 5-10 cm depths. Contents of P, K, Cu, Fe, Mn and Zn were evaluated by the Mehlich-1 method and the oil and grease content by the Soxhlet lipid extractor with organic solvent hexane. The data were submitted to analysis of variance and the averages were compared by the Tukey test at 5% probability. The application of swine manure influenced the levels of phosphorus, potassium, copper, manganese, zinc, oils and greases of the soil in the areas sampled, with a higher concentration observed in the 0-5 cm depth layer. The doses of the swine manire contributed significantly to the increase of phosphorus, potassium, copper, zinc, and oils and greases concentrations in the soil.<br>A produção de proteína animal em espaço confinado é uma atividade que vem se destacando na região Oeste do Paraná, devido ao aumento da demanda por alimentos. O uso de resíduos orgânicos como fertilizantes é uma opção rentável ao produtor rural, porém a aplicação de quantidades elevadas e de maneira contínua pode ocasionar acúmulo de nutrientes e também óleos e graxas, podendo causar problemas ambientais. O objetivo desse trabalho foi avaliar o acúmulo de fósforo, potássio, cobre, ferro, manganês, zinco, óleos e graxas em Latossolos adubados com dejeto de suínos. Os experimentos foram instalados em dois municípios do estado do Paraná. Em Santa Tereza do Oeste, iniciou-se em 2015. Os tratamentos foram três doses de dejeto líquido de suínos: 50, 100 e 150 m³ ha-1 ano-1 (em média), uma testemunha e um tratamento com adubação química utilizando-se formulado NPK. Em Palotina, iniciou-se em 1997 e os tratamentos foram três doses de dejeto líquido de suínos: 30, 60 e 120 m³ ha-1 ano-1 e uma testemunha (sem aplicação). O delineamento experimental foi o de blocos casualizados com quatro repetições, em parcelas de 50 m2. A amostragem do solo foi realizada antes do plantio da safra 2017/2018 em cada parcela, nas camadas de 0-5 e 5-10 cm. Teores de P, K, Cu, Fe, Mn e Zn foram avaliados pelo método Mehlich-1 e os teores de óleos e graxas por meio do extrator de lipídios Soxhlet, com solvente orgânico hexano. Os dados foram submetidos à análise de variância e o as médias foram comparadas pelo teste de Tukey a 5 % de probabilidade. A aplicação de dejeto líquido de suínos influenciou os teores de fósforo, potássio, cobre, manganês, zinco, óleos e graxas do solo nas áreas amostradas, com concentração maior observada na camada de 0 - 5 cm de profundidade. As doses do dejeto líquido de suínos contribuíram significativamente para o aumento das concentrações de fósforo, potássio, cobre, zinco e óleos e graxas no solo, sendo que o maior volume de dejeto líquido de suínos aplicado proporcionou maior concentração desses elementos no solo.

Os solos tropicais altamente intemperizados apresentam elevada capacidade de adsorção de fósforo. Vários fatores podem influenciar a adsorção de P nestes solos, dentre eles destaca-se o teor de matéria orgânica. Os mecanismos envolvidos neste processo estão relacionados à liberação de ácidos orgânicos oriundos da decomposição da matéria orgânica, podendo ser de baixa massa molecular tais como, malato, oxalato ou citrato, ou de elevada massa molecular como ácidos húmicos e fúlvicos, que atuam na complexação do Fe ou Al em solução ou na superfície dos colóides, que por meio de troca de ligantes reduz assim a adsorção de P. O presente trabalho constou de quatro estudos, ambos realizados em casa-de-vegetação do Departamento de Ciência do Solo da ESALQ/USP, tendo como objetivos: (i) verificar o efeito da adição de ácidos orgânicos e fontes de substâncias húmicas, na disponibilidade de P em solos com diferentes capacidades de adsorção. Os tratamentos compreenderam 2 tipos de solo (Latossolo vermelho amarelo - LVA e LV), 2 fontes de P (Fosfato monocálcico - FMC p.a. e Fosfato natural reativo de Arad - FNR), 2 fontes de ácidos orgânicos de baixa massa molecular - AOBM (ácido cítrico - AC e ácido oxálico - AO), 2 fontes de substâncias húmicas (condicionador orgânico de solo - CO e turfa -TF)). As doses de AOBM foram de 0, 2, 4 e 8 mmol kg-1 e CO de 0, 150, 300, 600 L ha-1 e de TF 0, 20, 40, e 80 t ha-1; (ii) avaliar a eficiência agronômica de fontes de fósforo com solubilidade variável em água, com e sem adição de matéria orgânica. Os tratamentos constaram de 2 tipos de solo (LVA e LV), 2 fontes de P (Superfosfato triplo - SFT e Fosfato natural reativo - FNR), 3 doses de P (0, 50 e 100 mg kg-1 de P) e 3 doses de turfa - TF, correspondendo a 0, 25 e 50 t ha-1; (iii) avaliar o efeito da adição de fontes de substâncias húmicas na eficiência agronômica das fontes de P. Os tratamentos constaram de 2 solos (LVA e LV), 2 fontes de P (SFT e FNR) e 2 fontes de substâncias húmicas - FSH (CO e TF) e (iv) avaliar o efeito da adição e forma de aplicação de ácido cítrico na eficiência agronômica das fontes de P. O ácido cítrico (AC) foi adicionado nas doses de 0, 4 e 8 mmol kg-1 de AC, sendo as formas de aplicação avaliadas foram: (a) plantio (a dose completa de AC foi aplicada no plantio); (b) reposição = plantio + reposição (a dose completa de AC foi aplicada no plantio, sendo feito a reposição aos 7, 14, 21 e 28 dias de AC correspondendo a 50 % das doses iniciais; (c) parcelado (as doses de AC foram parceladas em 4 vezes). Os resultados obtidos permitem concluir que: a adição de ácidos orgânicos de baixa massa molecular e fontes de substâncias húmicas aumentou a disponibilidade de P, com maiores efeitos nos solos de baixa capacidade de adsorção de fósforo. O aumento da eficiência agronômica relativa após a adição de turfa foi maior para o fosfato natural reativo, quando comparado ao superfosfato triplo. A eficiência agronômica das fontes SFT e FNR é maior após a adição de condicionador orgânico a base de substâncias húmicas, quando comparado a adição de turfa. A eficiência agronômica relativa das fontes SFT e FNR é maior com a reposição do AC, quando compara a aplicação em dose única no plantio ou parcelado.<br>Tropical soils highly intemperized show increased capability on phosphorus (P) adsorption. Several factors may influence P adsorption in such soils, but special attention must be paid on the organic matter level. Mechanisms involved in this process are related to the release of organic acids derived from the decomposition of the organic matter, which may either have low molecular weight such as malic acids, oxalate and citrates; or may have high molecular weight such as humic and fulvic acids, that act in the complexation of ferric iron and aluminum either in solutions or on colloids surfaces, which, due to a shift of ligands, decrease P adsorption. This research work is comprised by four different studies, all of them performed under greenhouse conditions in the Department of Soil Sciences at ESALQ/USP, mainly aiming to: (i) verify the effect of the addition of organic acids and sources of humic substances on the availability of P in soils with different adsorption capacity. Treatments were performed in two types of soils (Red- Yellow Latosol LVA and LV), two sources of P (monocalcium phosphate - FMC p.a. - and Arad-reactive natural phosphate - FNR), 2 sources of low molecular weight organic acids - AOBM - (citric acid and oxalic acid) and 2 sources of humic substances (soil organic conditioner - CO - and peat - TF). Doses of AOBM were 0, 2, 4 and 8 mmol kg-1, doses of CO were 0, 150, 300 and 600 L ha-1 and doses of TF were 0, 20, 40 and 80 t ha-1; (ii) evaluate the agronomic efficiency of phosphorus sources with variable water solubility, with and without the addition of organic matter. Treatments consisted of two kinds of soils (LVA and LV), two sources of P (triple superphosphate - SFT - and reactive natural phosphate - FNR), three doses of P (0, 50 and 100 mg kg-1) and three doses of peat, corresponding to 0, 25 and 50 t ha-1; (iii) evaluate the effect of the addition of humic substances sources on the agronomic efficiency of P sources. Treatments consisted of 2 soils (LVA e LV), 2 sources of P (SFT and FNR) and 2 sources of humic substances - FSH (CO and TF); and (iv) evaluate the effect of the addition and the way of application of citric acid on the agronomic efficiency of P sources. Citric acid was added in doses corresponding to 0, 4 and 8 mmol kg-1 AC, and exposure methods assessed were: (a) planting (full AC dose applied during planting); (b) reposition = planting + reposition (full AC dose was applied during planting, with the reposition of AC on the 7th, 14th, 21st and 28th day corresponding to 50% of initials doses; (c) partitioned (AC doses were partitioned in four times). Results obtained allowed us to conclude that the addition of low molecular weight organic acids and humic substances sources increased the availability of P, with grater effects in soils of low capacity of P adsorption. The increase on relative agronomic efficiency after the addition of peat was higher for reactive natural phosphate, when compared to triple superphosphate. Agronomic efficiency of SFT and FNR sources is higher when compared to peat addition. Relative agronomic efficiency of SFT and FNR sources was higher with the repositioning of AC, when compared to the exposure to a single dose during planting or partitioned.

Submitted by Marcio Silveira da Silva (marciode@hotmail.com) on 2018-07-26T10:55:51Z No. of bitstreams: 1 Tese-Marcio Silveira da Silva- Ciência do Solo.pdf: 2318239 bytes, checksum: 3034b4bf8c42da6d87fc4bc59a713b5a (MD5)<br>Approved for entry into archive by Karina Gimenes Fernandes null (karinagi@fcav.unesp.br) on 2018-07-26T11:24:31Z (GMT) No. of bitstreams: 1 silva_ms_dr_jabo.pdf: 2318239 bytes, checksum: 3034b4bf8c42da6d87fc4bc59a713b5a (MD5)<br>Made available in DSpace on 2018-07-26T11:24:31Z (GMT). No. of bitstreams: 1 silva_ms_dr_jabo.pdf: 2318239 bytes, checksum: 3034b4bf8c42da6d87fc4bc59a713b5a (MD5) Previous issue date: 2018-05-28<br>O esterco bovino, além de fornecer nutrientes, quando utilizado repetidamente e/ou em grandes quantidades, pode melhorar outros atributos químicos e físicos do solo. Porém, um dos grandes desafios na sua utilização é estimar a quantidade de N que é fornecida durante o ciclo das culturas. Os objetivos com este trabalho foram determinar as alterações nos atributos químicos e físicos do solo, a produtividade de milho e os créditos de nitrogênio derivados da aplicação de esterco bovino e de seu efeito residual. Para alcançá-los foram conduzidos, simultaneamente, dois experimentos, no município de Jaboticabal-SP, em Latossolo Vermelho eutroférrico muito argiloso, durante os anos agrícolas 2011/12; 2012/13; 2013/14 e 2014/15. Ambos os experimentos foram conduzidos em blocos casualizados com quatro repetições. Um dos experimentos foi conduzido para determinar a curva de resposta da cultura do milho ao N, e por meio desta calcular os créditos de nitrogênio provenientes da aplicação do esterco. Para isso, foram aplicadas as doses 0, 60, 90, 120, 180 e 240 kg ha-1 de N-ureia. No outro experimento foram avaliados os efeitos no solo e na planta da aplicação de 0, 5, 10, 15, 30, 45 e 60 Mg ha-1 de esterco bovino e de seu efeito residual, sendo a aplicação do adubo realizada apenas nos dois primeiros anos. Houve melhoria nos atributos químicos do solo pela aplicação de esterco bovino, e a duração dos efeitos foi variável, de modo que para os nutrientes (P, Ca2+, Mg2+ e K+) houve efeito residual e para as variáveis relativas à acidez do solo (pH e H+Al) o efeito não persistiu após a interrupção da aplicação. O teor de carbono orgânico do solo aumentou linearmente com o aumento das doses de esterco, o que levou ao aumento no diâmetro médio dos agregados e na macroporosidade, e diminuição na densidade, mesmo após a interrupção da aplicação do esterco por dois anos e em solo manejado de forma mecânica anualmente. A aplicação de até 60 Mg ha-1 de esterco bovino durante dois anos consecutivos propiciou aumentos na produtividade de grãos de milho nos dois anos de aplicação e nos dois anos de avaliação do efeito residual, sendo que a produtividade média nos anos de aplicação de esterco foi 59% maior. Os créditos de N devidos à aplicação de esterco bovino variaram de 5 a 122 kg ha-1 de N considerando aplicação e efeito residual do adubo e os maiores créditos foram obtidos com a aplicação de 30, 45, 60 e 60 Mg ha-1, respectivamente no primeiro, segundo, terceiro e quarto anos de avaliações.<br>The use of cattle manure, in addition to providing nutrients, when used repeatedly and/or in large quantities, can improve other chemical and physical attributes of the soil. However, one of the major challenges in its use is to estimate the amount of N that is supplied during the crop cycle. The aims of the trials were to evaluate the changes in soil chemical and physical attributes, corn yield and nitrogen credits from the application of cattle manure and its residual effect. In this perspective, two experiments were conducted, simultaneously, in the municipality of Jaboticabal-SP, in an Typic Eutrudox, during the crop seasons 2011/12; 2012/13; 2013/14 and 2014/15. Both trials were conducted in a randomized block with four replicates. One of the trials was conducted to determine the response curve of the corn crop to the N, and through this calculate the nitrogen credits from the application of manure. Rates of 0; 60; 90; 120; 180 and 240 kg ha-1 N-urea. In the other trial, the effects on the soil and on plant of the application of 0, 5, 10, 15, 30, 45 and 60 Mg ha1 of cattle manure and its residual effect were evaluated, applying the fertilizer only in the two first years. There was an enhancement in the chemical attributes of the soil by the application of cattle manure, and the continuance of the effects was variable, so that nutrients (P, Ca2+, Mg2+ and K+ ) had a residual effect and for the variables related to soil acidity (pH and H+ Al) the effect did not persist after the application interruption. The organic carbon content of the soil increased linearly as the rates of manure were increased, which led to the increase in the mean weight diameter of the aggregates and the macroporosity, and decrease in the bulk density, even after the interruption of the application of manure for two years and in a soil plowed annually. The application of up to 60 Mg ha-1 of cattle manure during two consecutive years resulted in increases in grain yield of corn in the two years of application and in the two years of evaluation of the residual effect, and the average yield in the period of application of manure was 59% higher. The N credits due to the application of cattle manure ranged from 5 to 122 kg ha-1 of N considering the application and residual effect of the fertilizer and the highest credits were obtained with the application of 30, 45, 60 and 60 Mg ha-1 , respectively in the first, second, third and fourth years of evaluations.

Orientador: Bruno Coraucci Filho<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo<br>Made available in DSpace on 2018-08-23T02:51:18Z (GMT). No. of bitstreams: 1 Etto_ThiagoLuiz_M.pdf: 1358242 bytes, checksum: 3752bef8769fe4b8d55034f2bc3589b0 (MD5) Previous issue date: 2013<br>Resumo: Devido à crescente preocupação ambiental é esperado um aumento de estações de tratamento de esgoto, e consequentemente dos resíduos por essas gerados. Dentre as formas de destinação final para tal resíduo, destaca-se a incorporação de lodo no solo que atualmente, é regulamentada pela Resolução Conama nº 375 de agosto de 2006 que estabelece os critérios e procedimentos, para aplicação de lodo de esgoto na agricultura. Diversos estudos mostram que a incorporação de lodo na melhora as características físicas e estruturais do solo, além de prover maior quantidade de macro e micronutriente para as plantas que. Atualmente, a incorporação de lodo é calculada com base somente no teor de nitrogênio, sem considerar a quantidade de fósforo a ser incorporada. Apesar desse elemento ser essencial para o desenvolvimento dos vegetais, seu aporte excessivo no meio ambiente pode ocasionar impactos ambientais, especialmente em ambientes aquáticos, onde o elemento provoca a eutrofização. Outro elemento que pode ser acrescido no solo por meio da incorporação de resíduos e pode ser prejudicial às plantas é o sódio. Neste contexto, o presente trabalho se propôs a avaliar as alterações na dinâmica do fósforo e do sódio em solos que receberam a aplicação de lodo de tanque séptica na quantidade 0,0M, 1,0N, 2,0N e 3,0N, correspondente em massa a 0, 2, 4 e 6%, respectivamente. De acordo com os resultados obtidos, a incorporação de lodo de tanque séptico provocou o incremento da capacidade máxima de adsorção até um limitante que possivelmente é dado pela saturação dos sítios de adsorção. Foi constatado também que a incorporação do lodo aumenta a fração mais biodisponível de fósforo. Quanto ao sódio, seus teores foram acrescidos significativamente, todavia, os valores do percentual de sódio trocável - PST e a razão de adsorção de sódio - RAS se manteve. Assim, o trabalho conclui que a incorporação de lodo de tanque séptico é interessante, uma vez que contribui para a melhoria da fertilidade do solo, em especial, a disponibilidade de fósforo para as culturas, e, apesar de aumentar o sódio trocável, pode não alterar a PST e a RAS<br>Abstract: Due to growing environmental concern is expected a sewage treatment plants, increase and consequently solid waste generated by them. Among the forms of disposal for such waste, highlights the incorporation of sludge in soil that is currently regulated by CONAMA Resolution 375 of August 2006 establishing criteria and procedures for application of sewage sludge in agriculture. Several studies show that the incorporation of slime improves the physical and structural characteristics of soil, and provide large quantity of macro-and micro-nutrient for plants. Currently, the incorporation of sludge is calculated based only on the content of nitrogen, without regarding the amount of phosphorus being incorporated. Although this element is essential to plants development, their contribution to excessive environmental impacts can especially result in aquatic environments, where the element causes eutrophication. Another element may be added into the soil through the incorporation of residues and may be harmful to plants is sodium. In this context, the present work aimed to evaluate the changes in the dynamics of phosphorus and sodium in soils which was amended with the application of septic tank sludge amount in 0.0 N, 1.0 N, 2.0 N and 3.0 N, corresponding mass at 2, 4 and 6%, respectively. According to the results, the incorporation of septic tank sludge has caused the increase of the maximum adsorption capacity to a limiter which is possibly given by the saturation of the adsorption sites. It was also found that the incorporation of sludge increases more bioavailable fraction of phosphorus. As the sodium content was significantly increased, however, the values of exchangeable sodium percentage - ESP and sodium adsorption ratio - SAR remained. Thus, the paper concludes that the incorporation of septic tank sludge is interesting, since it contributes to improving the soil fertility, in particular, the availability of phosphorous for crops and, despite increasing the exchangeable sodium cannot change the PST and the RAS<br>Mestrado<br>Saneamento e Ambiente<br>Mestre em Engenharia Civil

A cana-de-açúcar têm despertado o interesse mundial como fonte alternativa de energia renovável. Para que a cultura se estabeleça globalmente como alternativa à produção de bioenergia, questões de sustentabilidade devem ser consideradas. Nesse sentido, a fertilização nitrogenada desempenha papel fundamental, pois influencia a produtividade do canavial e, por outro lado, pode ocasionar impactos ao ambiente se manejada inadequadamente. O objetivo deste estudo foi elucidar questões recentemente levantadas a respeito do manejo da cana-de-açúcar em áreas colhidas sem queima, tais como (i) a colheita mecanizada sucessiva poderá ocasionar degradação física do solo que comprometerá o desenvolvimento do sistema radicular da cultura? (ii) a aplicação de elevadas doses de N sobre a palha e sem o cultivo das soqueiras irá alterar a arquitetura radicular da cana-de-açúcar? e (iii) é possível desenvolver métodos diagnósticos de N do solo para dar suporte ao manejo da adubação nitrogenada da cana-de-açúcar? Três estudos foram desenvolvidos para elucidar as questões acima descritas. Do primeiro capítulo conclui-se que a colheita mecanizada sucessiva do canavial, sem o cultivo da soqueira, altera as propriedades físicas da camada superficial do solo, com efeito negativo na densidade radicular da cultura. Valores de resistência à penetração (RP) inferiores a 0,75 MPa não comprometem o crescimento radicular da cana, porém RP entre 0,75 a 2,0 MPa diminui a densidade radicular e, a partir de 2,0 MPa, há restrição severa ao crescimento radicular. O segundo capítulo apresentou a variação no crescimeno radicular da cana-de-açúcar no ciclo de primeira soqueira, em duas áreas (Usina Santa Adélia, USA e São Martinho, USM) e em função de doses de N aplicadas no plantio (0 ou 120 kg ha-1 N) e na soqueira (0 e 150 kg ha-1 N). O efeito da adubação nitrogenada no crescimento de raízes da cana-de-açúcar variou entre as áreas. Em ambos experimentos, a variação na biomassa de raízes durante o ciclo foi mais influenciada pelas propriedades dos solos do que pelas doses de N. Na área da USM a adubação nitrogenada de soqueira aumentou a densidade de raízes na camada superficial (0-0,2 m) e próximo às plantas (<0,3 m), enquanto que no experimento da USA nenhum efeito foi observado. Não houve efeito residual da adubação nitrogenada de plantio na biomassa e no acúmulo de N nas raízes e na parte aérea. A aplicação de altas doses de N na superfície do solo e sobre a palha não alterou significativamente a arquitetura do sistema radicular da cultura. O terceiro capítulo avaliou a resposta à adubação nitrogenada de soqueira em dez experimentos de campo no Estado de São Paulo. Os solos foram divididos em altamente responsivo, moderadamente responsivos e não responsivos. Estudos subsequentes em laboratório mostraram que os solos diferiram quanto à capacidade de fornecimento de N. A mineralização bruta separou adequadamente os solos quanto à responsividade ao N, enquanto o testes químicos Illinois Soil Nitrogen Test e Destilação a Vapor Direta apresentaram resultados promissores, podendo ser realizados em laboratórios de rotina de análise de solo em um dia de serviço. Estudos adicionais devem ser realizados para verificar a viabilidade de testes de N no solo para melhorar o manejo da adubação nitrogenada da cana-de-açúcar.<br>Sugarcane has been a promissing crop for renewable energy production around the world. In order to establish sugarcane as a globally alternative for bioenergy production, sustainability issues should be considered. Synthetic nitrogen (N) fertilizers plays a key role in sugarcane production but, if used improperly, causes environmental threats. The goal of this study was to elucidate current questions about sugarcane management in unburned areas, as follows (i) the sucessive mechanical harvesting could decrease the soil physical quality and thus compromise root system development? (ii) applying high N rates over the sugarcane straw, without further cultivation would modify the sugarcane root architecture? and (iii) is it possible to use soil N mineralization indexes in order to improve the N management of sugarcane? Three studies were carried out in order to elucidate the aforementioned issues. The findings of the first study is that successive mechanical harvesting without further soil cultivation modify the physical properties of the superficial soil layer, with negative effects on root density. No limitations on root growth occurs when penetration resistance (PR) is lower than 0,75 MPa, but PR from 0,75 to 2,0 MPa decreases root density and PR higher than 2,0 MPa causes severe restriction to root growth. The second study shows the variation in sugarcane root growth over the first ratoon cycle in two trials (Santa Adelia Mill, USA and Sao Martinho Mill, USM) as related to N rates applied at planting (0 or 120 kg ha-1 N) and to the ratoon (0 and 150 kg ha-1N). The effect of N fertilizer addition in sugarcane rooting varied between sites. In both trials, the variation in root biomass was more influencied by soil properties than by N supply. At USM site, ratoon N fertilization increased root density in the superficial soil layer (0-0,2 m) and close to the plants (<0,3 m), while at the SA site no effect of N was observed. There was no carry over effect from N applied at planting in the evaluated parameters (root and shoot biomass and N accumullation). Applying high N rates over the sugarcane straw does not affect significantly the sugarcane root architecture. The third study assess the N fertilizer response of sugarcane in ten field trials at Sao Paulo State. The soils were categorized in highly responsive, moderately responsive and non-responsives to N fertilization. Further studies developed under laboratory conditions showed differences in the soil\'s N supplying power. The gross mineralization succesfully identified the soils responsiveness to N, and the chemical tests Illinois Soil Nitrogen Test and Direct Steam Distilation showed promising results and can be performed in routine soil analysis in one work day. Further studies are warranted to assess the feasibility in using soil N tests to improve N fertilizer management in sugarcane.

A colheita sem queima da cana-de-açúcar favorece o acúmulo de resíduos na superfície, aumentando os teores de C e N no solo. A quantificação do N mineralizado é de grande interesse, pois a matéria orgânica do solo (MOS) é o principal reservatório de N para as plantas. Embora a mineralização da MOS forneça quantidades apreciáveis de N mineral, a fertilização nitrogenada se faz necessária para a manutenção de produtividades elevadas na cultura. Devido à espessa camada de palha, a aplicação dos fertilizantes nitrogenados é realizada geralmente sobre o solo, intensificando o processo de volatilização de NH3 quando a uréia é utilizada. A primeira parte deste estudo avaliou e comparou métodos biológicos para estimativa do N mineralizável em solos cultivados com cana-de-açúcar. Foram utilizadas amostras de cinco solos, coletadas nas profundidades de 0-20, 20-40 e 40-60 cm. As amostras de solo foram incubadas aerobiamente a 35°C, durante 32 semanas, e anaerobiamente (waterlogged) a 40°C, por 7 dias. Os teores de areia, silte e argila foram os melhores índices para estimar o N mineralizável do solo. Na incubação aeróbia de longa duração, o N mineralizado acumulado apresentou maior sensibilidade em relação N potencialmente mineralizável para a predição da mineralização líquida de N. A incubação anaeróbia de curta duração pode ser utilizada em rotina de laboratórios. A manutenção do N-NH4+ pré-existente nas amostras proporcionou melhores estimativas do N mineralizável do solo com o método da incubação anaeróbia. O segundo experimento avaliou a variação temporal do N inorgânico em um LATOSSOLO VERMELHO distrófico (LVd) e LATOSSOLO VERMELHO-AMARELO eutrófico (LVAe) relacionada à fertilização nitrogenada em soqueiras de cana-de-açúcar. Os tratamentos constaram das fontes: Ajifer®, cloreto de amônio, nitrato de amônio, uréia e YaraBela NitromagTM, na dose de 100 kg ha-1 de N; uréia nas doses: 50, 100, 150 e 200 kg ha-1 de N e uma testemunha. No LVd, o Ajifer® e YaraBela NitromagTM inicialmente aumentaram os teores de N-NH4+ na camada de 0-20 cm, enquanto que a aplicação de YaraBela NitromagTM, nitrato de amônio, Ajifer® e as doses de 150 e 200 kg ha-1 de N-uréia incrementaram a quantidade de N-NO3- nas profundidades de 0-20 e 20-40 cm. Após 44 dias, o N mineral do solo decresceu abruptamente devido à absorção pelas plantas e imobilização microbiana. A aplicação de N no LVAe não modificou a disponibilidade do nutriente no solo. O terceiro ensaio avaliou a eficiência de um coletor aberto na quantificação do N-NH3 volatilizado da uréia aplicada sobre a palhada de cana-de-açúcar. As perdas de N-NH3 foram estimadas pelo coletor semi-aberto estático (CSA) e coletor aberto com absorvedor envolto em película de politetrafluoroetileno (CA). A uréia foi aplicada superficialmente e em faixa, em tratamentos que corresponderam às doses de 50, 100, 150 e 200 kg ha-1 de N. O CA não alterou a quantidade de N-NH3 volatilizada em relação ao CSA. A eficiência do CA variou de forma não-linear, em função da taxa de N-NH3 volatilizado, com valor médio de 58,4% na faixa de 100 a 200 kg ha-1 de N-uréia.<br>Harvesting sugarcane without burning favors the straw surface accumulation and C and N storage. Quantification of N mineralization is of great importance because soil organic matter (SOM) is the major N pool for plants. Although SOM mineralization provide appreciable amounts of mineral N, the fertilization is necessary for maintaining high yields. Due to the thick straw layer, the N fertilizer is applied normally above the residue, enhancing the NH3 volatilization process when urea is used. The first part of this study evaluated and compared biological methods to estimate N mineralization in soils cropped with sugarcane. Five soils samples were collected at 0-20, 20-40 and 40-60 cm depths. The soil samples were incubated aerobically at 35°C for 32 weeks, and anaerobic (waterlogged) at 40°C for 7 days for determination of net soil N mineralization. The sand, silt and clay fractions were the best indices for estimating soil N mineralization. The mineralized N accumulated in the long-term aerobic incubation showed higher sensitivity towards N mineralization potential to predict net N mineralization. The short-term anaerobic incubation can be used in laboratories routine. Maintaining the pre-existing NH4+-N of samples was advantageous to improve the mineralizable soil N estimation with the anaerobic incubation method. The second experiment evaluated the temporal inorganic N variation in a Typic Hapludox (TH) and Typic Eutrustox (TE), related to N fertilization of a sugarcane ratoon. The treatments were the sources: Ajifer®, ammonium chloride, ammonium nitrate, urea and YaraBela NitromagTM, at 100 kg ha-1 N dose; urea rates: 50, 100, 150 and 200 kg ha-1 N and a control. In TH, the Ajifer® and YaraBela NitromagTM initially increased the levels of NH4+-N at the 0-20 cm depth, while Ajifer®, ammonium nitrate, YaraBela NitromagTM and rates of 150 and 200 kg ha-1 urea-N raised the amount of NO3--N at 0-20 and 20-40 cm depths. After 44 days, mineral N decreased sharply due to the N uptake by plants and microbial immobilization. The N sources and N-urea rates in TE did not change the soil N availability. The third trial evaluated the effectiveness of an open collector for quantification of NH3-N volatilized from urea applied on sugarcane trash blankets. The NH3-N losses were estimated by semi-open static collector (SOC) and open collector absorber wrapped in polytetrafluoroethylene film (OC). Urea was applied in band on soil surface at rates of 50, 100, 150 and 200 kg ha-1 N. The OC did not alter the amount of NH3-N in relation to SOC. The OC effectiveness ranged non-linearly with the NH3-N rate and showed an average of 58.4% on the range of 100 to 200 kg ha-1 urea-N.

Os fertilizantes nitrogenados desempenham função importante na nutrição e aumento da produtividade da cana-de-açúcar, porém alteram os processos de transformação de C e N do solo. Este trabalho teve por objetivo principal avaliar o efeito da aplicação consecutiva de fertilizantes minerais e orgânicos nas transformações microbianas, na mineralização do N, nos estoques de C, N total e N mineral, e na fertilidade do solo a médio prazo. Foram escolhidas duas áreas cultivadas com cana-de-açúcar no Estado de São Paulo nas quais experimentos com manejo da adubação nitrogenada foram conduzidos desde 2010 e 2011, com reaplicação anual dos tratamentos até 2014. Nestas áreas foi adotado o delineamento estatístico casualizado em blocos com quatro repetições. Os tratamentos foram: controle (sem adubação nitrogenada), adubação com as fontes nitrato de amônio, ureia, composto orgânico e Ajifer&reg; na dose 100 kg ha-1 ano-1 N, e adubação com a fonte YaraBella NitromagTM nas doses de 50, 100, 150 e 200 kg ha- 1 ano-1 N. Para avaliar o efeito dos tratamentos na variação da fertilidade do solo e no teor de N orgânico hidrolisável (N-ISNT), foram realizadas amostragens de solo anuais nestes experimentos nas camadas de 0-20 e 20-40 cm. Para avaliar o efeito dos tratamentos nos processos de transformação do C e N do solo, em 2014 foram coletadas amostras de solo até 100 cm de profundidade nos tratamentos controle, composto orgânico, YaraBella NitromagTM nas doses 100 e 200 kg ha-1 ano-1 N e mata nativa, nas quais foram determinados a densidade do solo e teores de C orgânico, N total e N mineral (N-NH4+ e N-NO3- + N-NO2-). Adicionalmente, amostras da camada de 0-20 cm foram incubadas em laboratório para avaliar a disponibilidade temporal de N e os teores de C e N da biomassa microbiana e sua atividade. Os efeitos da adubação nitrogenada consecutiva foram pouco expressivos nas transformações microbianas, na disponibilidade temporal de N mineral e nos estoques de C e N do solo; entretanto, foi observado acúmulo de N mineral em camadas mais profundas (> 40 cm) para a dose de 200 kg ha-1 ano-1 N. Além disso, a área de mata apresentou melhores atributos microbiológicos e maior estoque de C e N comparado às áreas cultivadas com cana-de-açúcar. Em relação à variação da fertilidade do solo, observou-se que o aumento das doses de N potencializa a acidificação do solo em anos consecutivos, assim como promove diminuição do teor de bases trocáveis. A manutenção da fertilidade do solo, dos atributos microbiológicos, e dos estoques de C, N total e N mineral para produção sustentável de biocombustíveis depende do manejo adequado da fertilização nitrogenada no sistema de colheita dos canaviais sem prévia queima. De forma complementar e paralela a estes trabalhos, foi objeto de estudo a adaptação e validação de métodos colorimétricos na determinação de N inorgânico em extratos de solos tropicais. Os resultados revelaram que é necessário adicionar carvão ativado durante o processo de extração para que os métodos colorimétricos apresentem melhor exatidão e precisão. Recomenda-se utilizar solução extratora de KCl 2,0 mol L-1 e permitir tempo de reação de 30 min. A faixa linear de trabalho mais adequada varia de 0 a 7,5 e 0 a 10,0 mg L-1 de N para leituras de N-NH4+ e N-NO3- respectivamente.<br>Nitrogen fertilizers play an important role in nutrition and increased productivity of sugarcane, however, affect cycling of C and N in the soil. This study mainly aimed to evaluate the effect of the consecutive application of organic and inorganic sources of N in microbial soil transformations, in N mineralization, in C, total N and mineral N stocks, and soil fertility in the medium term. They were chosen two areas cultivated with sugarcane in the State of São Paulo in which experiments with management of nitrogen fertilization have been conducted since 2010 and 2011, with annual reapplication of treatments through 2014. In these areas was adopted the randomized blocks experimental design, with four replications. The treatments were: control (no nitrogen fertilization), fertilization with sources of ammonium nitrate, urea, organic fertilizer and Ajifer&reg; at rate of 100 kg ha-1 yr-1 N, and fertilization with YaraBella NitromagTM source at rates of 50, 100, 150 and 200 kg ha-1 yr-1 N. To evaluate the effect of treatments on the variation of soil fertility and hydrolysable organic-N fraction (N-ISNT), annual soil samples were collected in these experiments at 0-0.2 and 0.2-0.40 m. To evaluate the effect of treatments on soil C and N transformations, soil samples were collected up to 1.0 m depth in the control, organic fertilizers, YaraBella NitromagTM at rates of 100 and 200 kg ha-1 yr-1 N treatments and bushland, in which were determined bulk density and organic C, total N and mineral N (NH4+-N and NO2--N + NO3--N). In addition, soil samples of the 0-0.2 m were incubated in the laboratory to assess the availability of N and the content of C and N microbial biomass and microbial activity. The effects of consecutive nitrogen fertilizer were inexpressive in microbial transformations, in the temporal availability of mineral N and C and N soil stocks; however, it was observed mineral N accumulation in deeper layers (> 0.4 m) at rate of 200 kg ha-1 yr-1 N. Moreover, the bushland showed better microbiological attributes and largest C and N soil stocks compared with areas cultivated with sugarcane. In relation to the variation of soil fertility, it observed that the increase in N rates enhances the soil acidification in consecutive years, and promotes decreased levels of exchangeable bases. The maintenance of soil fertility, the microbiological attributes, and the C, total N and mineral N soil stocks for sustainable biofuel production depends on proper management of nitrogen fertilization on crop system of without burning sugarcane fields. Complementarily and in parallel with these studies, it was the object of study the adaptation and validation of colorimetric methods for the determination of inorganic N in tropical soil extracts. The results revealed that it is necessary to add activated charcoal during the extraction process so that colorimetric methods exhibit better accuracy and precision. It is recommended to use extraction solution of KCl 2,0 mol L-1 and allow 30 min reaction time between addition of reagent and the spectrophotometer reading. The linear working range more suitable varies from 0 to 7.5 and 0 to 10,0 mg L-1 of N for measurement of NH4+-N and NO3--N respectively.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES<br>Effect of animal manure use in soil is most diverse and has great importance, which is influenced directly or indirectly by carbon (C) added to soil. In Brazil, there is a lack of information in long - term experiments comparing effect of manures types and mineral fertilizer on soil organic carbon (SOC) stock and in labile and stable fractions of soil organic matter (SOM). The objective of this work was to investigate the impact of successive long-term applications of manure and mineral fertilizer over 12 years on soil C stock and physical fractions of SOM. The study was conducted in an experiment from 2004 to 2016 in Santa Maria, Rio Grande do Sul, Brazil. The treatments consisted of application of Mineral Fertilizer (MF); Pig Slurry (PS); Cattle Slurry (CS); Pig Deep Litter (PDL) and Control, without fertilization (Cont). C stock in soil profile (0-70 cm) was quantified after 4 and 12 years, and the C stock in free light fraction (FLF), occluded light fraction (OLF), particulate (Part) and associated to silt and clay (S + C) of SOM after 12 years. Manure use yielded higher increases in C stock in soil and in SOM fractions in relation to MF. These effects were verified up to 10 cm, and were more marked with the use of PDL and CS. PDL and CS use in long term increases C stock in soil and favors SOM protection by C accumulation in organo-minerais complexes and C occlusion in aggregates. This suggests that C derived from of PDL and CS are relatively stable and of great importance in SOM stabilization.<br>Os efeitos do uso de dejetos de animais no solo são os mais diversos e de grande importância, sendo muitos deles influenciados direta ou indiretamente pelo carbono (c) adicionado ao solo. No Brasil não há informações suficientes em experimentos de longa duração comparando o efeito de diferentes tipos de dejetos e fertilizante mineral no estoque de carbono orgânico do solo (COS) e em frações lábeis e estáveis da matéria orgânica do solo (MOS). O objetivo desse trabalho foi investigar o impacto de aplicações sucessivas de dejetos de animais e fertilizante mineral ao longo de 12 anos no estoque de C do solo e em frações físicas da MOS. O estudo foi realizado em um experimento conduzido de 2004 a 2016 em Santa Maria, Rio Grande do Sul, Brasil. Os tratamentos consistiram na aplicação de Fertilizante Mineral (FM); Dejeto líquido de suínos (DLS); Dejeto liquido de bovino (DLB); Cama sobreposta de suínos (CSS) e Controle, sem aplicação de nutrientes (Cont). Quantificou-se o estoque de C em camadas no perfil do solo (0-70 cm) após 4 e 12 anos, e o estoque de C nas frações leve livre (FLL), leve oclusa (FLO), particulada (Part) e associada a silte e argila (S+A) da MOS após 12 anos. Os dejetos proporcionaram maiores aumentos no estoque de C no solo e nas frações da MOS em relação ao FM. Esses efeitos foram verificados até 10 cm, sendo mais marcantes com o uso de CSS e DLB. A utilização de CSS e DLB em longo prazo aumenta o estoque de C no solo e favorece a proteção da MOS pelo acumulo de C em complexos organo-minerais e pela oclusão de C em agregados. Isso sugere que o C derivado da CSS e do DLB são relativamente estáveis e tem grande importância na estabilização da MOS.

O Brasil ocupa a quarta posição entre os maiores produtores mundiais de carne suína. Destaque nacional deve ser dado ao estado de Santa Catarina, que detém 25% da produção do Brasil. Em Santa Catarina, a intensificação da produção em pequena área territorial gera um grande aporte anual de dejetos de suínos por unidade de área agrícola. Isso se deve ao fato de que a alternativa mais utilizada para descarte desses resíduos é a sua aplicação como fertilizante agrícola, prática que tem gerado um dos maiores problemas de poluição ambiental, especialmente na região Oeste Catarinense. Poucos trabalhos com intuito de avaliar a toxicidade desse material aos organismos edáficos e sua interação com diferentes classes texturais de solos podem ser encontrados. Para avaliação desta toxicidade, uma ferramenta utilizada internacionalmente, e cada vez mais frequentemente no Brasil, é a ecotoxicologia terrestre. Esta técnica é utilizada para avaliar efeitos de substâncias que, quando adicionadas aos solos, causam impactos em organismos, mensurando as respostas de alterações na taxa de letalidade, reprodução, desenvolvimento e comportamento de organismos edáficos padronizados. Desta maneira, este estudo objetivou avaliar por meio de testes ecotoxicológicos os efeitos de doses crescentes de dejeto de suínos (D0: 0 m3 ha-1; D1: 25 m3 ha-1; D2: 50 m3 ha-1; D3: 75 m3 ha-1 e 100 m3 ha-1), em diferentes tipos de solo (Argissolo Vermelho Eutrófico S2; Latossolo Vermelho Distrófico S3 e Neossolo Quartzarênico S4 e Solo Artificial Tropical S1) na sobrevivência, reprodução e comportamento de minhocas (Eisenia andrei) e colêmbolos (Folsomia candida), através de metodologias padronizadas internacionalmente. Os resultados das avaliações com Eisenia andrei mostraram que no solo com menor teor de argila a toxicidade do dejeto causou letalidade de 100% dos indivíduos nas duas maiores doses testadas. Para os testes de toxicidade crônica, avaliando o potencial reprodutivo, as doses testadas em Neossolo Quartzarênico tiveram efeitos negativos em Eisenia andrei, mas nos outros solos não ocorreu efeito perceptível. Os resultados obtidos para testes com Folsomia candida mostraram toxicidade em todas as doses testadas, causando letalidade significativa dos indivíduos na menor dose de dejeto aplicada e, baseado nessa resposta, doses menores foram usadas para avaliar efeito crônico e no comportamento (0 m3 ha-1, 10 m3 ha-1, 15 m3 ha-1, 20 m3 ha-1 e 25 m3 ha-1). Os efeitos das doses usadas para o teste de reprodução foram significativamente diferentes dos observados no controle causando redução no número de juvenis gerados em todos os solos testados. As doses D3 e D4 no S2, assim como todas as doses no S3 causaram significativa fuga de colêmbolos para o solo não contaminado. Os resultados obtidos revelam a importância da utilização de solos naturais de diferentes texturas e diferentes organismos na avaliação de toxicidade de dejetos de suínos e também mostram que nesse caso os resultados dos testes com solo artificial tropical não podem ser extrapolados para solos naturais.<br>Brazil occupies the fourth place worldwide among the largest swine producers. National highlight should be given to Santa Catarina State, which stands for 25% of this production. In this state, the intensification of the production in a small area leads to a yearly huge supply of swine manure per unit of agricultural area. This is due to the fact that the most used methods to dispose swine manure is its application as a fertilizer on soils, which has been causing one of the largest environmental pollution problems, especially in the Western region of Santa Catarina State. Very few studies are available aiming to evaluate swine manure toxicity on edaphic organisms and its interaction with different textural classes of soil. To evaluate this toxicity ecotoxicology has been used around the world, and increasingly in Brazil. This technique is used to assess the effects of substances that, when applied on soil, cause impacts on the organisms, measuring their responses with regard to mortality rates, reproduction, development and behavior of soil organisms. Thus, this study aimed to evaluate, by means of ecotoxicological tests the effects of increasing swine manure doses (D0: 0 m3 ha-1; D1: 25 m3 ha-1; D2: 50 m3 ha-1; D3: 75 m3 ha-1 e 100 m3 ha-1) in different types of soil (Ultisols - S2; Oxisol S3 and Entisols S4) and in an Tropical Artificial Soil S1, on the survival, reproduction and behavior of earthworms (Eisenia andrei) and springtails (Folsomia candida), using standard international methodologies. The results of Eisenia andrei evaluations showed that, in sandy soils, swine manure toxicity caused 100% mortality of the organisms at the two largest doses tested. For chronic toxicity tests, evaluating the reproductive potential, there were negative effects of tested doses on Eisenia andrei in Entisols, but for the other soils there was no perceptible effect. The results of Folsomia candida tests showed toxicity for all the tested doses, causing significant mortality of the organisms even at the smallest dose applied. Therefore, smaller doses were used to evaluate chronic and behavioral effects (0 m3 ha-1, 10 m3 ha-1, 15 m3 ha-1, 20 m3 ha-1 e 25 m3 ha-1). The effects of applied doses for the reproduction test were highly different from those observed in the control treatment, always causing reduction in the number of produced juveniles for all types of soil tested. The D3 and D4 doses for S2, as well as, all the doses for S3, showed significant avoidance of springtails towards the uncontaminated soil. These data show the importance of the usage of natural soils with different textural classes and also different organisms in the evaluation of swine manure toxicity. Also, they show that the results for artificial tropical soils cannot be extrapolated to natural soils.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The use of pig slurry as a source of nutrients can affect the conditions of acidity and nutrient availability, altering the environment for crop development. The objective of this study was to evaluate changes in chemical properties of an Alfisol after 95 months of cultivation and 19 applications of pig slurry, conducted under no-tillage system. The experiment was installed in May 2000, an experimental area under no-tillage at the Federal University of Santa Maria, and conducted until January 2008. The experimental design was a randomized block design with three replications. Were performed nineteen surface applications of 0, 20, 40 and 80 m3 ha-1 of pig slurry during the experiment and in the end, were collected samples of soil layers of 0-2, 2-4, 4 -6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 and 50-60 cm depth. The soil was collected with the aid of a spade cut-off, air dried, milled manually with the aid of a roller and passed through a sieve with 2 mm mesh and reserved. It was determined the pH values in water (1:1), SMP, the levels of exchangeable Al, Ca, Mg and K. With the data obtained were calculated the sum of bases, base saturation and Al saturation, CEC pH7, CEC effective and potential acidity (H + Al). Were also determined the total contents of N, P and K, levels of mineral N, available P and soil organic matter. The successive application of pig slurry promoted increase in pH values in water up to 8 cm of soil, however, no change in potential acidity. Also caused increased levels of exchangeable Ca and Mg in the surface layers of soil, reflecting an increase in the values of sum of bases, base saturation and decreasing Al saturation. Furthermore, the applications over time caused an increase in levels of soil organic matter, reflecting in increased levels of total N to a depth of 30 cm. Applications of manure resulted in increased levels of available P and exchangeable K to a depth of 60 cm, while for the total P increases were observed up to 30 cm depth. The changes observed in soil chemical properties provides better environment for root development of crops due to lower acidity and higher nutrient availability in soil solution. However, one must be careful in extrapolating these results to different soils, although the phenomena are similar, they occur in different magnitudes depending on soil characteristics.<br>A utilização de dejeto líquido de suínos como fonte de nutrientes pode afetar as condições de acidez e de disponibilidade de nutrientes, modificando o ambiente para o desenvolvimento das culturas. O objetivo do presente trabalho foi avaliar as alterações nos atributos químicos de um Argissolo após 95 meses de cultivo e 19 aplicações de dejeto líquido de suínos, conduzido sob sistema de plantio direto. O experimento foi instalado em maio de 2000, numa área experimental sob sistema plantio direto na Universidade Federal de Santa Maria, e conduzido até janeiro de 2008. O delineamento experimental foi de blocos ao acaso com três repetições. Foram realizadas dezenove aplicações superficiais de 0, 20, 40 e 80 m3 ha-1 de dejeto líquido de suínos, durante a condução do experimento e, ao final, foram coletadas amostras do solo nas camadas de 0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16- 18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 e 50-60 cm de profundidade. O solo foi coletado com o auxílio de uma pá-de-corte, seco ao ar, moído manualmente com o auxílio de um rolo destorroador e passado em peneira com malha de 2 mm e reservado. Foram determinados os valores de pH em água (1:1), índice SMP, os teores trocáveis de Al, Ca, Mg e K. Com os dados obtidos foram calculadas a soma de bases, saturação por bases e por Al, CTC pH7,0, CTC efetiva e acidez potencial (H+Al). Também foram determinados os teores totais de N, P e K, os teores de N mineral, P disponível e matéria orgânica do solo. A aplicação sucessiva de dejeto líquido de suínos promoveu incremento nos valores de pH em água do solo até 8 cm, no entanto, não houve alteração nos valores de acidez potencial. Também provocou aumento nos teores trocáveis de Ca e Mg nas camadas superficiais do solo, refletindo em aumento nos valores de soma de bases, saturação por bases e diminuindo a saturação por alumínio. Além disso, as aplicações ao longo do tempo promoveram aumento nos teores de matéria orgânica do solo, até 60 cm de profundidade, refletindo em aumento nos teores de N total até a profundidade de 30 cm. As aplicações de dejeto provocaram incremento nos teores de P disponível e K trocável até a profundidade de 60 cm, enquanto que para o P total os incrementos foram observados até 30 cm de profundidade. As alterações observadas nos atributos químicos do solo proporcionam melhor ambiente para o desenvolvimento radicular das culturas devido à redução da acidez e maior aporte de nutrientes na solução do solo. No entanto, deve-se tomar cuidado ao extrapolar esses resultados para solos com características diferentes, embora os fenômenos se assemelhem, estes ocorrem em magnitudes diferentes dependendo das características do solo.

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-06-01T13:47:37Z No. of bitstreams: 1 SAMIRES DO NASCIMENTO SILVA - DISSERTAÇÃO PPGSA PROFISSIONAL 2014..pdf: 973646 bytes, checksum: 270edb29910dc87c2a25e82051b0f47a (MD5)<br>Made available in DSpace on 2018-06-01T13:47:37Z (GMT). No. of bitstreams: 1 SAMIRES DO NASCIMENTO SILVA - DISSERTAÇÃO PPGSA PROFISSIONAL 2014..pdf: 973646 bytes, checksum: 270edb29910dc87c2a25e82051b0f47a (MD5) Previous issue date: 2014-09<br>A preocupação com a qualidade do solo tem crescido à medida que seu uso e mobilização intensiva passaram a resultar em diminuição da sua capacidade produtiva e sustentável ao longo dos anos. Objetivou-se com o trabalho avaliar a qualidade de solo em pomar de mangueiras (Mangífera indica L.) var. Tommy atkins adubadas com fontes orgânicas no semiárido paraibano, por meio dos atributos químicos, físicos e biológicos do solo. O experimento foi conduzido no Setor de Fruticultura do IFPB Campus Sousa, em delineamento inteiramente casualizado, com oito tratamentos e três repetições, totalizando 24 unidades experimentais. Realizou-se a coleta de solo, em outubro de 2013, na profundidade 0-20 cm, em cada unidade experimental. Para os atributos químicos foram avaliados: o pH em água, a condutividade elétrica no extrato 1:5; os teores de Ca+2, Mg+2, Na+, K+ trocáveis e P assimilável e os teores de carbono total e estimou-se os valores de: saturação por base e percentagem de sódio trocável. Com os teores de carbono total, obtiveram-se os teores de matéria orgânica. Quanto aos atributos físicos avaliou-se: os teores de areia, silte e argila, o grau de floculação, densidade de partículas, densidade do solo e a porosidade total. Os atributos biológicos avaliados foram: ocorrência e densidade de microrganismos, respiração edáfica, C da biomassa e quociente metabólico. Não foram encontradas diferenças significativas estatisticamente para os atributos químicos e físicos indicadores da qualidade do solo. Os maiores valores observados para o quociente metabólico foram para o esterco de aves e para o composto orgânico. A análise de componentes principais possibilitou a visualização conjunta dos atributos químicos, físicos e biológicos, verificando como os atributos foram afetados pela presença ou ausência de fontes orgânicas.<br>Concern for soil quality has grown as its use and intensive mobilization began to result in a decrease of its productive capacity and sustainable over the years. The objective of the study was to evaluate the quality of soil in an orchard of mango (Mangifera indica L.) var. Tommy atkins fertilized with organic sources in semiarid Paraiba, through chemical, physical and biological soil properties. The experiment was conducted at the Department of Fruit Crops IFPB Campus Sousa, in a completely randomized design with eight treatments and three replications, totaling 24 experimental units. Held the soil collected in October 2013 at 0-20 cm depth in each experimental unit. For chemical attributes were evaluated: pH, electrical conductivity extract 1: 5; the Ca2+, Mg2+, Na+, K+ and exchangeable P assimilable and the contents of total carbon and estimated the values of: base saturation and exchangeable sodium percentage. With the levels of total carbon, obtained the contents of organic matter. As for physical attributes is evaluated: the proportions of sand, silt and clay, the degree of flocculation, particle density, bulk density and total porosity. The biological attributes evaluated were: occurrence and density of microorganisms, soil respiration, biomass C and metabolic quotient. No statistically significant differences were found for physical and chemical indicators of soil quality attributes. The highest values were observed for the metabolic quotient were for poultry manure and organic compost. The principal component analysis allowed the joint visualization of chemical, physical and biological attributes, checking how the attributes were affected by the presence or absence of organic sources.

Land application of wood ash is becoming more appealing, as a disposable alternative, to landfilling options. It is estimated that 110,000 tonnes of wood ash is produced annually in Alberta by cogeneration systems, a large percentage produced in Central and Peace River Regions of Alberta. Alkaline (pH-13) properties and nutrient content of wood ash provides an alternative for the acidic and nutrient deficient soils within these regions. The objective of this field study was to determine the effect wood ash applications would have under field conditions on: the chemical and physical properties of soils; barley dry matter production; grain and seed yield of barley and canola; and the nutrient and metal uptake by crop tissue. Ash applications significantly increased dry matter and seed yield, improved crop nutrient quality, increased soil pH and improved soil nutrient availability, while not infringing on any environmental regulations.<br>xxiii, 142 leaves : ill. ; 28 cm.

Органска ђубрива садрже готово све неопходне хранљиве елементе за гајене биљке, али имају значајно мању ефикасност од синтетичких ђубрива јер је садржај хранива неупоредиво нижи у односу на синтетичка, а облици у којима се налазе нису директно приступачни гајеним биљкама. Циљ истраживања био је да се испита утицај примене различитих органских ђубрива биљног и животињског порекла, као и течних ђубрива на хемијска својства земљишта, принос и квалитет јагоде у оквиру два система производње (малчирања земљишта). Пољски оглед је постављен као двофакторијални по методи/плану подељених парцела (Split/plot), са случајним распоредом третмана. Оглед се састојао од две главне парцеле на којима је испитан утицај два различита начина покривања земљишта (малч од сламе и црна полиетиленска фолија), док је на основним парцелама испитан утицај 13 различитих третмана ђубрења (контрола &ndash; без примене ђубрива, &Oslash;; говеђи стајњак, С; говеђи стајњак + гуано (фолијарно), С+Г; говеђи стајњак + екстакт глистењака (фолијарно), С+ЕГ; глистењак, ГЛ; глистењак + гуано (фолијарно), ГЛ+Г; глистењак + екстракт глистењака (фолијарно), ГЛ+ЕГ; компост из производње печурака, К; компост из производње печурака + гуано (фолијарно), К+Г; компост из производње печурака + екстракт глистењака, К+ЕГ; гуано (фертигација + фолијарно), Г; екстракт глистењака (фертигација + фолијарно), ЕГ; стандардни програм ђубрења са минералним NPK ђубривима, NPK). У узорцима земљишта одређен је садржај минералних облика N, приступачних облика P, K, Ca, Mg, Fe, Mn, Cu, Zn и pH вредност земљишта. Поред параметара приноса јагоде (број цветова, прој плодова, просечна маса плода) у све три године плодоношења одређени су садржај макро и микроелемената у листу и плоду јагоде, и параметри квалитета плода јагоде (укупан садржај растворљиве суве материје, укупан садржај киселина, садржај укупних антоцијана, антиоксидативна активност, обојеност и чврстина плода). Резултати истраживања су показали да се продужено дејство примене чврстих и течних органских ђубрива на садржај хранљивих елемената у земљишту значајно разликује у зависности од елемента који се посматра. Примена чврстих органских ђубрива имала је највећи утицај на садржај приступачних облика фосфора, затим калијума, док је најмањи утицај имала на садржај минералних облика азота у земљишту. Изузев стајњака, примена органских ђубрива, у количини еквивалентној 170 kg N ha-1, није имала утицај на концентрацију приступачних облика секундарних макроелемената и микроелемената у земљишту. Земљиште покривено црном ПЕ фолијом одликовало се вишим садржајем минералних облика азота и приступачних облика Fe, Mn, Zn и Cu у односу на земљиште покривено сламом, у свим терминима мерења. Примена чврстих органских ђубрива приликом садње јагоде довела је до значајног повећања приноса, у односу на контролу, само у првој години плодоношења, док је у другој и трећој години плодоношења највиши принос јагоде остварен на третманима где су примењена NPK ђубрива и течни гуано. Третмани ђубрења имали су значајан утицај на минерални састав, садржај растворљиве суве материје, садржај киселина, садржај антоцијана, антиоксидативну активност и обојеност плода. Примена црне полиетиленске фолије, поред позитивног утицаја на садржај хранљивих елемената у земљишту, довела је до вишег приноса и квалитета плода јагоде у односу на примену сламе као малча. Rезултати показују да се применом црне фолије може значајно повећати ефикасност ђубрива чиме се смањује ризик од загађења животне средине и остварује већа економска добит у производњи јагоде.<br>Organska đubriva sadrže gotovo sve neophodne hranljive elemente za gajene biljke, ali imaju značajno manju efikasnost od sintetičkih đubriva jer je sadržaj hraniva neuporedivo niži u odnosu na sintetička, a oblici u kojima se nalaze nisu direktno pristupačni gajenim biljkama. Cilj istraživanja bio je da se ispita uticaj primene različitih organskih đubriva biljnog i životinjskog porekla, kao i tečnih đubriva na hemijska svojstva zemljišta, prinos i kvalitet jagode u okviru dva sistema proizvodnje (malčiranja zemljišta). Poljski ogled je postavljen kao dvofaktorijalni po metodi/planu podeljenih parcela (Split/plot), sa slučajnim rasporedom tretmana. Ogled se sastojao od dve glavne parcele na kojima je ispitan uticaj dva različita načina pokrivanja zemljišta (malč od slame i crna polietilenska folija), dok je na osnovnim parcelama ispitan uticaj 13 različitih tretmana đubrenja (kontrola &ndash; bez primene đubriva, &Oslash;; goveđi stajnjak, S; goveđi stajnjak + guano (folijarno), S+G; goveđi stajnjak + ekstakt glistenjaka (folijarno), S+EG; glistenjak, GL; glistenjak + guano (folijarno), GL+G; glistenjak + ekstrakt glistenjaka (folijarno), GL+EG; kompost iz proizvodnje pečuraka, K; kompost iz proizvodnje pečuraka + guano (folijarno), K+G; kompost iz proizvodnje pečuraka + ekstrakt glistenjaka, K+EG; guano (fertigacija + folijarno), G; ekstrakt glistenjaka (fertigacija + folijarno), EG; standardni program đubrenja sa mineralnim NPK đubrivima, NPK). U uzorcima zemljišta određen je sadržaj mineralnih oblika N, pristupačnih oblika P, K, Ca, Mg, Fe, Mn, Cu, Zn i pH vrednost zemljišta. Pored parametara prinosa jagode (broj cvetova, proj plodova, prosečna masa ploda) u sve tri godine plodonošenja određeni su sadržaj makro i mikroelemenata u listu i plodu jagode, i parametri kvaliteta ploda jagode (ukupan sadržaj rastvorljive suve materije, ukupan sadržaj kiselina, sadržaj ukupnih antocijana, antioksidativna aktivnost, obojenost i čvrstina ploda). Rezultati istraživanja su pokazali da se produženo dejstvo primene čvrstih i tečnih organskih đubriva na sadržaj hranljivih elemenata u zemljištu značajno razlikuje u zavisnosti od elementa koji se posmatra. Primena čvrstih organskih đubriva imala je najveći uticaj na sadržaj pristupačnih oblika fosfora, zatim kalijuma, dok je najmanji uticaj imala na sadržaj mineralnih oblika azota u zemljištu. Izuzev stajnjaka, primena organskih đubriva, u količini ekvivalentnoj 170 kg N ha-1, nije imala uticaj na koncentraciju pristupačnih oblika sekundarnih makroelemenata i mikroelemenata u zemljištu. Zemljište pokriveno crnom PE folijom odlikovalo se višim sadržajem mineralnih oblika azota i pristupačnih oblika Fe, Mn, Zn i Cu u odnosu na zemljište pokriveno slamom, u svim terminima merenja. Primena čvrstih organskih đubriva prilikom sadnje jagode dovela je do značajnog povećanja prinosa, u odnosu na kontrolu, samo u prvoj godini plodonošenja, dok je u drugoj i trećoj godini plodonošenja najviši prinos jagode ostvaren na tretmanima gde su primenjena NPK đubriva i tečni guano. Tretmani đubrenja imali su značajan uticaj na mineralni sastav, sadržaj rastvorljive suve materije, sadržaj kiselina, sadržaj antocijana, antioksidativnu aktivnost i obojenost ploda. Primena crne polietilenske folije, pored pozitivnog uticaja na sadržaj hranljivih elemenata u zemljištu, dovela je do višeg prinosa i kvaliteta ploda jagode u odnosu na primenu slame kao malča. Rezultati pokazuju da se primenom crne folije može značajno povećati efikasnost đubriva čime se smanjuje rizik od zagađenja životne sredine i ostvaruje veća ekonomska dobit u proizvodnji jagode.<br>Organic fertilizers contain almost all the necessary nutritional elements for cultivated plants, but they have a significantly lower efficiency compared to synthetic fertilizers due to lower nutrient content and the forms of nutrients in which they are not directly accessible to the cultivated plants. The aim of this study was to quantify the effect of the application of different plant and animal origin organic fertilizer, as well as liquid fertilizers, on soil chemical properties, yield and quality of strawberries in two production systems (soil mulching). The field experiment was conducted using a 2-factorial split-plot completely randomized design, with ground cover management (mulch) as main-plot factor and fertilization treatments in sub-plot. On the main plots we examined the influence of two different mulches (straw and black polyethylene sheet), while on sub-plots the effect of 13 different treatments of fertilization was examined (control - no fertilization, &Oslash;; dairy manure, С; dairy manure + guano (foliar application), С+Г; dairy manure + vermicompost leachate (foliar application), С+ЕГ; vermicompost, ГЛ; vermicompost leachate + guano (foliar application), ГЛ+Г; vermicompost + vermicompost leachate (foliar application), ГЛ+ЕГ; spent mushroom compost, К; spent mushroom compost + guano (foliar application), К+Г; spent mushroom compost + vermicompost leachate, К+ЕГ; guano (fertigation + foliar application), Г; vermicompost leachate (fertigation + foliar application), ЕГ; standard fertilization with mineral NPK fertilizers, NPK). The soil samples were analysed to determine the content of mineral forms of N, available forms of P, K, Ca, Mg, Fe, Mn, Cu, Zn and soil pH value. Beside parameters of strawberry yield (number of flowers, number of fruits, average fruit weight) in all three fruiting years we determined the content of macro- and microelements in the leaves and fruits, as well as fruit quality parameters (total soluble solids, total acidity, total anthocyanins, antioxidant activity, coloring and fruit firmness). The results showed that application of solid and liquid organic fertilizers had a different residual effect on concentration of macro- and micro elements in the soil. Application of solid organic fertilizer had the greatest influence on the content of available forms of phosphorus, than potassium, while the least impact had on the content of mineral forms of nitrogen in the soil. Except for dairy manure, the application of organic fertilizers, in amount equivalent to 170 kg N ha-1, had no effect on concentration of available forms of secondary macroelements and microelements in the soil. Soil covered with black polyethylene mulch had higher content of mineral forms of nitrogen and available forms of Fe, Mn, Zn and Cu, compared to soil covered with straw mulch, in all terms of measuring. The application of solid organic fertilizers led to a significant increase in yield compared to the control in the first fruiting year, while in the second and third fruiting years the highest yields were achieved on the treatments where NPK fertilizer and liquid guano were applied. Fertilization treatments had a significant effect on the mineral composition, content of soluble solids, titrible acidity, content of anthocyanins, antioxidant activity and color of the strawberry fruits. Black polyethylene mulch had positive impact on concentration of macro- and microelements in soil and led to higher yield and quality of strawberry fruits compared to straw mulch. The results shows that the black polyethylene mulch can significantly increase fertilizer efficiency, which reduce the risk of environmental pollution and may result in greater economic gain in strawberry production.

O manejo dos resíduos florestais (serapilheira e sobras da colheita) já foi amplamente discutido na década de 90, época em que técnicas de preparo de solo baseadas no cultivo mínimo foram adotadas na formação de povoamentos florestais no Brasil. Atualmente esse tema volta a ser discutido, isso porque pressões quanto à utilização dos resíduos florestais como fonte de energia tem surgido. Devido a esse fato, compreender os efeitos da remoção dos resíduos florestais e da fertilização em sucessivas rotações se torna necessário, isso para que manejos inadequados não comprometam a sustentabilidade da produção florestal. O objetivo geral com essa tese foi compreender os impactos da remoção dos resíduos florestais e da não fertilização, por sucessivas rotações, na qualidade do solo, crescimento, ciclagem de nutrientes e consequentemente na sustentabilidade da produção de florestas de eucalipto. Este estudo foi conduzido na Estação Experimental de Ciências Florestais de Itatinga - SP, ESALQ - USP. O experimento foi instalado em 2004, com diferentes intensidades de remoção dos resíduos florestais e omissão de N, P, K, Ca e Mg. Na primeira rotação de cultivo, o experimento foi conduzido por oito anos. Em 2012, o experimento foi reinstalado, reaplicando todos os tratamentos. Os resultados foram divididos em cinco capítulos. Com o primeiro objetivou-se avaliar o efeito dos tratamentos no crescimento e na relação entre resposta à fertilização e variáveis climáticas. Observou-se que a remoção dos resíduos florestais reduziu em 5% o volume final de madeira (8 anos de idade) da primeira rotação, entretanto essa diferença não foi significativa. Aos 4 anos da segunda rotação, a remoção dos resíduos florestais resultou em redução de 14 % no volume de madeira com casca (p=0,001). Esta redução no volume de madeira com a remoção dos resíduos por duas rotações consecutivas, mesmo com alto invertimento em fertilização, mostra que outros efeitos além da disponibilidade de nutrientes estão impactando a produtividade. Desta forma, procurou-se entender quais seriam esses efeitos. Observou-se (segundo capítulo) que a remoção dos resíduos florestais reduziu em 25 % o teor de C da camada superficial do solo, com isso, reduziu a atividade microbiológica e aumentou a disponibilidade de Al. Além disso, com a remoção dos resíduos florestais observou-se redução nos estoques de C, N, P e S do solo (terceiro capítulo). Com o fracionamento do P do solo (quarto capítulo), observou-se que a remoção dos resíduos florestais resultou na redução de 34 para 30 % a contribuição das frações lábeis e moderadamente lábeis no P total e redução de 40 % (p = 0,014) da fração lábil. No último capítulo avaliou-se o efeito da fertilização na produtividade primária líquida (PPL) e na ciclagem de nutrientes. A não fertilização com P reduziu em 10 % a PPL, entretanto não afetou sua partição. A não fertilização com K reduziu em 63% a PPL e reduziu a partição desta alocada no lenho. A não fertilização com K também aumentou a produção de serapilheira e reduziu a taxa de retranslocação de todos os demais nutrientes. A não fertilização com N e P aumentou a taxa de retranslocação desses nutrientes e reduziu a taxa de decomposição da serapilheira. Estes resultados indicam que a remoção total dos resíduos florestais e/ou a não fertilização comprometem a sustentabilidade da produção florestal, sendo este efeito observado na primeira, ou no máximo na segunda rotação.<br>The forest residue management was highly studied in 90\'s yeas, when the minimal tillage was consolidated as the main technique to forest plantation in Brazil. Currently this issue has been discussed again. This because pressure to use of these forest residues as energy source has emerged. Due this fact is necessary a better comprehension of the effect of the forest residue removal and fertilizer application on the wood production sustainability. The main goal with this thesis was to understand the impact of the forest residue removal and the absence of fertilizer application, over two crop rotation, on the soil quality, tree growth, nutrient cycling and consequently on the wood production sustainability. The study was carried out at the Itatinga Forest Science Experimental Station of the ESALQ-USP. The experimental site was settled in 2004, with different timber harvest residues intensity and absence of fertilizer application with N, P, K, Ca and Mg. This plantation was conducted over 8 years (R1), and then, in 2012, it was reestablished (R2), reapplying all the treatments on the same plots. The results of this experiment were splitted out in 5 chapters. With the first one, our goal was to assess the effect of the treatments on the tree growth and to understand the effect of weather condition on the treatment\'s response. The forest residual removal reduced in 5 % the wood volume at 8 years of the R1. At 4 years old of the R2, the forest residue removal decreased 14 % the wood volume (p=0,001). This reduction in the wood volume even with fertilizer application indicated that another effect beyond the nutrient availability can impact the wood productivity. This way these effects were studied and had been showed in the follow chapters. In the chapter 2 we found that the forest residue removal reduced 25 % the soil organic carbon (SOC) in the top layer, this way reducing the microbial activity and increasing the Al availability. Beyond that, the forest residue removal reduced the soil C, N, P and S stocks over 1 m deep (Chapter 3). With the P fractionation (Chapter 4) a reduction of 40% in the labile P fraction was discovered. In the last chapter we assessed the effect of the fertilizer application on the net primary production (NPP) and on the nutrient cycling. The absence of P fertilizer reduced in 10 % the NPP, however did not affect in this partition. The absence of K fertilizer reduced in 63 % the NPP and reduced the allocation in the wood. The absence of K fertilizer also improved the litterfall production and reduced the nutrient retranslocation rate. The absence of N and P fertilizer application improved the retranslocation rate of these nutrients and reduced the litter layer decomposition rate.

Le statut organique d'un sol ferrugineux tropical peu lessivé de texture sableuse de la zone Centre-Nord du Sénégal a été étudié sur deux dispositifs de longue durée. Le labour, l'apport de fumier et diverses successions culturales ont induit une différenciation dans la productivité du sol. On a tenté d'expliquer les mécanismes d'évolution de la matière organique du sol et du cycle interne de l'azote et d'en tirer les conséquences agronomiques; notamment, on a suivi à l'aide du 15N le devenir in situ d'un fertilisant azote. Le coefficient réel d'utilisation de l'azote engrais par une culture de mil est particulièrement faible (10 à 17%); par contre l'immobilisation de cet azote engrais dans le sol à la récolte atteint selon les traitements 44 à 80% de l'apport. Ce fait est à rapprocher de l'importante augmentation de la biomasse microbienne observée en fin de période pluvieuse. Le fractionnement des composés organiques azotés par hydrolyse acide a montré que les pratiques culturales telles que le labour; la rotation arachide-mil et surtout l'apport de fumier augmentent de façon significative la teneur en azote alpha-amine du sol; cet azote contribue fortement au pool d'azote mobilisable par les cultures. Ces phénomènes soulignent la capacité du sol à mettre en réserve l'azote avant la saison sèche mais aussi la difficulté à gérer la fertilité azotée de ces terres: il est indispensable d'optimiser la biodisponibilité de cet azote reminéralisé pour minimiser les pertes d'azote nitrique par lixiviation afin d'éviter un accroissement de l'acidification

Ziel der Arbeit ist die Gesamtbilanzierung der Treibhausgasemissionen eines Anbausystems unter Bewässerung auf einem Sandboden. Die dazu aufgestellte Treibhausgasbilanz basiert auf langjährigen Datenreihen zu Erträgen und Corg-Vorräten eines Dauerfeldversuchs sowie auf zweijährigen im Feldversuch durchgeführten N2O-Messungen. Die durchgeführten Untersuchungen zum Einfluss der Bewässerung auf die Corg-Vorräte zeigen, dass der Einsatz von mineralischem Stickstoffdünger und Bewässerung auf einem leichten Standort unter den klimatischen Bedingungen Nord-Ost-Deutschlands positive Effekte hat. Die N2O-Emissionen eines Sandbodens unter den klimatischen Bedingungen Brandenburgs sind sehr niedrig. Die Applikation von mineralischem Stickstoffdünger hat nur schwache und Bewässerung hat aufgrund der der hohen Bodendurchlüftung des Sandbodens keine Effekte auf die Höhe der N2O-Emissionen. Die direkten und indirekten Emissionen aus dem Maschinen- und Betriebsmitteleinsatz erhöhen sich bei Bewässerung und steigender Stickstoffdüngung deutlich. Bei den indirekten Treibhausgasemissionen nehmen die Emissionen der Herstellung des mineralischen Stickstoffdüngers einen bedeutenden Anteil der Gesamttreibhausgasemissionen ein. Bewässerung führt durch den erhöhten Dieselverbrauch hauptsächlich zu einer Erhöhung der direkten Emissionen. Unter Bewässerung kann jedoch ein Teil der Emissionen durch zunehmende Corg-Vorräte kompensiert werden. Somit sind in einigen Fällen die Gesamttreibhausgasemissionen pro Hektar bei Bewässerung geringer als ohne Bewässerung. Die aus Stickstoffdüngung und Bewässerung resultierenden Ertragserhöhungen führen dazu, dass die Gesamttreibhausgasemissionen bezogen auf die Ertragseinheit in den meisten bewässerten Varianten deutlich geringer sind als in den unbewässerten. Daraus lässt sich ableiten, dass Bewässerung auf einem Sandboden zu einer Verminderung der Treibhausgasemissionen beitragen kann.<br>The aim of this work is the estimation of the net greenhouse gas emissions by a greenhouse balance for an irrigated cropping system on a sandy soil in north-east Germany under various nitrogen fertilizer intensities. The balances are based on data of yields and SOC stocks of an irrigated long term field experiment as well as on results of N2O-measurements over two years. The results of the analysis of the long term response of irrigation and nitrogen fertilization have shown that irrigation and mineral nitrogen fertilization led to significant increases in yields and harvest residues. The increased carbon inputs from above ground harvest residues had positive effects on the SOC stocks. The results of N2O measurements indicated that N2O emissions from a sandy soil are very low. Mineral nitrogen fertilization had only marginal effects. Irrigation showed no effects on the amount of N2O emissions. On the one hand the analysis of the prepared greenhouse gas balances showed that irrigation and increased nitrogen fertilization lead to a strong increase of direct and indirect emissions from machinery and maintenance resource use. The indirect emissions of nitrogen fertilizer production took up a main part of the net greenhouse gas emissions. Irrigation mainly increased greenhouse gas emissions of fuel use and fuel production as well as the emissions of the machinery production. On the other hand the increasing SOC stocks especially in the fertilized variants under irrigation led to a compensation of a huge part of the additional emissions. Thus, in many cases the net greenhouse gas emissions per unit area was lower under irrigation. Due to the increased yields under irrigation the net greenhouse gas emissions per unit yield were lower than that under non-irrigated conditions.