Littérature scientifique sur le sujet « Soils and nutrition »
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Articles de revues sur le sujet "Soils and nutrition"
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Naidu, R., et P. Rengasamy. « Ion interactions and constraints to plant nutrition in Australian sodic soils ». Soil Research 31, no 6 (1993) : 801. http://dx.doi.org/10.1071/sr9930801.
Texte intégralRésumé :
Many of the arable soils in Australia are affected by salinity and/or sodicity. Nutrient deficiency and ion toxicity may occur in both saline and sodic soils. Ho-ever, the mechanism for these constraints on plant growth in sodic soils differs from that of saline soils. Fertility of sodic soils with low nutrient reserves is compounded by the low supply of water and oxygen to roots in profiles with dispersive clays. Nutrient constraints in sodic soils are created by the electron and proton activities (pE and pH) in an environment of degraded soil structure. Australian sodic soils accumulate relatively low levels of organic matter. High sodium, high pH and low biological activity, commonly found in these soils, are not conducive for both the accumulation of organic matter and its mineralization. As a result, these soils are deficient in N and S. Australian soils are highly weathered and have moderate to low reserves of many plant nutrients such as Cu, Mn, Mo, Zn and P. Solubility of phosphorus is generally increased in sodic soils. Poor leaching conditions accumulate boron in soil layers. Higher concentrations of sodium than of calcium in these soils are the major cause of both physical and nutritional problems. Therefore, amelioration of sodicity is the logical first step in improving the chemical fertility of sodic soils. However, fertilizer application and improvement of soil organic matter are essential to increase yields to match the potential yield predictable from climate.
2
Broschat, Timothy K. « Palm Nutrition and Fertilization ». HortTechnology 19, no 4 (janvier 2009) : 690–94. http://dx.doi.org/10.21273/hortsci.19.4.690.
Texte intégralRésumé :
Palms (Arecaceae) growing in containers have similar nutritional requirements as other tropical ornamental plants and grow well with fertilizers having an elemental ratio of 3N:0.4P:1.7K. However, palms growing in the landscape or field nurseries have very different nutritional requirements from dicotyledonous plants. Whereas nitrogen (N) is the primary limiting nutrient element in container production, potassium (K), manganese (Mn), magnesium (Mg), boron (B), and iron (Fe) deficiencies are more widespread than N deficiency in most landscape soils. Because palms have a single apical meristem, deficiencies of K, Mn, or B can be fatal. In addition to insufficient nutrients in the soil, palm nutrient deficiencies can be caused by high soil pH, certain types of organic matter, deep planting, poor soil aeration, cold soil temperatures, and nutrient imbalances. Correction of nutritional deficiencies in palms can take up to 2 years or longer and therefore prevention of deficiencies by proper fertilization is important. Research has shown that high N:K ratio fertilizers applied directly, or indirectly via application to adjacent turfgrass in a landscape, can exacerbate K and Mg deficiencies in palms, sometimes fatally. For sandy Atlantic coastal plain soils in the southeastern United States, an analysis of 8N–0.9P–10K–4Mg plus micronutrients has been recommended.
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Rochester, Ian J. « Phosphorus and potassium nutrition of cotton : interaction with sodium ». Crop and Pasture Science 61, no 10 (2010) : 825. http://dx.doi.org/10.1071/cp10043.
Texte intégralRésumé :
Poor phosphorus (P) and potassium (K) nutrition limits the growth and yield of many cotton (Gossypium hirsutum L.) crops in Australia. The demand for nutrients from cotton crops has risen as yields have increased over the past 40 years, and some soils have become depleted in these nutrients. Cotton is commonly grown on sodic soils that are more prone to nutritional problems. A survey of thirty-one sites over four years in northern NSW, Australia included twelve sites that had sodic topsoil. However, available soil P and K at all sites were above established critical values for cotton crops. Soil sodicity was negatively correlated with available soil P and K, and positively with soil salinity and chloride. Cotton leaf P and K concentrations at flowering were negatively correlated with leaf sodium (Na) concentration. The cotton crops growing in sodic soils produced 20% less dry matter (3 weeks before crop defoliation) and crop P and K uptake was reduced by 23% and 25%, respectively, whereas Na uptake was 107% higher. High soil sodicity also reduced the uptake of micro-nutrients. Two field experiments in adjacent sodic and non-sodic areas on one farm showed a yield response to P fertiliser application at the non-sodic site only, but where soil P availability was above the accepted critical value. Application of K fertiliser did not increase crop K uptake or yield. The lower yield and poorer growth of irrigated cotton on sodic soils was related to higher Na uptake and lower P and K uptake, possibly due to restricted root growth in sodic soils.
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KARAMANOS, R. E., J. G. FRADETTE et P. D. GERWING. « EVALUATION OF COPPER AND MANGANESE NUTRITION OF SPRING WHEAT GROWN ON ORGANIC SOILS ». Canadian Journal of Soil Science 65, no 1 (1 février 1985) : 133–48. http://dx.doi.org/10.4141/cjss85-014.
Texte intégralRésumé :
A growth chamber experiment with six organic soils was conducted to assess the Cu and Mn nutrition of spring wheat grown on organic soils. Three rates of Cu (0, 5, and 10 μg∙g−1 of equivalent volume of a fsl) and three rates on Mn (0, 25, and 50 μg∙g−1 of equivalent volume of a fsl) were applied in all combinations to spring wheat grown on six organic soils. Normal growth of wheat plants was achieved only in soils and treatments where a proper balance on Mn and Cu was achieved. Dry matter yield responses at 45, and 60 days and grain yields reflected the significance of this balance. The major conclusion from this study is that normal wheat growth was achieved on organic soils only when the DTPA-extractable soil (soil: extractant ratio of 1:5) Mn/Cu ratio was between 1–15. At Mn/Cu ratio below 1 and above 15, yield reducion and death of plants occurred due to Mn and Cu deficiency, respectively. Key words: Organic soils, spring wheat, available soil Mn and Cu, Mn/Cu interaction, Mn/Cu ratio
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Chowdhury, Nasrin, et Md Mamunur Rasid. « Assessment of Soil Fertility and Crop Nutrient Status in Agricultural Soils Near a Brick Kiln Cluster ». Journal of Agricultural Science 13, no 1 (15 décembre 2020) : 122. http://dx.doi.org/10.5539/jas.v13n1p122.
Texte intégralRésumé :
Brick kiln exhaust when deposited can hamper the nutritional status of the agricultural soils and crops. To study the impact, soil and associated plant samples were collected from the vicinity of a brick kiln cluster in Chattogram, Bangladesh. The soil contamination was evaluated by heavy metal indices. Agricultural soils close to the brick kiln area were very strongly acid to slightly acid. Organic carbon, total nitrogen and available phosphorus content of the agriculture soils near brick kiln cluster were 0.35% to 1.01%, 0.10 to 0.24% and 2.21 to 13.48 mg kg-1 respectively and the significant different mean value of 0.70%, 0.22% and 14.65 mg kg-1 respectively in the reference soil. The nutritional status of sampling sites was lower than the previously reported data. The nutrition status of the plants was at an optimum level as regular fertilizer application was practiced but showed an irregular pattern along with all the soil parameters and heavy metal indices. The contamination factor (Cd), potential ecological risk index (PER) and geo-accumulation index (Igeo) demonstrated that the agricultural soils in the vicinity of the brick kiln cluster were moderately- to highly-polluted. This indicates the deterioration of soil quality by uncontrolled brick kiln operation.
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Mariano, Isabela Orlando dos Santos, Luiz Arnaldo Fernandes, Valdemar Faquin et Alex Teixeira de Andrade. « Phosphorus critical levels and availability in lowland soils cultivated with flooded rice ». Scientia Agricola 59, no 1 (mars 2002) : 113–20. http://dx.doi.org/10.1590/s0103-90162002000100017.
Texte intégralRésumé :
Lowland soils present a great potential for the flooded rice crop. This work aimed to estimate critical levels of P in waterlogged soils cultivated with rice using Mehlich 1 and anion exchange resin as soil-P extractors, compare the performance of these extractors as for the evaluation of the P availability, and study the soil-P fractions involved in the P nutrition of the rice crop. Studied soils consisted of four Histosols: Low Humic Gley (GP), Aluvial (A), Humic Gley (GH) and Bog Soil (O) which were previously cultivated with beans. The experimental design was completely randomized, in a factorial scheme, using four soils, five P rates (75, 150, 300, 500 and 800 mg dm-3) and two liming treatments (with and without liming), with three replicates. After 60 days of flooding, soil samples were submitted to P extraction by Mehlich 1 and resin, and phosphorous fractionation. Two rice plants were cultivated in pots containing 3 dm³ of waterlogged soils. The labile P and the moderately labile P of the soils contributed for rice nutrition. The two tested extractors presented efficiency in the evaluation of P availability for the rice cultivated in lowland waterlogged soils.
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Mamadalieva, Saidakhon Bakhodirbekovna, et Zuhriddin Muminovich Jumaboev. « Agricultural Measures In Soil Effect On Nutrition ». American Journal of Applied sciences 02, no 12 (12 décembre 2020) : 7–12. http://dx.doi.org/10.37547/tajas/volume02issue12-02.
Texte intégralRésumé :
Results of scientific substantiation and introduction of optimal nutritional norms,seedling thickness and water consumption in the production of fairy-tale, high- quality cotton crop of UzPITI-201 cotton cultivated in the technology of sowing seeds under the film, which is a key element of accelerated saving technologies in light gray soils of Andijan region listed.
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Prietzel, Jörg, Jaane Krüger, Klaus Kaiser, Wulf Amelung, Sara L. Bauke, Michaela A. Dippold, Ellen Kandeler et al. « Soil phosphorus status and P nutrition strategies of European beech forests on carbonate compared to silicate parent material ». Biogeochemistry 158, no 1 (février 2022) : 39–72. http://dx.doi.org/10.1007/s10533-021-00884-7.
Texte intégralRésumé :
AbstractSustainable forest management requires understanding of ecosystem phosphorus (P) cycling. Lang et al. (2017) [Biogeochemistry,https://doi.org/10.1007/s10533-017-0375-0] introduced the concept of P-acquiring vs. P-recycling nutrition strategies for European beech (Fagus sylvatica L.) forests on silicate parent material, and demonstrated a change from P-acquiring to P-recycling nutrition from P-rich to P-poor sites. The present study extends this silicate rock-based assessment to forest sites with soils formed from carbonate bedrock. For all sites, it presents a large set of general soil and bedrock chemistry data. It thoroughly describes the soil P status and generates a comprehensive concept on forest ecosystem P nutrition covering the majority of Central European forest soils. For this purpose, an Ecosystem P Nutrition Index (ENIP) was developed, which enabled the comparison of forest P nutrition strategies at the carbonate sites in our study among each other and also with those of the silicate sites investigated by Lang et al. (2017). The P status of forest soils on carbonate substrates was characterized by low soil P stocks and a large fraction of organic Ca-bound P (probably largely Ca phytate) during early stages of pedogenesis. Soil P stocks, particularly those in the mineral soil and of inorganic P forms, including Al- and Fe-bound P, became more abundant with progressing pedogenesis and accumulation of carbonate rock dissolution residue. Phosphorus-rich impure, silicate-enriched carbonate bedrock promoted the accumulation of dissolution residue and supported larger soil P stocks, mainly bound to Fe and Al minerals. In carbonate-derived soils, only low P amounts were bioavailable during early stages of pedogenesis, and, similar to P-poor silicate sites, P nutrition of beech forests depended on tight (re)cycling of P bound in forest floor soil organic matter (SOM). In contrast to P-poor silicate sites, where the ecosystem P nutrition strategy is direct biotic recycling of SOM-bound organic P, recycling during early stages of pedogenesis on carbonate substrates also involves the dissolution of stable Ca-Porg precipitates formed from phosphate released during SOM decomposition. In contrast to silicate sites, progressing pedogenesis and accumulation of P-enriched carbonate bedrock dissolution residue at the carbonate sites promote again P-acquiring mechanisms for ecosystem P nutrition.
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Negreanu-Pirjol, Bogdan-Stefan, Ticuta Negreanu-Pirjol et Gabriela Mihaela Paraschiv. « Residual Marine Algae Biomass - An Important Raw Material for Obtaining a Soil Biostimulator-Regenerator ». European Journal of Medicine and Natural Sciences 2, no 2 (15 octobre 2019) : 37. http://dx.doi.org/10.26417/749ztk83f.
Texte intégralRésumé :
This paper highlight a study regarding the valorification of residual marine algae biomass along Romanian Black Sea Coast, which recorded in the last summer period an accumulation of a large seaweed biomass quantities. The valorization of this waste was conceived as a result of theirs nutritional potential for improvind degraded soils of Dobrudja region, Romania and as complex capitalization of this biomass. It was establish the biotechnological process for the new biosolid nutrient composite obtaining. The parameter physical-chemical results of raw material used for biofertilizer obtaining, emphasized an increased organic charge compared with the inorganic compounds. Also, an increased value of total organic nitrogen and an optimum pH limits, was registered. Regarding the nutrients concentrations values, it could be noticed that the new biosolid fertilizer contains organic matter and valuable nutritive elements (N, P) could be contributed to the enhancement of the soil quality. The new biosolid biostimulator-regenerator obtained from natural residues bring a complex of nutrients for degraded soils by the presence of organic residual compounds, through the proteins, lipids, nutrients (nitrogen, phosphorus) and mineral salts content, necessary for plants nutrition and improvement of soils quality.
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Wacal, Cosmas, Naoki Ogata, Daniel Basalirwa, Daisuke Sasagawa, Tsugiyuki Masunaga, Sadahiro Yamamoto et Eiji Nishihara. « Growth and K Nutrition of Sesame (Sesamum indicum L.) Seedlings as Affected by Balancing Soil Exchangeable Cations Ca, Mg, and K of Continuously Monocropped Soil from Upland Fields Converted Paddy ». Agronomy 9, no 12 (29 novembre 2019) : 819. http://dx.doi.org/10.3390/agronomy9120819.
Texte intégralRésumé :
Growth of sesame is known to be limited by poor K nutrition as a result of imbalance in soil exchangeable cations that cause a competitive ion effect in continuous monocropping from upland fields converted paddy. We hypothesized that balancing soil exchangeable cations will improve the K nutrition and growth of sesame plants. Therefore, the specific objectives of this study were to determine the effect of balancing soil exchangeable cations Ca, Mg, and K of continuously monocropped soils on the growth and cation uptake of sesame seedlings and also identify a suitable source of nutrients for improving K nutrition. A pot experiment was conducted under greenhouse condition in a 3 × 3 factorial design consisting of three levels of balancing treatments i.e. inorganic fertilizer for Ca, Mg, and K, rice husk biochar to increase K content, and the three durations of continuous monocropping soils of one year, two years, and four years from upland fields converted paddy. Balancing soil exchangeable cations was aimed at achieving optimal base saturations (CaO, 75%; MgO, 25%; and K2O, 10%). Results showed that balancing exchangeable cations did not significantly affect growth and cation uptake in the one and two-year soils but significant effect was observed in the four-year soil. Overall, plant height and dry weight increased for the balancing treatments of inorganic fertilizer K and rice husk biochar. Balancing exchangeable cations with biochar was more beneficial than with inorganic fertilizers. The four-year soil’s growth increase was attributed to an increase in K concentration and uptake due to the decrease in the soil Ca/K and Mg/K ratios to that of acceptable levels, which eliminated competitive ion effect as the soil K saturation increased above 5.0%, enhancing sesame growth. Therefore, a balanced soil exchangeable Ca, Mg, and K that eliminates a competitive ion effect will improve sesame growth and K nutrition although future research should focus on ensuring balanced cation rations under field conditions in continuous monocropping.
Thèses sur le sujet "Soils and nutrition"
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Coyle, Kieran. « An investigation of the role of soil micro-organisms in phosphorus mobilisation : a report submitted to fulfil the requrements of the degree of Doctor of Philosophy ». Title page, table of contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phc8814.pdf.
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Kim, Hak Jin. « Ion-selective electrodes for simultaneous real-time analysis for soil macronutrients ». Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4471.
Texte intégralRésumé :
Thesis (Ph.D.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (April 26, 2007) Vita. Includes bibliographical references.
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PFEIFFER, CHARLES MICHAEL. « GROWTH AND NUTRITION OF MYCORRHIZAL GUAYULE IN SALINE SOILS (ENDOMYCORRHIZAE, GLOMUS INTRARADICES, SALINITY) ». Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183780.
Texte intégralRésumé :
Inoculation of Parthenium argentatum (guayule) with an endomycorrhizal fungus (Glomus intraradices) increased the growth of guayule in saline and non-saline soils low in available phosphorus. Addition of 100 ug/g of P as Ca(H2PO4)2 to soils low in available phosphorus was as efficient as G. intraradices in stimulating the growth of guayule. The concentrations and total plant accumulations of minerals within guayule shoots varied depending on growth of the plants and the minerals assayed. In most cases, the concentrations of Cu, Zn, Mn, Na and Cl increased in the shoot tissues of guayule grown in soils which contained added NaCl. Generally, addition of phosphorus to the soil resulted in decreased concentrations of Cu and Zn and increased concentrations of PO4 in guayule shoots. The total accumulations of minerals by guayule was directly influenced by the biomass of plants. Increased biomass of plants generally resulted in increased total accumulations of the minerals assayed. The influence of mycorrhizae on the accumulations of minerals by guayule grown in a saline soil was evaluated by comparing nonmycorrhizal plants with the same biomass and phosphorus nutrition as mycorrhizal plants. Mycorrhizae increased the concentrations and total plant accumulations of Zn and decreased the content of Cl within guayule shoots. Colonization of guayule roots by G. intraradices was not affected by addition of P to the soil. Addition of NaCl to the soil decreased the formation of arbuscules and vesicles within roots and increased the incidence in which no fungal structures were seen. The combination of P and NaCl added to soil had a synergistic effect on the mycorrhizae of guayule. Addition of both P and NaCl to soil reduced the occurrence of hyphae, arbuscules and vesicles within roots and decreased the overall infection of guayule roots by G. intraradices.
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Cruz, David Ricardo Jimenez. « Influence of soils, nutrition, and water relations upon charcoal rot disease processes in Kansas ». Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/10747.
Texte intégralRésumé :
Master of ScienceDepartment of Plant Pathology
Christopher R. Little
Christopher R. Little
Charcoal rot, caused by Macrophomina phaseolina, is the most important soybean disease in Kansas. Several strategies have been recommended to control this disease including crop rotation, lower plant densities, biological control, plant resistance and tolerance, and fungicide application. However, those techniques have not been completely effective and the information concerning soil texture, irrigation and micronutrient fertility (particularly manganese) upon charcoal rot disease severity and the pathogen population is limited. The objective of this study was to determine key factors that affect the biology of M. phaseolina and charcoal rot processes under laboratory, greenhouse and field conditions. M. phaseolina microsclerotia were produced from PDA pure isolate and infested Japanese millet in the laboratory and characterized by different techniques such as serial dilutions in semi selective media with the aim to produce quality inoculum to reliably infect soybean seedling roots under greenhouse conditions; production of inoculum by infesting Japanese millet was the most efficient method. Root colonization and root infection of soybean seedlings was assessed through the use of M. phaseolina inoculum under controlled conditions in the greenhouse. Root infection by M. phaseolina and microsclerotia longevity in soil is determined by environmental factors such as soil moisture content, soil texture and source of inoculum. The objective of the greenhouse study was to determine the impact of these variables on seedling root infection at the V1 and V2 development stages. Artificial soils with different textures were infested; M. phaseolina microsclerotia and soybean seedlings were exposed to different soil moisture contents including pot saturation, pot (field) capacity, and permanent wilting point. Soil populations and levels of root colonization for the stages were assessed by estimating CFUs and root length. Results indicate that soil texture has a significant impact upon root morphology and root length. Root populations of M. phaseolina were significantly higher in sandy soil textures and lower in the fine-textured soils, suggesting an impact of soil water holding capacity in the root infection process. The effect of water stress on seedling root colonization by M. phaseolina indicates that early infection may be more important than previously thought. A field study was also conducted to determine the effect of the aforementioned variables in a 2-year field experiment conducted at two Kansas locations. Pathogen colonization was iii assessed by measuring colony-forming units (CFUs) from ground root tissue at R2-R4 (post-flowering/early pod development) and R8 (maturity) stages. Soil populations (pre-planting and post-harvest) of M. phaseolina, yield parameters, and plant characteristics were obtained. Results indicated that there are complex relationships between soil physiochemical properties (pH, NPK content, exchangeable cations, and organic matter) and soil texture (sand, soil, and clay composition), which may mitigate disease severity and pathogen levels in host tissue. Results also indicated that in natural M. phaseolina-infested soils, cropping history and soil texture play an important role in charcoal rot processes and influence the levels of pathogen soil populations, root colonization at maturity and, more importantly, soybean yield.
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Ramesh, Sunita. « Molecular mechanism of zinc uptake and regulation in cereals ». Title page, table of contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09PH/09phr1724.pdf.
Texte intégralRésumé :
Bibliography: leaves 174-204. "This work provides a starting point for understanding the molecular mechanisms of zinc uptake and the regulation of zinc transport in cereals. Zinc efficient cereals would yield more on soild with low zinc and could potentially result in increased zinc content grain."
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Molteno, Steve. « The characterization of Rooibos tea soils and their effects on nitrogen nutrition of the plant ». Bachelor's thesis, University of Cape Town, 1995. http://hdl.handle.net/11427/26686.
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Uribe, Botero Eduardo. « Response of corn to manganese application on Atlantic coastal plain soils ». Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/45679.
Texte intégralRésumé :
Although corn plants are tolerant of low levels of
available soil Mn, Mn deficiencies in corn were suspected on soils where Mn applications had previously increased
soybean seed yields. Five experiments were conducted
in farmer's fields to evaluate the response of
corn to Mn applications. Three band Mn and two broadcast
Mn studies were conducted in five field experiments
on Atlantic Coastal Plain soils. The mean increase in
corn grain yield in the band studies on three soils was
l
960 kg ha-1. Corn grain yields were not increased in
the broadcast Mn studies on Slagle and Dragston fine
sandy loams. Manganese uptake from the Slagle soil was
so high that Mn deficiency did not occur; whereas, Mn
uptake from the Dragston soil was so low that the deficiency
was not completely corrected by up to 24 kg Mn
hha-1 as broadcast MnSO4.Master of Science
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Kitchen, Julie Louise. « Nutrition and nutrional value of wheat grown in organic and conventional farming systems in South Australia ». Title page, table of contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phk618.pdf.
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Kroehler, Carolyn J. « The role of acid phosphatases in the phosphorus nutrition of arctic tundra plants ». Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/80295.
Texte intégralRésumé :
The acid phosphomonoesterase activity associated with two major rooting strategies in arctic tundra plants was examined: that of Eriophorum vagina tum, a dominant plant in tussock tundra ecosystems, with its predominantly non-mycorrhizal root system; and that of ectomycorrhizal roots.
Eriophorum has phosphatase activity which is evenly distributed along its root surface, has a pH optimum at soil pH (3.5-4.0), and continues at substantial rates at 1 °C. Inorganic phosphorus inhibits activity only 7 to 19%. In addition, Eriophorum has phosphatase activity associated with all the "below-ground" components of its tussock growth form: dead roots, leaf sheaths, and soil. Plants with higher tissue phosphorus growing in soils with higher available phosphate in general had higher live and dead root, leaf sheath, and soil phosphatase activity in both natural and manipulated sites of higher plant productivity. Yearly and seasonal variation sometimes exceeded differences among treatments, suggesting that enzyme activity would not provide a reliable measure of plant or soil phosphorus levels. Experiments with radiolabeled inositol hexaphosphate showed that Eriophorum is able to hydrolyze and absorb inorganic phosphate from an organic phosphate source. A comparison of enzyme hydrolysis rates with inorganic phosphate assimilation rates indicates that organic phosphate hydrolysis may occur as rapidly as inorganic phosphate absorption. Inorganic phosphate released by root surface phosphatase activity could satisfy approximately 65% of the annual phosphate demand of Eriophorum.
Phosphatases of two ectomycorrhizal fungi (Cenococcum geophilum and Entoloma sericeum) responded similarly to growth in axenic culture at 2 or 50 micromolar KH₂PO₄ or sodium inositol hexaphosphate: surface Vmax estimates were significantly greater for 2 micromolar- than for 50 micromolar-grown isolates. The presence of constitutive extracellular soluble phosphatase activity resulted in the appearance of inorganic phosphate in media initially supplied only with organic phosphate. The surface acid phosphatase activity of field-collected ectomycorrhizal roots of arctic Salix and Betula, however, did not respond in a consistent way to differences in soil characteristics. Activity differed more among "color types" or fungal types than among sites of different soil characteristics.Ph. D.
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Nuñez, Moreno Jesus Humberto. « Nutritional Studies on Pecans [Carya illinoinensis L. (Wangenh.) C. Koch] Growing in Irrigated Alkaline Soils ». Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/194206.
Texte intégralRésumé :
Annual application of N at rates of 118 (118N), 236 (236N), and 354 (354N) kg•ha⁻¹ on 35 year old 'Western Schley' pecan trees during four years had little effect on mineral composition and foliar N. No differences in yield, nut quality, and reproductive characteristics were found. Alternate bearing intensity in four consecutive years was 37, 33 and 28% in 118N, 236N, and 354N, respectively, with a significant linear response. Rates from 118 to 236 kg N•ha⁻¹ satisfy N needs for pecan in irrigated pecan orchard of the southwest of United States. The effect of one-time banding of zinc sulfate (74 kg Zn•ha⁻¹) and zinc-EDTA (19 kg Zn•ha⁻¹) was evaluated over a period of four years on ‘Wichita’ pecans growing in alkaline soil. Significant differences in foliar Zn levels were found one month after application of Zinc-EDTA. Differences also were noted during the next three years on approximately 25% of the sampling dates. Yield, leaflet area, and trunk cross sectional area were not affected. Zinc-EDTA increased Zn uptake by 'Wichita' pecan trees in alkaline conditions during three years. A field study indicated that manure or manure plus Zn increased foliar Zn levels in pecans after two years of annual applications. Manure (24 ton ha⁻¹) plus zinc sulfate (258 kg Zn•ha⁻¹ as zinc sulfate) treatment had the highest foliar Zn levels. No differences were observed in trunk growth, leaf area, leaf weight, nut filling, and yield. Manganese toxicity symptoms are exhibited when leaf Mn levels are higher than 1700 μg•g⁻¹ during the standard date sampling of July and affected reproductive characteristics and leaf and shoot growth. More severe visible symptoms include delayed budbreak and die-back of young shoots. In potted pecan trees, zinc EDTA treated trees had a foliar Zn of 244 μg•g⁻¹, in foliar sprayed trees (eight foliar sprays of a combination of zinc sulfate and UAN32) had 140 μg•g⁻¹, and in control trees had 33 μg•g⁻¹. Soil adsorption isotherms showed that of the three fertilizers evaluated Zn sulfate was adsorbed most strongly by the soil (1.5 mg Zn•g⁻¹ of soil). Soil adsorption from Zn EDTA solutions was insignificant.
Livres sur le sujet "Soils and nutrition"
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M, Attiwill P., et Adams Mark A, dir. Nutrition of eucalypts. Collingwood, Vic : CSIRO, 1996.
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Abadía, J., dir. Iron Nutrition in Soils and Plants. Dordrecht : Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0503-3.
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Miransari, Mohammad. Soil nutrients. Hauppauge, N.Y : Nova Science Publishers, 2011.
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Mahler, Robert Louis. Current nutrient status of soils in Idaho, Oregon and Washington. [Corvallis, Or.] : University of Idaho Cooperative Extension Service, Washington State University Cooperative Extension Service, Oregon State University Cooperative Extension Service, and U.S. Dept. of Agriculture, 1985.
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Depleted & contaminated soil and your food supply. New York : Rosen Pub., 2013.
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Soil, Grass and Cancer : Health of Animals and Men is Linked to the Mineral Balance of the Soil. Austin, Texas : Acres U.S.A., 1999.
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CEC/IUFRO Symposium on Nutrient Uptake and Cycling in Forest Ecosystem. CEC/IUFRO Symposium on Nutrient Uptake and Cycling in Forest Ecosystem : Halmstad, Sweden, 7-10 June 1993. ([Luxembourg] : [Office for Official Publications of the European Communities], 1993.
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Zhongguo nong tian sheng tai xi tong yang fen xun huan yu ping heng ji qi guan li. Beijing : Ke xue chu ban she, 2008.
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Whalen, Joann K. Soil fertility improvement and integrated nutrient management : A global perspective. Rijeka, Croatia : InTech, 2012.
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Jez, Joseph. Sulfur : A missing link between soils, crops, and nutrition. Madison, WI : American Society of Agronomy, 2008.
Trouver le texte intégralChapitres de livres sur le sujet "Soils and nutrition"
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Evert, Ray F., et Susan E. Eichhorn. « Plant Nutrition and Soils ». Dans Raven Biology of Plants, 683–707. New York : Macmillan Learning, 2013. http://dx.doi.org/10.1007/978-1-319-15626-8_30.
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Aizpurua, A., S. Alava, A. Castellón, A. Alonso et G. Besga. « Soil potassium determination in pasture soils in the basque country ». Dans Plant Nutrition, 744–45. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/0-306-47624-x_361.
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Elkina, G. Y. « Nutrient uptake and crop productivity on Podzolic soils (Alfisols) ». Dans Plant Nutrition, 870–71. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/0-306-47624-x_424.
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Holloway, R. E., I. Bertrand, A. J. Frischke, D. M. Brace, M. J. McLaughlin, W. Shepperd et R. D. Graham. « Fluid fertilisers — An efficient source of P for calcareous soils ». Dans Plant Nutrition, 832. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/0-306-47624-x_405.
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Nagaoka, T., J. Tanaka, K. Kouno et T. Ando. « Degradation of chlorinated aromatic acids from sludge compost in soils ». Dans Plant Nutrition, 848–49. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/0-306-47624-x_413.
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Hütsch, B. W., S. Zhang, K. Feng, F. Yan et S. Schubert. « Effect of pH on denitrification losses from different arable soils ». Dans Plant Nutrition, 962–63. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/0-306-47624-x_469.
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Brunner, I., S. Zimmermann et M. Genenger. « Fine roots of trees : Indicators for the element availability in forest soils and for forest soil conditions ». Dans Plant Nutrition, 920–21. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/0-306-47624-x_448.
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Sadeghzadeh, Behzad, et Zed Rengel. « Zinc in Soils and Crop Nutrition ». Dans The Molecular and Physiological Basis of Nutrient Use Efficiency in Crops, 335–75. Oxford, UK : Wiley-Blackwell, 2011. http://dx.doi.org/10.1002/9780470960707.ch16.
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Nietfeld, H. « Model calculations of the rhizosphere aluminium chemistry in acid forest soils ». Dans Plant Nutrition, 598–99. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/0-306-47624-x_290.
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Bertrand, I., R. E. Holloway et M. J. McLaughlin. « Fluid fertilisers — A better solution for growing wheat in alkaline soils ? » Dans Plant Nutrition, 700–701. Dordrecht : Springer Netherlands, 2001. http://dx.doi.org/10.1007/0-306-47624-x_339.
Texte intégralActes de conférences sur le sujet "Soils and nutrition"
1
Rusakov, Aleksey, Yulia Simonova, Aleksandr Ryumin, A. Popov et Natalya Lemeshko. « ESTIMATION OF THE FERTILITY OF AGRICULTURAL SOILS IN THE NORTHERN PART OF THE YAROSLAVSK REGION AND TRENDS OF THEIR EVOLUTIONARY CHANGES FOR A 30-YEAR POST AGROGENIC PERIOD BASED ON THE SOIL- ECOLOGICAL INDEX ». Dans Land Degradation and Desertification : Problems of Sustainable Land Management and Adaptation. LLC MAKS Press, 2020. http://dx.doi.org/10.29003/m1681.978-5-317-06490-7/81-86.
Texte intégralRésumé :
The assessment of the agricultural production potential of the soils of the former arable lands was carried out on the basis of the updated soil-ecological index. It was revealed that among the agrosoils of Poshekhonsk district, soils with 20-39 points prevail, which generally indicates low and medium levels of potential soil fertility in the studied area in the late perestroika period. Comparison of morphological and genetic properties of soils for the period 1988-1990 and for 2019 showed the trends of their evolutionary changes. Multidirectional trends in the transformation of soil properties, developed on a contrasting lithogenic parent rocks, with a change in land use during the last 30-35-year period have been established. In loamy soils, stable hydromorphism features are observed everywhere, degradation processes prevail, expressed in dehumification, a sharp depletion of mobile forms of mineral nutrition elements of plants and, in some cases, acidification of humus postagrogenic horizons. It has been established that fallow soils on loamy parent material are characterized by a noticeable (by 1.1-1.9 times) decrease in the values of soil-ecological index in comparison with their arable state. On the contrary, in soils of light particle size distribution, the dominant processes are due to an increase in humus content and a decrease in acidity. The specificity of postagrogenic evolution and the emergence of new soil properties should be taken into account when performing soil-agroecological assessments and forecasting agricultural production potential against the background of changed climatic conditions.
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Kuleshova, L. A., A. S. Kasakova et I. S. Tatyanchenko. « INFLUENCE OF PRECURSORS ON THE CONTENT OF MINERAL PHOSPHORUS FRACTIONS IN THE SOILS OF RICE FIELDS IN THE ROSTOV REGION. » Dans STATE AND DEVELOPMENT PROSPECTS OF AGRIBUSINESS Volume 2. DSTU-Print, 2020. http://dx.doi.org/10.23947/interagro.2020.2.704-708.
Texte intégralRésumé :
The article is devoted to the problem of phosphoric nutrition of rice on chestnut soils of the northernmost zone of rice cultivation in Russia. The paper reveals the role of water-soluble fractions of phosphorus, aluminosilicates, iron phosphates and calcium phosphates in the nutrition of rice plants during the growing season. The influence of the previous culture on the content and consumption of these fractions was established.
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Novak, S. O., E. V. Boyarkin et V. A. Agafonov. « The yield of grain crops depending on the mineral nutrition and various preparations for foliar top dressing ». Dans Растениеводство и луговодство. Тимирязевская сельскохозяйственная академия, 2020. http://dx.doi.org/10.26897/978-5-9675-1762-4-2020-133.
Texte intégralRésumé :
The article presents research data on the effect of various preparations for foliar dressing and the background of mineral nutrition on the yield of spring grain crops on gray forest soils of Predbaikalia.
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Tomic, Dalibor, Vladeta Stevovic, Dragan Djurovic, Milomirka Madic, Milos Marijanovic, Aleksandar Simic et Jasmina Knezevic. « ZNAČAJ PRAVILNE ISHRANE KRMNIH LEGUMINOZA FOSFOROM NA KISELIM ZEMLJIŠTIMA ». Dans XXVI savetovanje o biotehnologiji sa međunarodnim učešćem. Agronomski fakultet Univerziteta u Kragujevcu, 2021. http://dx.doi.org/10.46793/sbt26.037t.
Texte intégralRésumé :
In the Republic of Serbia, acid soils cover about 60% of the total arable land. On such soils, numerious micro and macro elements are hardly accessible for plants. Sufficient supply of leguminous plants with phosphorus is very important for the processes of their growth and development, nodulation and nitrogen fixation. The aim of this study was to analyze the importance of proper nutrition of leguminous plants with phosphorus on acid soils and to point out the problems that exist in such conditions, as well as the possible ways to solve them.
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Яшин, Валерий Михайлович. « THE ROLE OF IRRIGATION SUPPLY OF GROUND WATER IN CHANGING THE ENVIRONMENTAL CONDITIONS OF IRRIGATED AREAS ». Dans Национальная безопасность России : актуальные аспекты : сборник избранных статей Всероссийской научно-практической конференции (Санкт-Петербург, Сентябрь 2020). Crossref, 2020. http://dx.doi.org/10.37539/nb187.2020.71.82.006.
Texte intégralRésumé :
В статье рассматривается взгляд автора и материалы исследований формирования ирригационного питания грунтовых на орошаемых землях и анализ его влияния на изменение экологических условий. Если влияние орошения мелиорируемых почв осуществляется на площади непосредственной реализации мелиоративных мероприятий, то его влияние за счет увеличения инфильтрационного питания грунтовых вод перераспределяется на значительные территории на иерархических уровнях от локального до бассейнового. The article discusses the author's view and research materials on the formation of irrigation nutrition of ground on irrigated lands and the analysis of its impact on changes in environmental conditions. If the influence of irrigation of reclaimed soils is carried out on the area of direct implementation of reclamation measures, then its influence by increasing the infiltration supply of groundwater is redistributed to significant territories at hierarchical levels from local to basin.
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Karlsons, Andis, Anita Osvalde et Laura Abolina. « NITROGEN AND PHOSPHORUS EFFECT ON AMERICAN CRANBERRY GROWTH, YIELD AND MINERAL ELEMENT COMPOSITION ». Dans 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/3.1/s13.33.
Texte intégralRésumé :
The industrial cultivation of American cranberry (Vaccinium macrocarpon Aiton) in Latvia was started during last 20 years with total plantings of more than 125 ha today. As a native wetland plant, commonly cranberries grows on poor, acid soils and are characterized as nutrients low requiring crop, however, balanced plant nutrition is vitally important to realize the full potential of cranberries as crop, to ensure adequate growth and yield production. Previous results obtained by authors from different cranberry producing plantings in Latvia frequently showed inadequate cranberry tissue supply with N and P. A field trial were established to examine the impact of N and P fertilizer rates on cranberry yield, fruit quality, morphological factors, and mineral element supply. Field experiments on cranberry cultivar �Bergman� were conducted during 2019 cropping season in a commercial plantation established on an excavated peat bog in Latvia. The cranberries received five levels of N (0 to 40 kg N ha-1) and P (0 to 30 kg P ha-1) as well as N and P treatment combinations applied in spring. Cranberry leaf analyses and soil (peat) testing were used as a diagnostics tool to reveal nutrient (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo, B), soil pH and EC status. In general, crop characters were significantly influenced by different levels of N and P. As expected, the results showed that combined N and P treatments with the highest rates: N30/P20 and N40/P30 resulted in the highest yields and yield parameters, as well as ensured optimal N and P concentrations in cranberry tissues. It should be noted that the rates of applied fertilizers were environmentally safe as the nutrient concentrations recommended for peat growing medium were not exceeded.
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« Capturing Bio-Sensing Solutions : Biomonapp’s Story about the Seasons of Change across a Global Sustainable Landscape - Monitoring for Sustainable Bioremediation in Rural & ; Urban Farms, Soil, Agronomy, & ; Aquaculture ». Dans InSITE 2018 : Informing Science + IT Education Conferences : La Verne California. Informing Science Institute, 2018. http://dx.doi.org/10.28945/4052.
Texte intégralRésumé :
Aim/Purpose: This paper addressed the topics of sustainable agronomy, aquaculture, hydroponics and soil monitoring methods that show how to move towards a repairing mode and bioremediation in many locations across the globe. Background: Sixty percent of the world’s major terrestrial ecosystems are being degraded; the human ecological footprint is spreading across the globe. The major human impact on terrestrial ecosystems in the form of depletion of ground water, over grazing of livestock, clearing for agriculture, timber and urban development, soil damage from off road vehicles, hydroelectric dams and reservoirs, and air pollution from urban areas and power plants. The cost to bio remediate is in the trillions. Methodology: AG biotech methodologies and applications Contribution: The paper bridges such gaps and informs about brave entrepreneurs and university and community individuals with innovative ideas and emerging technologies that gain the momentum for funding and monitoring nutrient uptake and toxic removal of harmful chemicals from water, soil, plants and fish for restoration to take place. Such techniques begin to conquer the giant by restoring the wealth to our soils and water, rural and urban farmlands and forests that retain and capture natural capital and ensure that nutrition and value added resources minerals are not lost. Findings: Biomonapp can detect and make recommendations for repairing & making sustainable solutions, many entrepreneurs & academics have pioneered ways to find SUS solutions Recommendations for Practitioners: Read from the articles and books listed in the references of this paper to understand the need for bioremediation. Use Biomonapp to diagnose water, soil & fish problems & find solutions. Attend conferences & seminars about SUS responsibility & phytoremediation Recommendation for Researchers: To investigate the phytoremediation and bioremediation techniques. Applications for Biomonapp for plants, water, soil, & animals to rejuvenate and repair water, soil and urban & rural communities Impact on Society: These ideas give the power back to local people who can learn to enhance their lives not only by foods but the sustainable green jobs that are being created to make sure urban and rural areas truly are sustainable. Future Research: The results of monitoring with biosensors & bio monitoring methods with regards to sustainable bioremediation, renovating, continued SUS responsibility training, continued evidence of repair and protecting natural capital & ecosystem services
8
Samfira, Ionel, Costel Barliba, Marinel Horablaga, Gheorghe David et Livia Barliba. « EVALUATION OF THE INFLUENCE OF ABIOTIC FACTORS ON THE PRODUCTIVE CHARACTERISTICS IN THE SOILS OF THE GRASSLANDS ECOSYSTEM ». Dans 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/3.1/s13.30.
Texte intégralRésumé :
The soils potential is the result of interdependence between the characteristics of the vegetation and the natural environment, also the level of production is the result of the influence of determining factors: natural environmental factors and technological factors. The influence of biotope relief factors on the above-ground vegetation is a direct consequence of the altitudinal differentiation of climatic conditions, a vegetation layer and implicitly a rather varied and complex area soil cover. It is unanimously appreciated that in order to have a rich and quality harvest must be ensured the quantities of fertilizers and the necessary amendments to improve the nutritional conditions of the crop species or grassland areas. In this study we use a qualitative-productive evaluation (QPE) of grasslands soils represents according to the degree of favorability (suitability) using as a comparison tool technical indices or rating notes. Based on this study a soil map and legend were developed depending on the specific properties for each soil and land unit following each group of soils limitations. The results showed in the studied area the reaction of the soil (pH) is generally weakly acidic, the weighted average pH value being 6.68, with phosphorus supply generally medium, the weighted average phosphorus content being 22.67 ppm. The supply of potassium to the soils is very good, the weighted average potassium content being 208 ppm K. Compared to those results, depending on the specific properties for each soil and land unit was identified the soils limitations and a specific fertilization to comply with the European Code of Good Agricultural Practice so as to ensure good future production potential.
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Zhuk, Ekaterina. « Effect of nitrogen fertilizer Life Force Humic N on the yield and quality of the green mass of corn in the conditions of the Republic of Belarus ». Dans Multifunctional adaptive fodder production. ru : Federal Williams Research Center of Forage Production and Agroecology, 2022. http://dx.doi.org/10.33814/mak-2022-28-76-134-138.
Texte intégralRésumé :
Corn plays a leading role in providing the livestock industry with green and juicy feeds. To increase the yield and quality of green mass, the use of nitrogen fertilizers is of great importance [1]. In a field experiment on sod-podzolic soils in the conditions of the Minsk region, on the basis of LLC "Gastellovskoye" of the Minsk district, the influence of nitrogen fertilizer Life Force Humic N on the yield and quality of the green mass of the Dolphin corn hybrid was studied. Water-soluble nitrogen fertilizer Life Force Humic N on corn crops was used in phases: 4–6 leaves, sweeping of the panicle and the beginning of flowering of the crop. The content of the main elements of nutrition (nitrogen, phosphorus, potassium) in the green mass of corn under the influence of the fertilizer Life Force Humic N varied within the error of the experiment and at the level with the use of control. No significant changes in the protein content depending on the use of equivalent doses of mineral nitrogen (control) and Life Force Humic N fertilizer have been established. The maximum protein content (5.6–5.7%) was noted both in the variant with the use of top dressing with standard nitrogen fertilizer and with the Life Force Humic N. fertilizer. When cultivating corn for green mass, the use of three-fold non-root treatment of crops with liquid water-soluble nitrogen fertilizer Life Force Humic N increased the yield of the green mass of the crop by 31 c / ha. When cultivating corn for green mass, the use of non-root treatments with Life Force Humic N fertilizer at a dose of 1 l/ ha is recommended.
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Kovshova, Valentina, et Anna Smirnova. « Changes in forage quality of a long-term pasture depending on mineral fertilizer and weather conditions ». Dans Multifunctional adaptive feed production 27 (75). ru : Federal Williams Research Center of Forage Production and Agroecology, 2022. http://dx.doi.org/10.33814/mak-2022-27-75-125-133.
Texte intégralRésumé :
The results of research on changes in productivity and nutritional value of long-term pasture grass on drained peat soil depending on the methods of mineral fertilizer and agro-climatic conditions of the Volga-Vyatka economic region are presented. The role of the anthropogenic factor in changing the botanical composition of pasture grass, its productivity and the quality of the resulting feed is assessed. The parameters of the control of the collection of digestible protein from 1 ha of pasture grass under different types of weather have been determined. Experimental data confirm that the use of drained peat soils in grassland farming is the most promising way to solve the problem of forage production and preservation of the organic layer of peat soil.
Rapports d'organisations sur le sujet "Soils and nutrition"
1
Shenker, Moshe, Paul R. Bloom, Abraham Shaviv, Adina Paytan, Barbara J. Cade-Menun, Yona Chen et Jorge Tarchitzky. Fate of Phosphorus Originated from Treated Wastewater and Biosolids in Soils : Speciation, Transport, and Accumulation. United States Department of Agriculture, juin 2011. http://dx.doi.org/10.32747/2011.7697103.bard.
Texte intégralRésumé :
Beneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levelsBeneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levels that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction.
2
Setboonsarng, Sununtar, et Elsbeth Gregorio. Large-Scale Soil Health Restoration : The Way Forward for Reversing Climate Change while Enhancing Food and Nutrition Security. Asian Development Bank, novembre 2017. http://dx.doi.org/10.22617/wps179128-2.
Texte intégral
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Chen, Yona, Jeffrey Buyer et Yitzhak Hadar. Microbial Activity in the Rhizosphere in Relation to the Iron Nutrition of Plants. United States Department of Agriculture, octobre 1993. http://dx.doi.org/10.32747/1993.7613020.bard.
Texte intégralRésumé :
Iron is the fourth most abundant element in the soil, but since it forms insoluble hydroxides at neutral and basic pH, it often falls short of meeting the basic requirements of plants and microorganisms. Most aerobic and facultative aerobic microorganisms possess a high-affinity Fe transport system in which siderophores are excreted and the consequent Fe complex is taken up via a cognate specific receptor and a transport pathway. The role of the siderophore in Fe uptake by plants and microorganisms was the focus of this study. In this research Rhizopus arrhizus was found to produce a novel siderophore named Rhizoferrin when grown under Fe deficiency. This compound was purified and its chemical structure was elucidated. Fe-Rhizoferrin was found to alleviate Fe deficiency when applied to several plants grown in nutrient solutions. It was concluded that Fe-Rhizoferrin is the most efficient Fe source for plants when compared with other among microbial siderophores known to date and its activity equals that of the most efficient synthetic commercial iron fertilizer-Fe EDDHA. Siderophores produced by several rhizosphere organisms including Rhizopus Pseudomonas were purified. Monoclonal antibodies were produced and used to develop a method for detection of the siderophores produced by plant-growth-promoting microorganisms in barley rhizosphere. The presence of an Fe-ferrichrome uptake in fluorescent Pseudomonas spp. was demonstrated, and its structural requirements were mapped in P. putida with the help of biomimetic ferrichrome analogs. Using competition experiments, it was shown that FOB, Cop B and FC share at least one common determinant in their uptake pathway. Since FC analogs did not affect FOB or Cop-mediated 55Fe uptake, it could be concluded that these siderophores make use of a different receptor(s) than FC. Therefore, recognition of Cop, FOB and FC proceeds through different receptors having different structural requirements. On the other hand, the phytosiderophores mugineic acid (MA and DMA), were utilized indirectly via ligand exchange by P. putida. Receptors from different biological systems seem to differ in their structural requirements for siderophore recognition and uptake. The design of genus- or species-specific drugs, probes or chemicals, along with an understanding of plant-microbe and microbe-microbe relationships as well as developing methods to detect siderophores using monoclonal antibodies are useful for manipulating the composition of the rhizosphere microbial population for better plant growth, Fe-nutrition and protection from diseases.
4
Crowley, David E., Dror Minz et Yitzhak Hadar. Shaping Plant Beneficial Rhizosphere Communities. United States Department of Agriculture, juillet 2013. http://dx.doi.org/10.32747/2013.7594387.bard.
Texte intégralRésumé :
PGPR bacteria include taxonomically diverse bacterial species that function for improving plant mineral nutrition, stress tolerance, and disease suppression. A number of PGPR are being developed and commercialized as soil and seed inoculants, but to date, their interactions with resident bacterial populations are still poorly understood, and-almost nothing is known about the effects of soil management practices on their population size and activities. To this end, the original objectives of this research project were: 1) To examine microbial community interactions with plant-growth-promoting rhizobacteria (PGPR) and their plant hosts. 2) To explore the factors that affect PGPR population size and activity on plant root surfaces. In our original proposal, we initially prqposed the use oflow-resolution methods mainly involving the use of PCR-DGGE and PLFA profiles of community structure. However, early in the project we recognized that the methods for studying soil microbial communities were undergoing an exponential leap forward to much more high resolution methods using high-throughput sequencing. The application of these methods for studies on rhizosphere ecology thus became a central theme in these research project. Other related research by the US team focused on identifying PGPR bacterial strains and examining their effective population si~es that are required to enhance plant growth and on developing a simulation model that examines the process of root colonization. As summarized in the following report, we characterized the rhizosphere microbiome of four host plant species to determine the impact of the host (host signature effect) on resident versus active communities. Results of our studies showed a distinct plant host specific signature among wheat, maize, tomato and cucumber, based on the following three parameters: (I) each plant promoted the activity of a unique suite of soil bacterial populations; (2) significant variations were observed in the number and the degree of dominance of active populations; and (3)the level of contribution of active (rRNA-based) populations to the resident (DNA-based) community profiles. In the rhizoplane of all four plants a significant reduction of diversity was observed, relative to the bulk soil. Moreover, an increase in DNA-RNA correspondence indicated higher representation of active bacterial populations in the residing rhizoplane community. This research demonstrates that the host plant determines the bacterial community composition in its immediate vicinity, especially with respect to the active populations. Based on the studies from the US team, we suggest that the effective population size PGPR should be maintained at approximately 105 cells per gram of rhizosphere soil in the zone of elongation to obtain plant growth promotion effects, but emphasize that it is critical to also consider differences in the activity based on DNA-RNA correspondence. The results ofthis research provide fundamental new insight into the composition ofthe bacterial communities associated with plant roots, and the factors that affect their abundance and activity on root surfaces. Virtually all PGPR are multifunctional and may be expected to have diverse levels of activity with respect to production of plant growth hormones (regulation of root growth and architecture), suppression of stress ethylene (increased tolerance to drought and salinity), production of siderophores and antibiotics (disease suppression), and solubilization of phosphorus. The application of transcriptome methods pioneered in our research will ultimately lead to better understanding of how management practices such as use of compost and soil inoculants can be used to improve plant yields, stress tolerance, and disease resistance. As we look to the future, the use of metagenomic techniques combined with quantitative methods including microarrays, and quantitative peR methods that target specific genes should allow us to better classify, monitor, and manage the plant rhizosphere to improve crop yields in agricultural ecosystems. In addition, expression of several genes in rhizospheres of both cucumber and whet roots were identified, including mostly housekeeping genes. Denitrification, chemotaxis and motility genes were preferentially expressed in wheat while in cucumber roots bacterial genes involved in catalase, a large set of polysaccharide degradation and assimilatory sulfate reduction genes were preferentially expressed.
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Woldeyohanes, Tesfaye, Karl Hughes, Kai Mausch et Judith Oduol. Adoption of improved grains legumes and dryland cereals crop varieties : A synthesis of evidence. World Agroforestry, 2021. http://dx.doi.org/10.5716/wp21022.pdf.
Texte intégralRésumé :
Like other crop improvement programs, a key prerequisite for the CGIAR Research Program on Grain Legumes and Dryland Cereals (CRP GLDC) to generate large-scale impact is large-scale adoption. Hence, evidencing the breadth and depth of such adoption is both of intrinsic interest and important for estimating downstream impacts, such as improved food and nutritional security, income, resilience, and soil health. While various GLDC adoption studies have been undertaken, a recent effort to systematically review these studies and synthesize the results is lacking. We undertook such a review, identifying 69 studies and 35 independent country crop combinations (CCCs). To generate aggregated and updated estimates of GLDC improved varietal adoption, we devised and applied a procedure to estimate national cropping areas under such varieties and, in turn, the number of adopting households. Estimates derived from household surveys and expert opinion solicitation are treated with higher and lower levels of confidence, respectively. As of 2019, we estimate from higher confidence studies that improved GLDC crops were cultivated on 15.37 million hectares of land by 17.64 million households in CRP GLDC’s 13 priority countries. With the inclusion of lower confidence studies, these numbers increase to 32 and 44.64 million, respectively. We are further confident that the program exceeded its adoption target of 8.9 million newly adopting households from 2011, particularly when likely spillovers vis-à-vis non-surveyed areas, non-priority countries, and non-priority crops in priority countries are considered.
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Eshel, Amram, Jonathan P. Lynch et Kathleen M. Brown. Physiological Regulation of Root System Architecture : The Role of Ethylene and Phosphorus. United States Department of Agriculture, décembre 2001. http://dx.doi.org/10.32747/2001.7585195.bard.
Texte intégralRésumé :
Specific Objectives and Related Results: 1) Determine the effect of phosphorus availability on ethylene production by roots. Test the hypothesis that phosphorus availability regulates ethylene production Clear differences were found between the two plants that were studied. In beans ethylene production is affected by P nutrition, tissue type, and stage of development. There are genotypic differences in the rate of ethylene production by various root types and in the differential in ethylene production when P treatments are compared. The acceleration in ethylene production with P deficiency increases with time. These findings support the hypothesis that ethylene production may be enhanced by phosphorus deficiency, and that the degree of enhancement varies with genotype. In tomatoes the low-P level did not enhance significantly ethylene production by the roots. Wildtype cultivars and ethylene insensitive mutants behaved similarly in that respect. 2) Characterize the effects of phosphorus availability and ethylene on the architecture of whole root systems. Test the hypothesis that both ethylene and low phosphorus availability modify root architecture. In common bean, the basal roots give rise to a major fraction of the whole root system. Unlike other laterals these roots respond to gravitropic stimulation. Their growth angle determines the proportion of the root length in the shallow layers of the soil. A correlation between ethylene production and basal root angle was found in shallow rooted but not deep-rooted genotypes, indicating that acceleration of ethylene synthesis may account for the change in basal root angle in genotypes demonstrating a plastic response to P availability. Short-time gravitropic response of the tap roots of young bean seedlings was not affected by P level in the nutrient solution. Low phosphorus specifically increases root hair length and root hair density in Arabidopsis. We tested 7 different mutants in ethylene perception and response and in each case, the response to low P was lower than that of the wild-type. The extent of reduction in P response varied among the mutants, but every mutant retained some responsiveness to changes in P concentration. The increase in root hair density was due to the increase in the number of trichoblast cell files under low P and was not mediated by ethylene. Low P did not increase the number of root hairs forming from atrichoblasts. This is in contrast to ethylene treatment, which increased the number of root hairs partly by causing root hairs to form on atrichoblasts. 3) Assess the adaptive value of root architectural plasticity in response to phosphorus availability. A simulation study indicated that genetic variation for root architecture in common bean may be related to adaptation to diverse competitive environments. The fractal dimension of tomato root system was directly correlated with P level.