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Spedding, Timothy Andrew. "Soil microbial dynamics in response to tillage and residue management in a maize cropping system." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=79133.
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The impact of tillage and residue management on soil microorganisms was studied over the maize (Zea mays L.) growing season in southwestern Quebec. Tillage and residue treatments were imposed on a sandy loam to loamy sand soil in fall 1991. Treatments consisted of no till, reduced tillage, and conventional tillage with crop residues either removed from (-R) or retained on (+R) experimental plots, laid out in a randomized complete block design. Soil microbial biomass carbon (SMB-C), soil microbial nitrogen (SMB-N) and phospholipid fatty acid (PLFA) concentrations were measured four times, at two depths (0--10 cm, 10--20 cm), over the 2001 growing season. Sample periods were: May 7th (pre planting), June 25 th, July 16th, and September 29th (prior to corn harvest). The effect of time was of a greater magnitude than those attributed to tillage or residue treatments. While SMB-C showed no seasonal change (160 mug C g-1 soil); SMB-N was responsive to mineral nitrogen fertilizer; and PLFA data showed an increase in fungi and total PLFA throughout the season. PLFA profiles showed better distinction between sampling period, and depth, than treatments. Of the two treatments, the effect of residue was more pronounced than that of tillage, with increased SMB-C and SMB-N (6.1% and 96%) in +R plots compared to -R plots. This study illustrated that measuring soil quality based on soil microbial components must take into account seasonal changes in soil physical, chemical conditions, and nutrient supply.
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Heineman, Arne M. "Species selection for alley cropping in Western Kenya : system management, nutrient use efficiency and tree-crop compatibility (1988-1995)." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318545.
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Kadango, Tendayi Lovemore. "Farmers' perceptions of insect pests in the Eastern Cape maize-based cropping systems and the effects of crop residue management on insect pest populations." Thesis, University of Fort Hare, 2018. http://hdl.handle.net/10353/6202.
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Maize (Zea mays L.) is one of the most important crops in South Africa that is cultivated for food, feed and as a cash crop. Maize in the Eastern Cape is typically grown for consumption and the Province is one of the least producers owing to small landholdings, poor production conditions and pests. This study investigated: (i) the different maize cropping systems smallholder farmers practice in the Eastern Cape (EC), (ii) the major maize insect pests within the identified cropping systems, (iii) the perceptions of Eastern Cape smallholder maize farmers on the effects of insect pests, and (iv) the effects of crop residues on insect pests’ population dynamics. Four major cropping systems namely: maize sole cropping without rotations by government sponsored farmers (GCP) (94 percent), maize intercropping without rotations by independent farmers (IF) (79 percent), maize sole cropping without rotations by IF (67 percent) and maize intercropping without rotations by GCP (61 percent) were identified. The choice of a cropping system by the smallholder farmers was significantly influenced by source of sponsorship, the difference in their district localities, tenure system, availability of inputs and farming equipment, percentage of farmland farmers allocate to maize, maize varieties, farming experience, fallow operations and access to irrigation facilities. The major constraints faced by the farmers in maize production are the attack by insect pests, weeds competition, drought, the lack of fencing around the fields and destruction by mammals. The major insect pests identified were stalk borers (Busseola fusca, Chilo partellus), cutworms (Agrotis spp.), aphids (Rhopalosiphum maidis), bollworms (Helicoverpa armigera) and weevils (Sitophylus spp.). The most popular control measures employed were the use of GM maize and pesticides. Results from the field trial showed that field crickets were the major ground dwelling insect pests observed followed by bollworms and cutworms. However, there were no significant influence of residue retention on the insects’ diversity indices, richness, and evenness. Above ground insects sampling revealed the domination by four major insects namely, cutworms, maize stalk borer, bollworms, and spotted stalk borer. Residue management significantly influenced the infestation by spotted stalk borer only on maize plots. However, the general trend was that there was less infestation by the insects in plots where residues were retained than the ones with residue removed. Results from the study indicate that government sponsorship is significantly influencing the maize cropping systems of the smallholder farmers of the Eastern Cape.
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Fischler, Martin. "Legume green manures in the management of maize-bean cropping systems in eastern Africa with special reference to crotalaria (C. ochroleuca G. Don.) /." Zürich, 1997. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=12099.
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Chabi-Olaye, Adenirin. "Roles of inland valleys and maize cropping systems in the management of stem borers and their natural enemies in the humid forest of Cameroon." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=976147122.
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Ganyani, Lloyd Munashe. "Evaluating summer cover crop species and management strategies for rainfed maize based cropping systems in the central region of the Eastern Cape Province of South Africa." Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/373.
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The overall objective of the whole study was to assess whether conservation agriculture (CA) systems can work in the Eastern Cape Province (EC). The CA systems were engaged through cover cropping to address land degradation problems by emphasizing high biomass production in order to realize short term benefits such as moisture conservation, weed suppression and soil fertility benefits under rainfed conditions in the central region of the Eastern Cape province. Since rainfall is the most limiting factor to crop production in the EC, a within season rainfall distribution analysis was conducted to expose the quality of the season (onset, end and duration) and hence the feasibility of CA systems to guide agronomic decisions by farmers in EC. To assess season parameters, thirty four years of daily rainfall was collected from the University of Fort Hare Research station and used to conduct the rainy pentad (5 day rainfall totals) analysis and the daily rainfall analysis using INSTAT software programme. Based on the pentad analysis, results showed that Alice does not have a rainy season in 1 out of 2 years (50% probability) but has one in 1 out of 4 years (25% probability level). This criterion proved to be harsher and conservative when compared to the daily rainfall approach which is more precise in measuring trends on season parameters. The daily rainfall analysis indicated a 65% feasibility for the dry land cropping systems in the EC. The pentad analysis however was effective in illustrating seasonality and it showed that the wet season begins on the 1st of November, ending on the 22nd of March lasting for 140 days. Though the season duration appeared too long, the existence of dry spells during critical growth stages adversely affects the quality of the season. The daily rainfall analysis also managed to derive a signal which can guide planting decisions. For planting to be successful, this analysis determined that 20 mm of rain should be received in two consecutive days after the 1st of November. A screening trial for cover crop biomass production and weed suppression was conducted on-station Fort Hare Research Farm (32°46' S and 26° 50' E), and Msobombvu village (MSBV) (32°44' S, and 26° 55' E) over two seasons (2007/08 and 2008/09). Six summer cover crops i.e. cowpea (Vigna unguiculata), dolichos lablab (Dolichos argenteus), sunnhemp (Crotalaria juncea), buckwheat (Fagopyrum sagittatum), forage sorghum (Sorghum bicolor) and sunflower (Helianthus annus) were evaluated for biomass yield, and weed suppression. Decomposition rates, moisture conservation and residual effects of these cover crops on the succeeding main crop were also evaluated under dryland conditions. The screening trial was laid in randomized complete block design replicated three times. Forage sorghum (Sorghum bicolor) and sunflower (Helianthus annus) were identified as high biomass producers and their dry matter yields ranged from 8 -12 t ha-1. These cover crops can be useful in generating high biomass in rainfed cropping systems in the EC. Other cover crops produced 3 - 4 t ha-1 of biomass which fell short of the 6 t ha-1 expected benchmark. However, these biomass yields were important in weed management since all cover crop species showed a similar degree of weed suppression which surpassed the weed fallow treatment. As dead mulches, the cover crops failed to show residual moisture conservation and weed control benefits for the succeeding maize crop mainly because of poor residue persistence, and low harvestable fallow rainfall. Buckwheat (Fagopyrum esculentum), was selected for further investigations in a follow up trial on station in 2008/09 season because of its weed smothering qualities, suitability to short cycle rotations, and possible allelopathic properties. The trial aimed at finding weed and cost effective management options of buckwheat that are none detrimental to the succeeding maize crop. Results showed that cropping systems where buckwheat is followed by a main crop may not work as they are unprofitable with respect to R100 rand invested. Though perceived to have allelopathic properties, buckwheat failed to demonstrate the possibilities of allelopathic action against weeds. Intercropping trial was conducted on-station in 2007/8-2008/09 seasons to try and find better ways of fitting legume cover crops into maize based cropping systems without compromising production of staple cereals on limited landholdings. The trials evaluated three factors in factorial combination, cover crop planting date, intercropping strategy, and cover crop species. The trial was laid as 2 x 2 x 3 factorial arranged in a split-split plot design. The main plot factor was cover crop planting date, cover crops simultaneously planted with maize and cover crop planted two weeks after planting maize (DKC 61-25). The sub-plot factor was intercropping strategy, strip intercropping and betweenrow intercropping. The sub-sub-plot factor was cover crop species, Dolichos lablab (Dolichos argenteus (Highworth), and Cowpea Vigna ungiculata (Agrinawa) plus control plots of sole maize. Results showed that same time planting of leguminous cover crops with maize using the in-between row intercropping patterns can derive appreciable system biomass (maize/cover crop) yields, utilize land efficiently whilst getting favourable maize grain yield. Based on the rainfall analysis, results showed that the probability of success when relay seeding cover crops after two weeks into standing maize is low (15% chances of success). This suggests that relay intercropping strategies would not work due to the unavailability of a good quality season.
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Chim, Bee Khim. "Alternative and Improved Cropping Systems for Virginia." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/79721.
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Feed grain consumption in Virginia and the mid-Atlantic region is more than double the total production. Producing more feed grains in this region could generate more profit for grain growers and lower costs for end-users. Increased feed grain production in this region will necessitate improved corn (Zea mays L.) management techniques and adoption of alternative feed grains such as grain sorghum (Sorghum bicolor L.). In order to achieve our overall objective of increased corn and grain sorghum production in the region, experiments were conducted to assess tools with the ability to increase the efficiency of sidedress nitrogen (N) application for corn and to test the performance of grain sorghum in both full season and double-crop rotations in this region.
For the corn studies, seven field experiments were established in 2012-2014 with four replications in a randomized complete block design. Treatments included a complete factorial of four different preplant N rate (0, 45, 90, 134 kg ha-1) with three different approach simulation model-prescribed rates (Virginia Corn Algorithm, Maize-N, Nutrient Expert-Maize) and the standard Virginia yield-goal based approach. No differences in corn yield were found between the different simulation model and preplant N rate, however the prescribed sidedress N rate varied significantly due to the simulation model, preplant N rate and the interaction between them. The nitrogen use efficiency (NUE) was estimated based on partial factor productivity (PFP) of nitrogen. The greatest PFP resulted from use of the Virginia Corn Algorithm (VCA), which produced 68 kg grain kg N-1 compared with 49 kg grain kg N-1 for the yield-goal based approach. While the VCA shows promise as a tool for improving NUE of sidedress applications in corn, more research is needed to validate performance.
Soybean (Glycine max L.) is often double-cropped after small grain in the mid-Atlantic region. Growing grain sorghum in this niche in the cropping system instead could result in greater overall feed grain production. In order to assess the performance of grain sorghum as an alternative in common cropping systems, four field experiments were established at the Southern Piedmont Agriculture Research and Extension Center (SPAREC) and Tidewater Agriculture Research and Extension Center (TAREC), near Blackstone and Holland, Virginia, respectively. The experiments were conducted using a split plot design with four replications and fourteen treatments. Main plot was winter small grain crop; either barley (Hordeum vulgare L.), triticale (x Triticosecale.), wheat (Triticum aetivum L.) or winter-fallow and the subplot either soybean or sorghum. In three of four instances, full season sorghum yields were greater than double-cropped sorghum after small grain. At two locations, sorghum yields following triticale were lower than when following barley, possibly indicating an antagonistic or allelopathic effect of triticale. The most profitable cropping system was wheat-soybean based on the price assumptions and measure yields in this experiment. Among the sorghum cropping system, the most profitable system was also wheat-sorghum. Sorghum can be successfully grown in both full-season and double-crop systems and offers good potential to increase feed grain production in this region.Ph. D.
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Omokanye, Akim Tunde, University of Western Sydney, of Science Technology and Environment College, and Centre for Horticulture and Plant Sciences. "Biological and economic evaluation of maize-based cropping systems for Nigerian smallholders." THESIS_CSTE_HPS_Omokanye_A.xml, 2004. http://handle.uws.edu.au:8081/1959.7/797.
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Indigenous African shifting cultivation production systems, that were developed over many generations and took into account production potential as well as the constraints imposed by natural resources, are no longer practicable for Nigerian smallholder farmers. These systems relied on long fallow for fertility restoration after a period of cropping. Overpopulation has resulted in lower per capita land availability, necessitating a shift to sedentary cultivation systems. In such systems, fallow is short term (months) compared to shifting systems, where it lasted several years. This shift has resulted in overexploitation of land resources and despite intensification of agricultural production methods, non-sustainable demand on the natural resource base has increased and crop and animal production has declined. This study examined the performance of five maize-based cropping systems consisting of cereal-legume, cereal-cereal and cereal bare fallow rotations, to identify systems that have potential for increased agricultural production in the subhumid and mid-altitude zones of Nigeria. The study was conducted at Richmond, near Sydney, in NSW, Australia from 2000 to 2003. The trial investigated the effects of the combined use of legumes and N fertilizer in CSs to maintain or improve soil fertility, maize crop and maize storage silage production and yield and quality of all crop residues. This study showed that inclusion of a legume in the rotation is an important production and income generating strategy. Owing to their potential for increased maize productivity, to build up N-rich systems and to improve small holder levels of farm income, cropping systems with legumes should therefore be given more research attention in NigeriaDoctor of Philosophy (PhD)
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Mkhonta, Vusumuzi Meshack. "The biology and cultural control of grass-weeds in smallholder maize cropping systems." Thesis, University of Reading, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430913.
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Monakisi, Charlotte. "N₂ fixation, plant mineral nutrition and C metabolites in cowpea/maize cropping systems." Bachelor's thesis, University of Cape Town, 2002. http://hdl.handle.net/11427/25932.
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The objective of this study was (1) quantify N₂ fixation in sole and mixed cropped cowpea, (2) To access nutrient assimilation by component species in the cropping system, and (3) to determine the effects of cropping system on C metabolites. At harvest the dry mass of both cowpea and maize were highest in sole crops. There was a significant difference in % nitrogen of maize and cowpea plants from the different cropping systems. Total nitrogen content was highest in sole cropped maize and cowpea plants with sole cowpea fixing the most N₂. δ¹⁵N values were lower for the shoots of symbiotic cowpea compared to the maize. Root δ¹⁵N values were also generally lower in cowpea than in maize. The %N derived from fixation (Ndfa) was similar for sole, intra and intercropped cowpea. However the amount of N fixed was significantly greater in sole cowpea compared to intra- and intercropped cowpea. When nutrient uptake and assimilation was assessed in the cropping system, it was found that mineral elements such as Ca, Mg, Cu, Zn and B occurred in significantly greater concentrations in the N₂-fixing legume compared to the cereal partner. However the concentration of soluble sugars and starch remained the same for both shoot and roots of cowpea and maize plants in the cropping system.
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Nandwa, Stephen Makuku. "Synchronization of nitrogen mineralization with N uptake through maize stover placements and N fertilization under continuous maize mono-cropping systems in Kenya." Thesis, University of Exeter, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262432.
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Kaluli, J. Wambua. "Water table management and cropping systems for intensive corn production." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40155.
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The use of agricultural chemicals, such as nitrogen fertilizers in corn production, often results in water pollution. This research, comprising three parts, was designed to investigate the effects of nitrogen fertilizer application rates, water table management, and corn cropping systems on drainage water quality. The first part was a field study, to investigate the impact of two cropping systems and water table management on nitrate loss through tile drainage. The considered water table treatments were free drainage, and subirrigation with target water table depths at 0.5 m or 0.75 M below the soil surface. Corn (Zea mays L.) monoculture and corn intercropped with annual ryegrass (Lolium multiflorum Lam.) were investigated. The highest annual tile drainage losses of 21.9 kg N/ha were measured in monocropped, freely draining plots. Subirrigation with a water table depth of 0.5 m reduced tile drainage loss of N by over 70%, and intercropping corn with ryegrass under free drainage reduced leaching losses by 50%.The second part of the research was a simulation study with the water quality model, DRAINMOD-N. The water quality impact of fertilizer application rate under free drainage, subirrigation and controlled drainage was evaluated. Leaching losses, denitrification and N accumulation in the soil profile were investigated. Using data obtained from the field experiment, the performance of DRAINMOD-N was evaluated. DRAINMOD-N assumes that denitrification follows first order kinetics, contrary to field measurements which showed little correlation between denitrification rate and NO$ sb3 sp-$-N concentration. Therefore, DRAINMOD-N was modified by replacing the original denitrification function with the Michaelis-Menten relationship. In so doing, denitrification is expressed as a first order process when NO$ sb3 sp-$-N concentration limits denitrification, and as a zero order process for non-limiting NO$ sb3 sp-$-N concentration.
For denitrification to be a decision making criterion of water table management, inexpensive but reliable measurement techniques are required. Thus, the purpose of the final part of this research was to formulate a technique for measuring real-time denitrification rate. Denitrification rate could be expressed as a function of soil redox potential (Eh) and temperature. Laboratory and field studies showed that factors such as soil nitrate and organic carbon had negligible effect on denitrification rate. Therefore, it can be concluded that for most agricultural soil, Eh and soil temperature will satisfactorily describe denitrification variation.
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Alemán, Freddy. "Studies on bean-maize production systems in Nicaragua /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-5788-2.pdf.
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Pachta, Christopher James. "Improving irrigated cropping systems on the high plains using crop simulation models." Thesis, Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/316.
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Anthofer, Jürgen. "The potential of Mucuna fallow for maize based cropping systems in the Forest-Savannah Transitional Zone of Ghana." Weikersheim Margraf, 2005. http://deposit.ddb.de/cgi-bin/dokserv?id=2659724&prov=M&dok_var=1&dok_ext=htm.
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Itimu, Ommar. "Nitrogen dynamics and root distribution of gliricidia sepium and senns spectabilis in maize (zea mays) based alley cropping systems in Malawi." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267581.
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D'Attilio, DeAnna Rae. "Optimizing nitrogen fertilization practices under intensive vineyard cover cropping floor management systems." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/56614.
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Under-trellis cover crops have become more prevalent in East Coast grape growing regions through either intentional planting or adoption of native vegetation, to minimize the potential for erosion and to help regulate grapevine size and vigor. These companion crops, however, have sometimes resulted in increased competition for soil nitrogen, leading to decreased vine nitrogen status and berry yeast assimilable nitrogen (YAN). The aim of this study was to determine the effects of different nitrogen fertilization methods applied at varying doses and different times, on vine and berry nitrogen parameters of cover cropped grapevines. The research described herein involved Sauvignon blanc, Merlot, and Petit Manseng grapevines (Vitis vinifera L.) subjected to different sets of nitrogen treatments, and was primarily conducted over two years. There were very few differences in pruning weights, canopy architecture, components of yield, and primary fruit chemistry amongst nitrogen treatments. Sauvignon blanc petiole nitrogen concentration, season-long chlorophyll content index (CCI) values, and berry YAN were most affected by the highest rate of soil nitrogen treatment (60 kg N/ha total split between two calcium nitrate applications at bloom and six weeks post bloom) and foliar fertilization (40 kg N/ha split over seven to nine urea applications); however, the foliar fertilization was most effective at increasing the concentration of certain individual amino acids. Petit Manseng berry YAN at harvest was increased in response to post-véraison foliar applications (10 kg N/ha split between two urea applications), corresponding to an increased concentration of nine amino acids. Merlot berry YAN, petiole nitrogen concentration, and season-long CCI values were most affected by a high rate of soil nitrogen treatment (60 kg N/ha total split between two calcium nitrate applications at bloom and six weeks post bloom) and establishing clover as the under-trellis cover crop. This study identified nitrogen treatments that improved berry nitrogen concentration and content in cover cropped sites.Master of Science
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Kambanje, Ardinesh. "Productivity and profitability of different maize varieties and cropping systems used in the smallholder sector of the Eastern Cape Province of South Africa : implication on food security." Thesis, University of Fort Hare, 2018. http://hdl.handle.net/10353/6237.
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Low maize yields in the midst of abundant arable land, favourable climatic conditions, input and financial support programs, plagues smallholder maize farming in Eastern Cape Province. These scenarios have led the province to be a net importer of maize. In essence, low production may signify a mis-match between maize varieties being promoted amongst smallholder farmers and their farming system. Thus, the main objective of the study was to investigate the productivity and profitability of different maize varieties and cropping system under smallholder agriculture in selected villages of the Eastern Cape Province of South Africa as well as, the implications posed on the household food security. The study sought to assess: (i) the productivity of different maize varieties and cropping systems, (ii) the effect of GM maize adoption on food security among smallholder farmers, (iii) the profitability of GM, conventional hybrids and OPV maize varieties produced by farmers under different agro-ecological conditions and (iv) the impact of different maize varieties and cropping systems on food security in the smallholder agriculture. A cross sectional quantitative-based survey study was carried out to obtain information from a total of 650 small holder farmers. The study was conducted in three local municipalities in Oliver Reginald (OR) Tambo District Municipality of the Eastern Cape Province of South Africa. Descriptive statistics, partial factor productivity, gross margin analysis, household food insecurity access score (HFIAS), ordinal logistic and linear regression were the analytical techniques used in establishing correlations among variables. Results obtained from the survey indicated that under mono-cropping system, Genetically Modified (GM) maize variety was highly productive with an average yield of 1.9 t/ha whilst, improved OPV maize variety was productive (with an average yield of 1.6 t/ha) under mixed cropping system. Furthermore, GM maize (GM = -R418.10), and landrace (GM = -R1 140.29) maize varieties had negative gross margins whilst, conventional hybrids (GM = R5 181.21) and improved OPV (GM = R1 457.41) were profitable. There was a significant and negative correlation between use of GM maize variety and reduction of household food insecurity. GM maize varieties, improved OPV, white maize, white as well as yellow GM maize varieties had a significant impact in reducing household food insecurity; whilst using more than one variety of maize (landraces and GMO) positively influenced household food insecurity. In light of these research findings, it is recommended that, there is need to address household food security by growing improved OPVs under a mixed cropping system and GM maize under monocropping system.
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Kwabiah, Allan B. "Management of organic resources for soil fertility improvement in low-input cropping systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ35801.pdf.
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Böhmel, Constanze. "Comparative performance of annual and perennial energy cropping systems under different management regimes." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:100-opus-2945.
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Showalter, Baylee M. "Effect of planting management factors on canola performance in high-residue cropping systems." Thesis, Kansas State University, 2016. http://hdl.handle.net/2097/34624.
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Master of ScienceDepartment of Agronomy
Kraig Roozeboom
Winter survival of canola (Brassica napus L.) is a challenge for producers using high-residue, no-tillage, or reduced tillage systems. In addition, as hybrid cultivars have become more available in recent years, this has brought about questions regarding best management practices to aid in mitigating winter survival challenges associated with high residue production systems. Overcoming production challenges will allow producers to diversify their no-till cropping systems with an oil seed crop having strong domestic demand. This research was undertaken to identify practices that could improve performance of canola in high-residue cropping systems. Two sets of experiments were conducted at twelve sites across Kansas from 2014 to 2016 to evaluate practices that could improve stand establishment, winter survival, and yield of winter canola. The objective of the first study conducted at 10 site years was to determine the effect of residue management, seeding density, and row spacing on stand establishment, winter survival, and yield. An innovative residue management system being developed by AGCO Corp. was compared to cooperating canola producers’ no-till residue management and planting methods in wheat residue. This on-farm experiment was conducted at ten environments across Kansas. AGCO treatments were 20 or 30-in row spacing and three seeding rates for a total of six treatments. Producer treatments included their preferred row spacing, seeding rate, and residue management practices. Winter survival increased by 11% to 29% as seeding rate decreased in 20-in rows at four of the five harvested environments. At Stafford and Kingman, the lowest yielding AGCO treatment produced 3.7 to 4.2-bushel acre⁻¹ more than the respective cooperator treatments. Reduced seeding rates in the AGCO system produced yields similar to or superior than the cooperator practice in all environments. Producers have been turning to planting canola in wide rows to facilitate residue management with strip tillage or planter residue management attachments. The objective of the second study conducted at three site-years was to determine the effect of seeding rate on winter survival and yield of hybrid and open-pollinated winter canola cultivars in 30-in rows. Treatments were four genotypes and five seeding rates for a total of twenty treatments. Winter survival increased with the lowest seeding rate at one of the three environments. At two of the three environments neither genotype nor seeding rate affected yield. These results indicate that seeding rates can be reduced from those typically used by canola producers in high residue, no-till or reduced tillage systems if residue can be adequately removed from the seed row. Both hybrid and open-pollinated winter canola cultivars responded similarly to seeding rate in 30-in rows in these experiments, indicating that similar seeding rates could be used for each type of cultivar. Management practices such as, narrow row spacing, reducing seeding rates, and adequately managing residue at planting may result in small improvements to establishment, winter survival and yield.
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Jowkin, Vishwanath. "Impact of tillage management and landscape on nitrogen availability in cereal-fallow cropping systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq23943.pdf.
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Ramoroka, Mokgadi Mizen. "Grain yield, gravimetric moisture content, dry matter accumulation and chlorophyll production in maize-legume intercrop under minimum and conventional tillage systems." Thesis, University of Limpopo (Turfloop Campus), 2008. http://hdl.handle.net/10386/639.
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Thesis (M.Sc. (Agriculture)) --University of Limpopo, 2008Maize is a dominant crop in smallholder farming systems in the Limpopo province of South Africa, generally cultivated as intercrop with grain legumes. The major constraint in this cropping system is inadequate soil moisture during the growing season, which also limits nutrient availability to the component crops. The minimum tillage system has been reported to improve soil moisture availability on farmers’ fields but this has not yet been verified in an intercropping system in the province. The objective of this study was to quantify grain yield and chlorophyll production of intercropped maize, and to assess seasonal moisture availability under minimum tillage (MT) and conventional tillage (CT) systems. Dryland field experiments were conducted at two locations in the province namely, farmer’s field at Dalmada in 2002/2003 and 2003/2004 growing seasons and at the University of Limpopo Experimental farm at Syferkuil during the 2003/2004. The experimental design was a randomized complete block in split plot arrangement at all locations and seasons. Tillage systems consisting of conventional tillage and minimum tillage were the main plot treatments, whereas five different cropping systems namely, sole maize, and maize intercrop with cowpea (variety, Bechuana White), cowpea (variety, Agripers), Lablab bean (variety, Rongai) and Velvet bean were assigned as sub-plot treatments. Maize grain yield in 2002/2003 at Dalmada was significantly lower (357 kg/ha) under CT relative to 755kg/ha under MT. In 2003/2004 at Dalmada, grain yields under the two systems were similar, where as at Syferkuil, 15% higher grain yield results was obtained under MT. Minimum tillage systems resulted in higher number of maize cobs per plant at Dalmada in both growing seasons and weight per cob was higher under MT at both locations and seasons. At Dalmada, significantly higher soil moisture was recorded under the MT relative to the CT depending on depth and sampling dates. Chlorophyll content of the youngest fully expanded leaves of maize was generally higher under MT than CT, but this was observed only at the later stages of plant growth. The results also showed that the rate of senescence (reduced chlorophyll content in older leaves) was higher in maize plants grown under CT relative to those under MT. The minimum tillage system has shown the potential of being a superior system for dryland maize production, but further research involving additional locations is required to ascertain this fact.
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Mishiyi, Sibongile Gift. "Nodulation, dry matter accumulation and grain yield of cowpea and lablab varieties under sole and intercropping system with maize." Thesis, University of Limpopo (Turfloop Campus), 2006. http://hdl.handle.net/10386/694.
Full textAbstract:
Thesis (M.Sc. (Agronomy )) --University of Limpopo, 2007Intercropping is the growing of two or more crops simultaneously on the same field, and it is a common traditional practice among resource-poor farmers throughout the Limpopo Province of South Africa. Field studies were conducted at two locations in the province namely, the University of Limpopo experimental farm at Syferkuil, and a farmer’s field at Dalmada during the 2002/2003 growing season, to determine patterns of nodulation in cowpea and lablab varieties under sole culture and in an intercropping system with maize, variety SNK2147 and also to assess biomass accumulation and grain yielding abilities of the component crops in the system. The experiments were established as a randomized complete block design with three replications at each location. Treatments examined were sole maize, two cowpea cultivars: Bechuana white and Glenda; two lablab cultivars, Rongai and Common. The legumes were intercropped alternately within 90 cm inter-row spacing of maize, thus creating a distance of 45 cm between the maize and the legume rows. Cropping system had no effect on cowpea grain yield at Syferkuil, but at Dalmada cowpea yield was reduced. Maize grain yield was significantly affected by the cropping system at both Syferkuil and Dalmada. At both locations, the yields of all the intercropped maize were lower than those of the sole crop maize. The dry matter production of different cropping systems was generally similar during the different sampling dates.
the National Research Foundation,and the Gauteng Department of Agriculture Conservation and Environment
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Sebetha, Erick Tshivetsi. "Evaluation of yield and protein content ot two cowpea cultivars grown under diferent management practices." Thesis, University of Limpopo, 2009. http://hdl.handle.net/10386/579.
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Thesis (M.Sc. (Horticulture)) --University of Limpopo, 2009Field experiments were conducted at the University of Limpopo experimental farm, Syferkuil during 2005/06 and 2006/07 production seasons. This was initiated to examine the effect of leaf removal on cowpea biomass, protein content and grain yield under sole and binary cultures. Treatments consisted of cowpea varieties (Pan 311 and Red caloona), cropping systems (sole and intercropping) and cowpea-leaf pruning regimes (pruning and un-pruned). Sweet corn was planted, as a component crop in the intercropped plots while sole sweet corn plot was included as a treatment. All treatment combinations were laid out as Randomize complete block design (RCBD) with four replicates. Supplementary irrigation was carried out during the plant growth period. Fully expanded leaves were harvested once on all cowpea plants in the two middle rows from designated plots at seven weeks after planting for each year. Growth and yield data were collected from component crops during the course of the trial while the protein content of harvested leaves and immature pods as well as the different cowpea plant parts at harvest were determined. Results of the study revealed that leaves of cowpea variety, Pan 311 harvested prior to the reproductive stage had significantly higher protein content than those of Red caloona. Protein content of immature Pan 311 pods had higher (18.8 to 25.1%) than Red caloona (17.9 to 20.7%) during both planting seasons. The percent protein content of cowpea stem obtained at harvest for Pan 311 varied between 9.3 and 9.4%, and between 9.9 and 12.3% for Red caloona during both planting seasons. Grain yield obtained for Pan 311 and Red caloona were 1703.7 kg ha-1 and 1479.8 kg ha-1, respectively during 2005/06 and 1290.7 kg ha-1 and 511.7 kg ha-1 respectively during 2006/07 planting seasons. Sweet corn intercropped with Red caloona during both planting seasons had higher average grain yield than when intercropped with Pan 311. Although intercropping decreased the partial land equivalent ratio (LER) value of individual component crops, the combined LER values of between 1.1 and 2.3 under intercrop for the different treatment combinations implies that the practice is advantageous. The results of post harvest soil analyses revealed that topsoil has the pH value of 7.11-7.29 indicating neutral soil while subsoil pH value of 6.27-6.91 indicated slightly acidic to neutral soil during both planting seasons. Based on the findings of this study, cowpea variety Pan 311 can be recommended as a better vegetable crop than Red caloona since it has higher leaf and immature pod protein content. It also had higher grain yield than Red caloona when intercropped with sweet corn. Sweet corn had high grain yield when intercropped with Red caloona than when intercropped with Pan 311. Keywords: Cropping systems, protein content, grain yields, leaf pruning and cowpea.
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Chege, Ayub Getheyo. "Management of plant nutrients in smallholder farming systems of Western Kenya." Thesis, University of Exeter, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341197.
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Izard, Erica Jean. "Seeking sustainability for organic cropping systems in the Northern Great Plains: legume green manure management strategies." Thesis, Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/izard/IzardE0807.pdf.
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Janz, Baldur [Verfasser], Ralf [Akademischer Betreuer] Kiese, and Heinz [Akademischer Betreuer] Rennenberg. "Greenhouse gas footprint of organic amendments and water management in rice cropping systems in Southeast Asia." Freiburg : Universität, 2019. http://d-nb.info/1209052229/34.
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Santos, Denis Medeiros dos. "Weed management in direct-seeded and transplanted maize grown for grain in Southern England." Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262248.
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Wang, ShuHui. "Cultivation practices, maize and soybean productivity and soil properties on fragile slopes in Yunnan Province, China." Thesis, University of Wolverhampton, 2003. http://hdl.handle.net/2436/116735.
Full textAbstract:
Sustainable agriculture in China is highly threatened by rapid urbanization, land degradation and high population pressure. Yunnan Province, south-west China, is 94% mountainous and lacks flat land. Food shortages and inappropriate cultivation have led to intensive cultivation of steep, marginal and fragile land and have increased soil erosion. To curb this situation and assist with poverty alleviation, it is crucial to develop more productive and sustainable cropping systems. An experiment was conducted on sloping areas from 1999 to 2001 in Wang Jia Catchment, Yunnan Province. The project aim was to evaluate the effects of five selected cultivation practices on maize productivity and soil properties. The treatments were: (1) downslope cultivation without mulch, (2) contour cultivation without mulch, (3) contour cultivation with polythene mulch, (4) contour cultivation with polythene and wheat straw mulch (Integrated Contour with Plastic and Straw Mulch Treatment, INCOPLAST) and (5) contour cultivation with polythene mulch and intercropping, wide and narrow row spacing, with soybean in wide row spacing. Crop growth parameters and soil physical properties were measured throughout the cropping seasons. Considering three years data, contour cultivation with polythene mulch generally increased soil temperature by a mean of 1-2°C. The polythene retained considerably more soil moisture during dry weather. However, during wet weather, polythene prevented rainfall directly falling on the soil, which led to less soil moisture content. The soil temperature and moisture regimes under polythene mulch made plants grow faster and canopies develop well, leading to higher final yields. The benefit of polythene was 33-54% more yield than downslope cultivation without mulch treatment, over three seasons. Contour cultivation plus polythene and straw mulch retained significantly higher soil moisture levels. The yield of this treatment in 1999 was ranked second, but in 2000 it had the highest yield and in 2001 it was also more effective than contour cultivation with polythene mulch treatment. Contour cultivation with polythene mulch and intercropping improved maize yield. The soybean harvest also contributed to net income, the crop had a similar function to straw mulch and increased N availability. Contour cultivation increased yields over the range 7.2-11.2% over three seasons compared with downslope cultivation, equivalent to ~500-1000 kg per hectare more grain produced. There were few clear trends in soil properties over the 1999-2001 period. However, N concentrations increased in the contour cultivation with polythene mulch and intercropping treatment. Both contour cultivation with polythene and straw mulch and contour cultivation with polythene mulch and intercropping gave apparent increases in total K, probably resulting from both decayed straw and decomposed soybean leaves. In terms of simple cost-benefit evaluation, downslope cultivation had the lowest input and output, while contour cultivation had a similar input, but a higher output. Contour cultivation with polythene had the highest net return. Contour cultivation with polythene and straw had a high output but did not give a higher net return than contour cultivation with polythene. Contour cultivation with polythene mulch and intercropping generally had the highest input and output and could give a higher net return than contour cultivation with polythene when the soybean harvest was successful, but over three years this treatment had the greatest risk from crop failure. It is recommended that replacing downslope cultivation with contour cultivation can increase crop yields and this simple action could contribute to the development of more sustainable cropping systems in Yunnan. Polythene mulch achieved higher maize yields but its environmental impact requires further study. It is considered that contour cultivation with polythene and straw mulch or soybean intercropping could contribute towards more productive and sustainable cropping systems where soil conservation is high priority. The technique could assist with long-term soil, water and nutrient conservation and improved crop productivity.
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Pelletier, Bernard 1964. "Management practices, soil quality and maize yield in smallholder farming systems of central Malawi." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37809.
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The effect of management practices used by smallholder farmers to improve soil quality and increase maize yield was examined in an 80 ha. micro-watershed of central Malawi. Because of the complexity inherent in smallholder farming systems, this research proposed the combination of participatory methods with analytical techniques developed in field ecology, such as multivariate and spatial analysis. During a Participatory Rural Appraisal (PRA), farmers identified factors potentially influencing soil quality and maize yield. One hundred and seventy-six (176) plots were located in twenty-nine (29) fields and characterized for management practices and biophysical characteristics. Soil samples were collected at each plot and analysed for a suite of properties. The maize yield was measured for both 1996--97 and 1997--98 seasons. A formal survey was used to gather information on household characteristics. Results showed that management practices that were promoted by a previous extension project, such as alley cropping and the planting of grass on contour ridges, were strongly correlated and found mainly in fields located closer to house compounds. Farmers with a higher proportion of their land under wetland gardens tended to use less agroforestry. Food security was associated with households that were able to purchase inorganic fertilizers, had larger landholding size, and owned livestock and woodlots. The effect of management practices on maize yield and soil quality was partially confounded with characteristics of the plot, such as slope, degradation level, number of years under cultivation or pest damage. Higher maize yield was observed in plots that were better managed, as expressed by the combination of different management practices, lower pest incidence, fewer erosion signs and higher soil fertility. Some positive effects of alley cropping on soil quality were observed in plots that were cultivated for a longer period and located on flatter land. This study demo
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Jäck, Ortrud [Verfasser], and Roland [Akademischer Betreuer] Gerhards. "Integrated weed management in intensive cropping systems : towards reduction of herbicide input / Ortrud Jäck. Betreuer: Roland Gerhards." Hohenheim : Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim, 2016. http://d-nb.info/110718116X/34.
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Zheng, Jinsen. "NITROGEN MANAGEMENT IN MAIZE-BASED SYSTEMS OF THE TANZANIAN HIGHLANDS: BALANCING FOOD AND ENVIRONMENTAL OBJECTIVES." Kyoto University, 2019. http://hdl.handle.net/2433/236626.
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付記する学位プログラム名: グローバル生存学大学院連携プログラムKyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第21465号
農博第2308号
新制||農||1064(附属図書館)
学位論文||H31||N5160(農学部図書室)
京都大学大学院農学研究科地域環境科学専攻
(主査)教授 舟川 晋也, 教授 間藤 徹, 教授 縄田 栄治
学位規則第4条第1項該当
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Vu, Dinh Tuan [Verfasser], and Georg [Akademischer Betreuer] Cadisch. "Soil conservation methods and their impact on nitrogen cycling and competition in maize cropping systems on steep slopes in Northwest Vietnam / Tuan Vu Dinh. Betreuer: Georg Cadisch." Hohenheim : Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim, 2016. http://d-nb.info/108171624X/34.
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Mwangi, James Maina [Verfasser]. "Resistance based integrated pest management strategy for Globodera rostochiensis and Globodera pallida in potato cropping systems / James Maina Mwangi." Kassel : Universitätsbibliothek Kassel, 2019. http://d-nb.info/1231409576/34.
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Nishigaki, Tomohiro. "Improvement of Water- and Nutrient-Use Efficiency with Optimum Agricultural Management Practices in Upland Cropping Systems in Morogoro, Tanzania." Kyoto University, 2017. http://hdl.handle.net/2433/228243.
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Gruber, Helga [Verfasser], Martin Akademischer Betreuer] Müller, Heinrich H. D. [Akademischer Betreuer] [Meyer, and Karl [Akademischer Betreuer] Kramer. "Surveillance of Cry1Ab protein and cry1Ab DNA in liquid manure, soil and agricultural crops under Bt-maize cropping and slurry management of cows fed Bt-maize (MON810) / Helga Gruber. Gutachter: Karl Kramer. Betreuer: Martin Müller ; Heinrich H. D. Meyer." München : Universitätsbibliothek der TU München, 2011. http://d-nb.info/1019590017/34.
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Ndabamenya, Telesphore. "Plant density management and its effect on the productivity of low input East African highland banana (Musa spp.)-based cropping systems." Thesis, University of Pretoria, 2013. http://hdl.handle.net/2263/40272.
Full textAbstract:
East African highland bananas (Musa spp., AAA-EA genome group) are a major staple and
income-generating fruit crop in the highlands of eastern and central Africa, grown across the
countries of the Great Lakes region (i.e. Rwanda, Burundi, Uganda, eastern Democratic
Republic of Congo and North-West Tanzania). Despite its importance, farmers and
researchers are reporting that yields are declining, most notably in areas with low soil
fertility. Although numerous studies have been conducted on yield constraints of bananas in
the East African highland region, there is virtually no understanding of the impact of plant
density management on the yields of these low-input banana systems. The productivity and
profitability of various plant densities was studied in contrasting agro-ecological sites of
Rwanda (Ruhengeri, Rusizi, Karongi, Butare, Ruhango, Kibungo and Bugesera), that differed
distinctly in terms of altitude (1400-1960 m a.s.l), temperature (17-20°C), annual rainfall
(950-1400 mm yr-1) and soil types (Nitisols, Ferralsols, Acrisols and Andosols). Under those
cropping systems, the plant density is one management factor that resource poor farmers have
some control over.
An on-farm survey was conducted in all sites to determine the influence of climatic and
edaphic factors on variations in on-farm plant density practices and bunch mass. In addition,
three researcher-managed banana density experiments were conducted in contrasting agroecological
sites (Kibungo low rainfall with medium soil fertility, Rubona high rainfall with
low soil fertility and Ruhengeri high rainfall with high soil fertility) to (i) investigate the
influence of plant density on the vegetative growth and yield parameters of AAA-EA bananas
for typical highland agro-ecological zones, (ii) to assess the effect of plant density on nutrient
deficiencies and imbalances, and (iii) to assess the magnitude and variability of nutrient
depletion in the smallholder banana systems that are characterized by low external input use.
Three different local EA highland banana varieties (i.e. “Ingaju”-cooking type, “Injagi”-
cooking type, “Intuntu”-beer type) were each planted at five different plant densities (plants
ha-1) of 1428, 2500, 3333, 4444 and 5000. Agronomic data (growth and yield traits) were
collected over two cropping cycles (plant and ratoon crops). Soil, plant and climate data were
also collected. Approaches such as compositional nutrient diagnosis (CND), boundary line
functions and yield gap analysis were used to quantify the contribution of each identified
yield limiting factor to yield gap. A first order magnitude of nutrient depletion was
determined using partial nutrient balance calculations.
Plant density positively correlated with water supply (i.e. difference between rainfall and
evapotranspirative demand of bananas), with highest plant densities (>1500 mats ha-1) found
in high rainfall areas (>1200 mm yr-1) with water surplus (218-508 mm yr-1) and lowest plant
densities (1000-1400 mats ha-1) found in lower rainfall areas (1000-1200 mm yr-1) with water
deficit (from -223 to -119 mm yr-1). Bunch masses were significantly higher at the lowest
plant densities (18.1-20.8 kg fresh mass plant-1) when compared to the highest plant densities
(14.7-15.5 kg). Lower soil and banana leaf nutrient contents were observed on weathered
soils (Acrisols) and were associated with smaller bunch mass in comparison to fertile soils
(Andosols, Nitisols). Farmers tended to reduce mat densities (i) if they wanted to intercrop,
and (ii) to increase bunch mass to adapt to market preferences for large bunches. The plant
densities generally recommended by extension bodies (3 × 3 or 2 × 3 m; i.e. 1111 and 1666
mats ha-1, respectively) are seldom practiced by farmers, nor do they seem to be very
appropriate from an agronomic or economic perspective.
Per hectare bunch and above ground biomass yields increased with increasing plant density,
but maximum yield strongly depended on agro-ecological site. Bunch yields of beer bananas continued to increase with density, but maximum yields for the cooking cultivars were
observed at 4444 plants ha-1 at Kibungo and Rubona, whereas yields continued to increase
linearly beyond this level at Ruhengeri. Relationships between bunch yield, the total above
ground dry matter yields and soil chemical properties suggest that nutrient deficiencies were
larger at Kibungo (i.e. notably K) and Rubona (i.e. K, P, Ca, Mg) when compared with
Ruhengeri. With increasing densities, leaf area index (LAI) continues to increase up to a
value of 4 with 95% of photosynthetic active radiation (PAR) intercepted by the crop canopy.
This suggests that further density and LAI increases would probably have little additional
positive effect on total per hectare production.
Compositional nutrient diagnosis (CND) indices showed that K, Mg and P were the most
deficient elements in areas with low inherent soil fertility (Kibungo and Rubona) compared
with relatively fertile areas (Ruhengeri). The boundary line functions and yield gap analysis
also confirmed that K was the most limiting factor, contributing to an expected yield gap of
55.3% at Kibungo, while P and Mg contributed to a 35% yield gap at Rubona. An increase in plant density resulted in an increase in average yield gap from 45.6 % to 70.2% at Kibungo,
whilst average yield gap decreased significantly from 47.5% to 30.2% at Rubona, and 76.6 to
53.7% at Ruhengeri. Nutrient uptake increased with plant density. Partial N and K balances
(kg ha-1 yr-1) were estimated to be strongly negative at Rubona and Ruhengeri, while Ca and
Mg were positive at Kibungo and Ruhengeri, but negative at Rubona. The results of this
study indicate that, generally, soil fertility is a more limiting factor than water, but both CND
norms and boundary line analysis showed that expected yield gaps seem to be high for plant
density due to low inherent soil fertility. Partial nutrient balances provide a first order
magnitude of nutrient depletion. Nutrient mining is significant, particularly for K. The current
extraction rates will not allow farmers to sustain their yields, and options should be
developed to improve the productivity of EAH banana cropping systems. The limited
availability of manure and inorganic fertilizers is a real threat to the food and income security role that banana production plays in smallholder systems.
In summary, the results from this study suggest the optimal density for bananas depends on
water availability, soil fertility and cultivar. The agronomic optimal plant density is lower (<
4444 plants ha-1) in low rainfall (< 1000 mm yr-1) and less fertile areas, but seems to be
higher (> 5000 plants ha-1) in areas with high fertility, which receive high rainfall (> 1300
mm yr-1). Improved plant density management can serve as an important entry point for
resource poor farmers to maximize yield potential of EAH bananas in the various production
zones. Blanket density recommendations do not make sense. While farmers can significantly
improve their banana production, increased densities will put significant additional stress on
limited nutrient resources, and region-specific integrated soil fertility recommendations
should be developed and adopted to ensure sustained improvements of banana production and
smallholder livelihoods.Thesis (PhD)--University of Pretoria, 2013.
gm2014
Plant Production and Soil Science
unrestricted
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Kloß, Sebastian. "Simulation-Optimization of the Management of Sensor-Based Deficit Irrigation Systems." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-188762.
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Current research concentrates on ways to investigate and improve water productivity (WP), as agriculture is today’s predominant freshwater consumer, averaging at 70% and reaching up to 93% in some regions. A growing world population will require more food and thus more water for cultivation. Regions that are already affected by physical water scarcity and which depend on irrigation for growing crops will face even greater challenges regarding their water supply. Other problems in such regions are a variable water supply, inefficient irrigation practices, and over-pumping of available groundwater resources with other adverse effects on the ecosystem. To face those challenges, strategies are needed that use the available water resources more efficiently and allow farming in a more sustainable way.
This work focused on the management of sensor-based deficit irrigation (DI) systems and improvements of WP through a combined approach of simulation-optimization and irrigation experiments. In order to improve irrigation control, a new sensor called pF-meter was employed, which extended the measurement range of the commonly used tensiometers from pF 2.9 to pF 7.
The following research questions were raised: (i) Is this approach a suitable strategy to improve WP; (ii) Is the sensor for irrigation control suitable; (iii) Which crop growth models are suitable to be part of that approach; and (iv) Can the combined application with experiments prove an increase of WP?
The stochastic simulation-optimization approach allowed deriving parameter values for an optimal irrigation control for sensor-based full and deficit irrigation strategies. Objective was to achieve high WP with high reliability. Parameters for irrigation control included irrigation thresholds of soil-water potentials because of the working principle behind plant transpiration where pressure gradients are transmitted from the air through the plant and into the root zone.
Optimal parameter values for full and deficit irrigation strategies were tested in irrigation experiments in containers in a vegetation hall with drip irrigated maize and compared to schedule-based irrigation strategies with regard to WP and water consumption. Observation data from one of the treatments was used afterwards in a simulation study to systematically investigate the parameters for implementing effective setups of DI systems.
The combination of simulation-optimization and irrigation experiments proved to be a suitable approach for investigating and improving WP, as well as for deriving optimal parameter values of different irrigation strategies. This was verified in the irrigation experiment and shown through overall high WP, equally high WP between deficit and full irrigation strategies, and achieved water savings. Irrigation thresholds beyond the measurement range of tensiometers are feasible and applicable. The pF-meter performed satisfactorily and is a promising candidate for irrigation control. Suitable crop models for being part of this approach were found and their properties formulated. Factors that define the behavior of DI systems regarding WP and water consumption were investigated and assessed.
This research allowed for drawing the first conclusions about the potential range of operations of sensor-based DI systems for achieving high WP with high reliability through its systematical investigation of such systems. However, this study needs validation and is therefore limited with regard to exact values of derived thresholds.
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Ndemah, Rose Ngeh. "Towards an integrated crop management strategy for the African stalk borer, Busseola fusca (Fuller) (Lepidoptera: Noctuidae) in maize systems in Cameroon." [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=95820554X.
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Odhiambo, George Duncan. "Studies on witchweed [Striga hermonthica (Del.) benth] seed longevity and maize [Zea mays L.] productivity under different management systems in Kenya." Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244943.
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Mühlig-Versen, Bernhard. "Effects of crop residue management, phosphorus application and molybdenum supply on yield and nutrient uptake of pearl millet, cowpea and groundnut in Sahelian cropping systems /." Beuren : Grauer, 2001. http://opac.nebis.ch/cgi-bin/showAbstract.pl?u20=3861863723.
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Ahnström, Johan. "Farmland biodiversity - in the hands and minds of farmers : effects of landscape structure, management and the farmer's interest in nature /." Uppsala : Dept. of Ecology, Swedish University of Agricultural Sciences, 2009. http://epsilon.slu.se/200934.pdf.
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Engelbrecht, Emil Ettiene. "Nematode (Phylum Nematoda) community assemblages : a tool to implement environmentally–sound management strategies for root–knot nematodes (Meloidogyne spp.) in potato–based cropping systems / Emil Ettiene Engelbrecht." Thesis, North-West University, 2012. http://hdl.handle.net/10394/8095.
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those special or additional educational needs and goals that would enable students to fulfil their future roles in their communities and beyond. It is also argued that the mini–education systems of non–governmental institutions could make a major contribution to solve these problems. In particular, the analysis and discussion of the mini–education system of the Foundation for Cross–Cultural Education, has demonstrated that the mini–education system of a private educational initiative can make a substantial contribution towards the educational upliftment of a community in a particular rural area.
The study provides an instrument to plan and facilitate the mini–education systems of private education initiatives working in developing communities to effect the required transformational development. To confer advice to these private educational initiatives in SSA and to address the current global concern regarding the quality of formal education, the study adapted Steyn et al.’s (2002) framework for strategic education system planning. The adapted framework guidelines can be used to increase the efficiency of all the components and elements of the particular mini–education systems functioning in developing communities. The particular strategic framework was also applied to identify and describe the needs and determinants influencing quality education in developing communities in Sub–Saharan Africa in general.
It was also found that the specific framework for strategic planning was applicable to position the mini–education system, of a particular education private initiative, in such a way that it can effectively provide in the real education needs of a particular developing community. The framework also provides valuable guidelines to educational investors, as private initiatives, and national governments that wish to integrate their education provisioning in order to improve the quality of formal education provision in SSA.Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.
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Atadja, Franklin Komla. "Sustainability Challenges for Maize and Cassava Farmers in Amankwakrom Subdistrict, Ghana." Thesis, Walden University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10243184.
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Agricultural system in Ghana underperformed because of limited financing, which constrained some small-scale maize and cassava farmers. The purpose of this case study design was to explore the methods that some small-scale maize and cassava farmers in Amankwakrom Subdistrict used in obtaining farm financing. Two themes from the literature review were a lack of collateral for small-scale farm financing and the small-scale farmers cooperative associations? role in farm financing. Regional-scale management sustainability index formed the conceptual framework for this study. Data collection included semistructured face-to-face interviews with 8 fluent English speaking small-scale maize and cassava farmers who have obtained farm financing in the previous years. Using the Microsoft Excel and Non-numerical unstructured data indexing and theorizing software program for data analysis method, 3 major themes emerged: the farmer?s membership benefits of working in cooperative associations; farmer?s ability to provide the collateral requirements for the financial institutions; and farmer?s good loan repayment history. The study findings indicated that some small-scale maize and cassava farmers obtained farm loans because they used the cooperative associations as their collateral assets in order to satisfy for the requirements of the financial institutions. Social implications include the potential to guide the small-scale maize and cassava farmers to access farm credits to use in expanding their farm sizes. Expansion in farm sizes may result in more maize and cassava production that can help eliminate hunger and reduce poverty in the Amankwakrom Subdistrict of Ghana.
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Wade, Jordon. "Soil Health and Nutrient Dynamics in Agroecosystems of the Midwestern US." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555334900543422.
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Strachan, Brian Douglas. "The design, implementation and assessing of an agroecological cropping system by rural KwaZulu-Natal households : its effect on their diet and food security." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86234.
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Thesis(MPhil)--Stellenbosch University, 2014ENGLISH ABSTRACT: This thesis documents a Participatory Action Research (PAR) project conducted from 2011 to 2013 in a rural communal area in southern KwaZulu-Natal, South Africa. The area is a microcosm of the global environmental and socio-economic polycrisis; with adult unemployment at 50 percent, 73 percent female-headed households, heavy dependence on government social grants and a food system reliant on purchased food. Eight, mainly female-headed households (the co-researchers), assisted by the student researcher, implemented and assessed a cropping system, designed on agroecological principles, on their abandoned garden plots. The objective was to grow culturally acceptable food crops to supplement their household diets and positively affect their food security. The student researcher provided the necessary infrastructure, including goat-proof plot fences, hand tools, a grain hammermill, seed, and fertiliser. The literature review, which also used early 1900’s photographs and contemporary isiZulu language as evidence, revealed the agroecological basis of pre-colonial agriculture. However, colonial and apartheid influences destroyed this knowledge base. The cropping system design utilized practices from this pre-colonial era combined with current agroecological techniques. The agroecological techniques employed on the plots included non-inversion tillage of planting pits using garden forks, precision placement of phosphate fertiliser and animal manures, open pollinated seeds, east-west orientated strip cropping, soil surface mulches, crop rotations including legumes and the use of chickens to control pests. Dryland crops included maize, beans, sweet potatoes, and butternuts, with small trial vegetable patches on some plots. The research identified a method to calculate the planting frequency of these vegetables to ensure a constant annual supply, however further research is needed. The dryland crops supplemented household diets between harvests. The formation of structured groups amongst the households proved vital to the success of the cropping system, providing mutual labour assistance, shared decision-making, building knowledge and moral support. The importance of dialogue and trust, reinforced by the student researcher’s ability to communicate in isiZulu with the co-researchers, formed the basis of both the PAR, and Focus Group Discussions(FGD), used to qualitative assess the cropping system. During these, the households reported a good understanding of the agroecological principles of the cropping system, a willingness to continue with it post research, and positive benefits, including better health, and money saved on food purchases, redirected to improve their asset base. The World Food Programme (2008) Food Consumption Score Analysis Method (FCS), modified to show the percentage contribution of homegrown food to the FCS, provided the quantitative assessment of the cropping system. The FCS scores rose during the research, with homegrown food contributing over a third of the FCS at times. The co-researchers suggested instituting group ‘stokvels’1to finance inputs and maintain infrastructure post research. The financial implications of these ‘stokvels’ was calculated. Due to the initial success of the PAR, the research recommends a method to extend the cropping system to more households, utilizing state finance to provide the infrastructure, and the co-researchers imparting technical knowledge through farmer-to-farmer extension.
AFRIKAANSE OPSOMMING: In hierdie tesis word verslag gedoen van ’n deelnemende aksienavorsingsprojek wat van 2011 tot 2013 in ’n landelike dorpsgebied in die suide van KwaZulu-Natal, Suid-Afrika, uitgevoer is. Die gebied is ’n mikrokosmos van die wêreldwye omgewings- en sosio-ekonomiese polikrisis, met volwasse werkloosheid op 50%, 73% huishoudings met vroue aan die hoof, swaar afhanklikheid van die staat se maatskaplike toelae en ’n voedselstelsel wat van gekoopte kos afhanklik is. In die studie het agt huishoudings, wat hoofsaaklik vroue aan die hoof het (die medenavorsers), met behulp van die studentenavorser, ’n verbouingstelsel, wat op agro-ekologiese beginsels gegrond is, op hul verlate tuingrond geïmplementeer en geassesseer. Die doel was om kultureel aanvaarbare gewasse te verbou om hul huishoudelike dieet aan te vul en hul voedselsekerheid positief te beïnvloed. Die studentenavorser het die nodige infrastruktuur verskaf, met inbegrip van bokbestande omheining, handgereedskap, ’n graanhamermeul, saad en kunsmis. Die literatuurstudie, waarin foto’s uit die 1900’s en moderne Zoeloe as bewyse gebruik is, toon die agro-ekologiese grondslag van prekoloniale landbou. Koloniale en apartheidsinvloede het egter hierdie kennisbasis vernietig. Die verbouingstelselontwerp was gegrond op praktyke uit hierdie prekoloniale era gekombineer met moderne agro-ekologiese tegnieke. Hierdie tegnieke het ingesluit nie-inversie-grondbewerking van plantgate met gebruik van tuinvurke, presisieplasing van fosfaatkunsmis en dieremis, oop bestuifde sade, oos–wes-georiënteerde strookverbouing, grondoppervlak-deklae, wisselbou met onder andere peulgewasse en die gebruik van hoenders om peste te beheer. Droëland-gewasse het ingesluit mielies, bone, soetpatats en botterskorsies, met klein toetsgroenteakkers op sommige stukke grond. ’n Metode is in die navorsing geïdentifiseer om te bepaal hoe gereeld hierdie groente geplant moet word om ’n konstante jaarlikse voorraad te verseker. Verdere navorsing is egter nodig. Die droëland-gewasse het huishoudelike diëte tussen oeste aangevul. Die vorming van gestruktureerde groepe onder die huishoudings het noodsaaklik geblyk te wees vir die sukses van die verbouingstelsel, waardeur wedersydse hulp met arbeid, gedeelde besluitneming, die bou van kennis en morele ondersteuning gebied is. Die belangrikheid van dialoog en vertroue, wat versterk is deur die studentenavorser se vermoë om in Zoeloe met die medenavorsers te kommunikeer, het die grondslag gevorm van die deelnemende aksienavorsingsprojek asook die fokusgroeponderhoude, wat gebruik is om die verbouingstelsel kwalitatief te assesseer. In hierdie onderhoude het die huishoudings verslag gedoen van hul grondige begrip van die agro-ekologiese beginsels van die verbouingstelsel, hul gewilligheid om ná die navorsing daarmee voort te gaan, asook die voordele wat dit bied, soos beter gesondheid en geld wat op voedselaankope gespaar is, wat heraangewend is om hul batebasis te verbeter. Die Wêreldvoedingsprogram (2008) se Food Consumption Score- (FCS-)ontledingsmetode, wat aangepas is om die persentasie bydrae van selfgekweekte voedsel tot die FCS aan te toon, is gebruik vir die kwantitatiewe assessering van die verbouingstelsel. Die FCS-tellings het tydens die navorsing toegeneem, met selfgekweekte voedsel wat by tye tot meer as ’n derde tot die FCS bygedra het. Die medenavorsers het voorstel dat ’n stokvel gestig word om insette te finansier en die infrastruktuur ná die navorsing in stand te hou. Die finansiële implikasies van hierdie stokvel is bereken. Op grond van die aanvanklike sukses van die deelnemende aksienavorsingsprojek stel die navorser ’n metode voor om die verbouingstelsel na meer huishoudings uit te brei met behulp van staatsfinansiering om die infrastruktuur te verskaf asook die oordrag van die medenavorsers se tegniese kennis na ander boere.
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Andrade, Juliano Gomes de. "Perdas de água por evaporação de um solo cultivado com milho nos sistemas de plantio direto e convencional." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/5481.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorWorldwide, the agricultural sector is the largest consumer of water, reaching about 69% of total water derived from rivers, lakes and underground aquifers. Because of this huge consumption of water by agriculture and the scarcity of water in various parts of the world there is a social and environmental pressure very big, mainly on irrigated agriculture in order to improve the efficiency of the use of water. This study aimed to quantify the loss of water from the soil by evaporation, in the early stages of development of the corn crop sown in cultivation from no-tillage system and conventional tillage. The work was developed in Experimental Area of the Department of Rural Engineering of the Federal University of Santa Maria (UFSM), RS. The experiment was conducted in the period from October 28, 2006 to December 10, 2006 and consisted of four treatments: (i) direct maize sowing in bare soil (PD0), (ii) direct sowing of corn with 3,0 Mg ha-1 of straw on the soil surface (PD3), (iii) direct sowing of corn with 6,0 Mg ha-1 of straw on the soil surface (PD6), and (iv) conventional tillage of the soil without coverage of straw on the surface (PC). The loss of water from the soil were determined in four cycles of dry soil during the first 38 days after the emergence of culture, holding up the water balance in soil layers from 0 to 10 cm and 10 to 30 cm, from data of volumetric soil moisture determined with a TDR at intervals of 15 minutes. It was also determined, for the first cycle of drying soil coefficients of evaporation(K) and reducing of water evaporation from the soil (Kr), as the methodology of Kc Dual. For the short duration of the cycles of drying of the soil, growth and development of plants were not affected by the system of cultivation of the soil in the early stages of development of the corn crop. In layer from 0 to 10 cm depth for the first cycle of drying of the soil, 3,0 Mg ha-1 of straw on the surface provided a reduction in the loss of water by evaporation of 24,6% and 19,9% in relation to the PC and PD0, respectively. With 6.0 Mg ha-1 of straw, the reduction was 50,7% and 47,6%, respectively. In the first 30 cm of the soil profile, the reduction in losses of water was 18.2% and 23% respectively to 3.0 Mg ha-1 of straw. Increasing to 6.0 Mg ha-1 reduction was 38,3% and 42,0% respectively. With the growth of culture, the increase in the loss of water in the soil was due to the bigger development of plants with increasing participation of transpiration in water consumption by culture, by shading the surface at the higher leaf area index of the plants. Treatments with PC and PD0 show Ke higher, reaching 1,32 and 1,17, respectively. With the presence of straw, the maximum value of K was reduced to approximately 50% compared with the treatments without straw on the surface reaching values of 0,70 and 0,44, respectively, when EToac was 10,0 mm. The treatments of PC and PD0 showed a fast reduction in the coefficient of reduction of water evaporation from soil, after 6,5 mm of EToac. The lowest value of Kr at the end of the cycle of drying, 0,47, was observed for the treatment PD0. The PD6 has remained longer in the first stage of evaporation, reducing the Kr when EToac exceeded 20,0 mm.
Mundialmente, o setor agrícola é o maior consumidor de água, alcançando cerca de 69% do total de água derivada de rios, lagos e aqüíferos subterrâneos. Em função deste grande consumo de água pela agricultura e pela escassez de água em várias partes do mundo, há uma pressão social e ambiental muito grande, principalmente sobre a agricultura irrigada, a fim de melhorar a eficiência do uso da água. Este estudo teve como objetivo quantificar as perdas de água do solo por evaporação, nos estádios iniciais de desenvolvimento da cultura do milho semeada em sistema de cultivo direto e preparo convencional. O trabalho foi desenvolvido em Área Experimental do Departamento de Engenharia Rural da Universidade Federal de Santa Maria (UFSM), RS. O experimento foi conduzido no período de 28 de outubro de 2006 a 10 de dezembro de 2006 e constituiu-se de quatro tratamentos: (i) semeadura direta do milho em solo desnudo (PD0); (ii) semeadura direta do milho com 3,0 Mg ha-1 de palha na superfície do solo (PD3); (iii) semeadura direta do milho com 6,0 Mg ha-1 de palha na superfície do solo (PD6) e, (iv) preparo convencional do solo, sem cobertura de palha na superfície (PC). As perdas de água do solo foram determinadas em quatro ciclos de secagem do solo durante os primeiros 38 dias após a emergência da cultura, realizando-se o balanço hídrico do solo nas camadas de 0 a 10 cm e de 10 a 30 cm, a partir dos dados de umidade volumétrica do solo determinada com um TDR em intervalos de 15 minutos. Determinou-se também, para o primeiro ciclo de secagem do solo os coeficientes de evaporação (Ke) e de redução da evaporação da água do solo (Kr), conforme a metodologia do Kc Dual de cultivo. Pela curta duração dos ciclos de secagem do solo, o crescimento e o desenvolvimento das plantas não foram influenciados pelo sistema de cultivo do solo nas fases iniciais de desenvolvimento da cultura do milho. Na camada de 0 a 10 cm de profundidade, para o primeiro ciclo de secagem do solo, 3,0 Mg ha-1 de palha na superfície proporcionou uma redução nas perdas de água por evaporação de 24,6% e 19,9% em relação ao PC e PD0, respectivamente. Com 6,0 Mg ha-1 de palha, a redução foi de 50,7% e 47,6%,respectivamente. Nos primeiros 30 cm do perfil do solo, a redução nas perdas de água foi de 18,2% e 23%, respectivamente com 3,0 Mg ha-1 de palha. Aumentando para 6,0 Mg ha-1 a redução foi de 38,3% e 42% respectivamente. Com o crescimento da cultura, o aumento nas perdas de água do solo foi devido ao maior desenvolvimento das plantas com aumento da participação da transpiração no consumo de água pela cultura, pelo sombreamento da superfície pelo maior índice de área foliar das plantas. Os tratamentos com PC e PD0 apresentam Ke mais elevado, chegando a 1,32 e 1,17, respectivamente. Com a presença de palha, o máximo valor de Ke foi reduzido para aproximadamente 50% comparados com os tratamentos sem palha na superfície atingindo valores de 0,70 e 0,44, respectivamente, quando EToac era de 10,0 mm. Os tratamentos de PC e PD0 apresentaram uma rápida redução no coeficiente de redução da evaporação da água do solo, após 6,5 mm de EToac. O menor valor de Kr no final do ciclo de secagem, 0,47, foi observado para o tratamento PD0. O PD6 manteve-se por mais tempo no primeiro estagio da evaporação, reduzindo o Kr quando a EToac superou 20,0 mm.
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Michalczyk, Anna [Verfasser], Kurt Christian [Akademischer Betreuer] Kersebaum, Kurt Christian [Gutachter] Kersebaum, Rolf [Gutachter] Nieder, and Jürgen [Gutachter] Böttcher. "Modelling of nitrogen cycles in intensive winter wheat–summer maize double cropping systems in the North China Plain : site specific optimisation of nitrogen fertilisation with regard to nitrogen losses, water protection, productivity and regionalisation / Anna Michalczyk ; Gutachter: Kurt Christian Kersebaum, Rolf Nieder, Jürgen Böttcher ; Betreuer: Kurt Christian Kersebaum." Potsdam : Universität Potsdam, 2019. http://d-nb.info/1218405619/34.
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Ghebretsadik, Amanuel Habte. "Farm planning for a typical crop-livestock integrated farm : an application of a mixed integer linear programming model." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/49965.
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Assignment (MSc) -- University of Stellenbosch, 2004.ENGLISH ABSTRACT: In an integrated crop-livestock production farm, the profitability and sustainability of farm production is dependent on the crop rotation strategy applied. Crop rotations have historically been applied to maintain long-term profitability and sustainabiliry of farming production by exploiting the jointly beneficial interrelationships existing among different crop types and the animal production activity. Monocrop (specifically wheat) growers in the Swartland area of the Western Cape are struggling to maintain long-term profitability and sustainability of the crop production, challenging them to rethink about the introduction crop rotation in the production planning. By making proper assumptions, this paper develops a mixed integer linear programming model to suggest a decision planning for the farm planning problem faced by an integratedcrop- livestock production farmer. The mathematical model developed includes crop production, dairy production and wool sheep production activities, which permitted the consideration of five crop types within a crop rotation system. By assuming that a farmer uses a cycle of at most three years, the crop rotation model was incorporated in the composite mixed integer linear farm planning model. In order to demonstrate the application of the mathematical farm planning model formulated, a case study is presented. Relevant data from the Koeberg area of the Swartland region of the Western Cape was applied. For each planning period, the model assumed that the farm has the option of selecting from any of 15 cropping strategies. A land which is not allocated to any of the 15 crop rotation strategies due to risky production situation is left as grass land for roughage purposes of the animal production. Results of the mathematical model indicated that farm profit is dependent on the cropping strategy selected. Additionally, animal production level was also dependent on the crop strategy appl ied. Furthermore, study results suggest that the profit generated from the integrated crop-livestock farm production by adopting crop rotation was superior to profit generated 1'1'0111 the farm activities which are based on monocrop wheat strategy. Empirical results also indicated that the complex interrelationship involved in a mixed crop-livestock farm operation play a major role in determining optimal farm plans. This complex interrelationships favour the introduction of crop rotation in the crop production activities of the farm under investigation. Crop production risk is the major risk component of risk the farmer faces in the farm production. In this study, risk is incorporated in the mixed integer programrnmg farm planning model as a deviation from the expected values of an activity of returns. Model solution with risk indicated that crop rotation strategy and animal production level is sensitive to risk levels considered. The Results also showed that the incorporation of risk in the model greatly affects the level of acreage allocation, crop rotation and animal production level of the farm. Finally, to improve the profitability and sustainability of the farm activity, the study results suggest that the introduction of crop rotation which consist cereals, oil crops and leguminous forages is of paramount importance. Furthermore, the inclusion of forage crops such as medics in the integrated crop livestock production is beneficial for sustained profitability from year to year.
AFRIKAANSE OPSOMMING: Wisselbou is baie belangrik om volhoubare winsgewindheid te verseker in 'n geintegreerde lewendehawe I gewasverbouing boerdery in die Swartland gebied van Wes-Kaap. "n Monokultuur van veral koring produksie het ernstige problerne vir produsente veroorsaak. In hierdie studie word 'n gemengde heeltallige liniere prograrnmerings-model gebruik om te help met besluitneming in sulke boerderye.Die wiskundige model beskou die produksie van kontant- en voer-gewasse (5 verskillende soorte) asook suiwel- en wol/vleis-produksie (beeste en skape) .Daar word aanvaar dat die boer "n siklus van hoogstens 3 jaar in die wisselbou rotasie model gebruik .. 'n Gevallestudie word gedoen met behulp van toepaslike data van 'n plaas in die Koeberg gebied. Die model aanvaar dat die produsent 'n keuse het uit 16 wisselbou strategic .Resultate toon dat winsgewindheid afhanklik is van die strategie gekies en dat wisselbou beter resultate lewer as in die geval van "n monokultuur.Dit wys ook dat die wisselwerking tussen diereproduksie en gewasproduksie baie belangrik is in die keuse van 'n optimale strategie. Die risiko in gewasverbouing is die belangrikste risiko factor vir die produsent.In hierdie studie word risiko ook ingesluit in die gemengde heeltallige model, naamlik as 'n afwyking van die verwagte opbrengs-waardes .Die model toon duidelik dat gewasproduksie en lewendehawe-produksie baie sensitief is ten opsigte van die gekose risiko vlak. Die studie toon ook dat 'n wisselbou program wat die produksie van graan (veral koring) .oliesade asook voere insluit belangrik is vir volhoubare winsgewindheid Die insluiting van klawers (bv "medics") is veral belangrik hier.