• Authors:
    • Reisenauer, P. E.
    • Kennedy, A. C.
    • Stubbs, T. L.
    • Burns, J. W.
  • Source: Agronomy Journal
  • Volume: 101
  • Issue: 3
  • Year: 2009
  • Summary: Cropping systems in the dryland farming region of eastern Washington State are dominated by winter and spring wheat ( Triticum aestivum L.) and spring barley ( Hordeum vulgare L.). Excessive levels of residue may be an obstacle in the adoption of conservation farming systems. Decomposition of cereal crop residues is associated with fiber and nutrient content, and growers have observed differences in decomposition among cultivars; however, little information exists on their residue characteristics. Cultivars of spring barley (SB), spring wheat (SW), and winter wheat (WW) grown at four locations over two crop years were analyzed for neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), C, and N contents, and winter wheat decomposition was tested in a laboratory incubation study. Acid detergent lignin was highest in spring barley (9.9%), and least in winter wheat (9.2%) and hard white spring wheat (9.5%). Fiber components and nutrient content varied by location, precipitation zone, and cultivar. Residue in the drier year of the study had lower NDF, ADF, ADL, C, and C/N ratio. Foot rot ( Fusarium spp.) - resistant winter wheat cultivars had higher NDF, ADF, and ADL than susceptible cultivars. Laboratory incubation studies showed decomposition of winter wheat straw in soil was correlated with ADF ( R2>0.66, P=0.002) and total N ( R2>0.67, P=0.04). Fiber and nutrient characteristics of residue from wheat and barley cultivars currently produced in the Pacific Northwest can be used to predict residue decomposition in cropping systems that conserve soil and water, and enhance build-up of organic matter.
  • Authors:
    • Wasaya, A.
    • Asif, M.
    • Tanveer, A.
    • Nadeem, M. A.
    • Tahir, M.
    • Ali, A.
    • Jamil-ur-Rehman
  • Source: Pakistan Journal Of Life and Social Science
  • Volume: 7
  • Issue: 2
  • Year: 2009
  • Summary: In field experiment at Faisalabad, Pakistan conducted during August, 2005, the effect of different irrigation management strategies on growth and yield of soybean was investigated. The experiment comprised of eight irrigation practices of viz; rainfed, one irrigation at vegetative growth stage, one irrigation at flowering, one irrigation at pod formation, two irrigations at vegetative growth stage and at flowering, two irrigations at vegetative growth stage and at pod formation, two irrigations at flowering and at pod formation and three irrigations at vegetative growth stage, at flowering and at pod formation. Number of plants m -2, number of pods per plant, number of seeds per pod and seed yield was significantly higher when crop was irrigated with three irrigations at vegetative growth stage, at flowering and at pod formation.
  • Authors:
    • Jabro, J. D.
    • Sainju, U.
    • Stevens, W. B.
    • Evans, R. G.
  • Source: Journal of Environmental Management
  • Volume: 88
  • Issue: 4
  • Year: 2008
  • Summary: Among greenhouse gases, carbon dioxide (CO 2) is one of the most significant contributors to regional and global warming as well as climatic change. A field study was conducted to (i) determine the effect of soil characteristics resulting from changes in soil management practices on CO 2 flux from the soil surface to the atmosphere in transitional land from perennial forages to annual crops, and (ii) develop empirical relationships that predict CO 2 flux from soil temperature and soil water content. The CO 2 flux, soil temperature ( Ts), volumetric soil water content (theta v) were measured every 1-2 weeks in no-till (NT) and conventional till (CT) malt barley and undisturbed soil grass-alfalfa (UGA) systems in a Lihen sandy loam soil (sandy, mixed, frigid Entic Haplustoll) under irrigated and non-irrigated conditions in western North Dakota. Soil air-filled porosity (epsilon) was calculated from total soil porosity and theta v measurements. Significant differences in CO 2 fluxes between land management practices (irrigation and tillage) were observed on some measurement dates. Higher CO 2 fluxes were detected in CT plots than in NT and UGA treatments immediately after rainfall or irrigation. Soil CO 2 fluxes increased with increasing soil moisture ( R2=0.15, P<0.01) while an exponential relationship was found between CO 2 emission and Ts ( R2=0.59). Using a stepwise regression analysis procedure, a significant multiple regression equation was developed between CO 2 flux and theta v, Ts (CO 2 flux=e -3.477+0.123T s+6.381theta v ; R2=0.68, P≤0.01). Not surprisingly, soil temperature was a driving factor in the equation, which accounted for approximately 59% in variation of CO 2 flux. It was concluded that less intensive tillage, such as no-till or strip tillage, along with careful irrigation management will reduce soil CO 2 evolution from land being converted from perennial forages to annual crops.
  • Authors:
    • Jain, L.
    • Kothari, A.
    • Sharma, S.
    • Balyan, J.
    • Jat, M.
  • Source: Journal of Maharashtra Agricultural Universities
  • Volume: 33
  • Issue: 3
  • Year: 2008
  • Summary: A field experiment was conducted during the kharif season of 2001-2004 at Dryland Farming Research Station, Arjia, Bhilwara, Rajasthan, India, to study the suitability of different cropping system of maize and land treatments for reducing runoff and soil loss. Among the land treatments, flat sowing and ridging after first inter-cultural operation in maize was found more effective in reducing runoff and soil loss thereby increasing the yield of maize. Whereas, among cropping systems, intercropping of maize+black gram (2:2) was found more effective in reducing runoff and soil loss and thereby increasing crop yields as compared to sole maize and black gram.
  • Authors:
    • Jia, H.
    • Chen, Z.
    • Ma, C.
    • Yang, Q.
    • Liu, Z.
    • Li, G.
  • Source: Nongye Jixie Xuebao = Transactions of the Chinese Society for Agricultural Machinery
  • Volume: 39
  • Issue: 11
  • Year: 2008
  • Summary: This paper describes the tillage technologies for the tillage system of soil water storage and preservation in the area of dry farming of northern China, with surface mulching, reduced-till and no-till as the core technologies, based on combined operations, to achieve the goal of soil water storage and preservation and improving soil fertility. It summarizes six innovative technologies involving the combined stalk and stubble management technology, in which the stalk and stubble of corn can be broken and partially buried in soil at one time; the universal technology for rototilling and stubble breaking, in which the two operations, can be done on the same blade rotor and disc; the strip reduced-till (no-till) precision seeding technology, in which less-tillage (or only furrowing) is needed in the seed bed; the ridging and film-side furrow sowing technology, in which the ridge is covered with the film and seeds are sowed in the furrow; the mechanical bionic resistance reduction technology, which uses the soil working tool designed based on bionics; and the no-till planting and blockage prevention technology, in which no-till planting is conducted in the residue free seed bed. It also shows the composition diagram of the farming system.
  • Authors:
    • Wang, Z.
    • Hao, M.
    • Wang, L.
    • Li, S.
    • Li, X.
  • Source: Scientia Agricultura Sinica
  • Volume: 41
  • Issue: 9
  • Year: 2008
  • Summary: Objective: Research on effects of monocropping or rotation of different crops on water and different forms of soil organic nitrogen (N) and mineral N in dryland soils is recognized to be of great significance in determining dryland crop sequences, increasing soil fertility, and optimizing nutrients management. Method: Dryland soil samples were taken from 6 cropping systems: fallowing, continuous wheat monocropping, continuous maize monocropping, continuous alfalfa cropping with no-till, pea-wheat-wheat-millet rotation and maize-wheat-wheat-millet rotation, from a 23-year long-term experimental site on the Loess Plateau, to study the effects of cropping systems on soil water, organic N, light fraction organic N and mineral N. Result: Results obtained showed that continuous long-term fallowing system contained the lowest organic N, light fraction organic N and mineral N. Long-period alfalfa cropping with no-till system could promote water storage in topsoil layers, and accumulation of organic and light fraction organic N in 0-20 cm soil layers, but increased exhaustion of water and mineral N in deep soil layers. Continuous monocropping of wheat or maize could all significantly increase soil organic and light fraction organic N contents, and the organic N were increased more by monocropping of wheat. Organic N contents in soil layers of two rotation systems showed no obvious different to monocropping of wheat. Light fraction organic N contents also were not obvious different between two rotations in 0-20 cm soil layers, but they were all significantly higher than wheat or maize monocropping. The amount of soil mineral N was found to depend on the status of crop growing or N fertilizer application at sampling time. Conclusion: Although long term monocropping of legumes without tillage can enhance organic N accumulation by increase the light fraction organic N in soil, the exhaustion of soil water in deep layers is also increased. Rotations of legumes with cereal crops or the shallow and deep root crop rotations are proved to be feasible measures to optimize soil water utilization, increase organic N accumulation in soil, and synergize soil N supply capacity.
  • Authors:
    • Westfall, D.
    • Davis, J.
    • Reich, R.
    • Moshia, M.
    • Khosla, R.
  • Source: Proceedings of the 9th International Conference on Precision Agriculture
  • Year: 2008
  • Summary: Animal manure is a useful resource that could be recycled beneficially for crop production. When applied to the agricultural land, manure can increase grain yield and improve soil fertility. The objective of this study was to assess the influence of variable rate manure applications on grain yield under continuous maize ( Zea mays L.) fields across low, medium and high Management Zones (MZs) in dryland cropping systems. The study was conducted over two consecutive years in northeastern Colorado on a fine-loamy, mixed, mesic Aridic Haplustalfs soil. Treatments included (i) Variable and Constant yield goal manure treatments ranging from 22 to 67 Mg ha -1 and (ii) uniform application of synthetic N fertilizer based on soil testing. Experimental strips were 4.5 m wide and 540 m long spanned across MZs with treatments nested within MZs. Manure applications exhibited positive relationship with grain yield in site-year I (R 2=0.53) and site-year III (R 2=0.98), which were dryland fields in succeeding years. After two years of the on-going study, VYG and CYG manure treatments produced higher grain yield on low MZs as opposed to high MZs. The increased grain yield on low MZ in SY III was due to the increased level of organic matter, mineralized N and increase precipitation. Uniform application of synthetic N fertilizer has shown no improvement in the second year, producing lesser grain yield as opposed to VYG and CYG manure treatments on low producing MZ. Variable rate applications of manure have the potential to significantly enhance maize grain yield of low producing areas of the field. The study suggests that variable rate application of manure has potential to be used as an alternative to or in conjunction with synthetic N fertilizer for improving soil fertility and maintaining or improving grain yield. The key to precision manure management is to find a balance between agronomically and environmentally sound manure application rates across spatially variable soils. The good thing about manure application in dryland farming is that, there is little environmental pollution concern, more especially in semi-arid environment of northeastern Colorado.
  • Authors:
    • Onduru, D. D.
    • Preez, C. C. C. du
  • Source: International Journal of Sustainable Development & World Ecology
  • Volume: 15
  • Issue: 2
  • Year: 2008
  • Summary: Sustainability is socially constructed, and striving for a sustainable agricultural system requires addressing ecological, social and economic dimensions simultaneously. The objective of this study was to assess the sustainability of dryland farming systems of Eastern Kenya based on farmers' perceptions of their farming environment and the implications for rural livelihoods. Farmers' perceptions were elicited through semi-structured interviews in which questionnaires were administered, on single visits, to 30 selected farm households. The study showed that soil fertility and yields of staple food crops (maize) have declined in the past decade and that current farming systems are not able to produce adequate food and income to the dependent households. Thus, the farming system is showing symptoms of unsustainability. Improving farming system sustainability in this dryland area will ultimately require integration of technical and policy options that take cognisance of farmers' abilities, opportunities and socio-economic circumstances.
  • Authors:
    • Rodriguez-del-Bosque, L.
    • Salinas-Garcia, J.
  • Source: Journal of Entomological Science
  • Volume: 43
  • Issue: 2
  • Year: 2008
  • Summary: The effects of tillage, irrigation (10 cm each at 10- to 14-leaf stage, and silking and milk stages, and no supplemental irrigation) and fertilizer (NPK at 0:0:0 or 140:40:0 kg/ha) treatments on the incidence of lepidopteran insects and fungi infesting maize (cv. Pioneer 3025W) were studied in Tamaulipas, Mexico, during 2005-07. The tillage treatments consisted of mouldboard ploughing (discing stalks after harvesting, followed by mouldboard ploughing, discing and row establishment), subsoil-bedding (shredding stalks after harvesting, followed by subsoiling on row centres and establishment of beds), shred-bedding (shredding stalks after harvesting, followed by bedding on old rows), and no-tillage (shredding stalks after harvesting, and spraying 0.6 kg glyphosate and 0.72 kg 2,4-D/ha twice for weed control). Mouldboard ploughing represented conventional tillage, whereas subsoil-bedding and shred-bedding were reduced tillage systems. The lepidopteran species recorded were Helicoverpa zea (86%) and Spodoptera frugiperda (14%). The incidence of these pests was highest in 2006 (91.5%) and lowest in 2007 (49.3%). The most common fungi were Fusarium spp., the highest incidence of which was registered in 2005 (24.4%). The incidence of Aspergillus flavus and Ustilago maydis [ U. zeae] was less than 4.0% regardless of the year. The incidence of lepidopterans significantly varied between the irrigation levels only (greater pest population under dryland farming). Fusarium spp. and A. flavus occurred more frequently under no-tillage compared with other tillage practices. The incidence of Fusarium spp. was higher in irrigated than in dryland maize.
  • Authors:
    • Ahuja, L. R.
    • Nielsen, D. C.
    • Trout, T. J.
    • Ma, L.
    • Saseendran,S. A.
  • Source: Water Resources Research
  • Volume: 44
  • Issue: 7
  • Year: 2008
  • Summary: Increasing competition for land and water resources due to increasing demands from rapid population growth calls for increasing water use efficiency of irrigated crops. It is important to develop location-specific agronomic practices to maximize water use efficiency (WUE). Adequately calibrated and validated agricultural systems models provide a systems approach and a fast alternative method for developing and evaluating agronomic practices that can utilize technological advances in limited irrigation agriculture. The objectives of this study were to (1) calibrate and validate the CERES-maize model under both dryland and irrigated corn ( Zea mays L.) production in northeastern Colorado and (2) use the model with a long-term weather record to determine (1) optimum allocation of limited irrigation between vegetative and reproductive growth stages and (2) optimum soil water depletion level for initiating limited irrigation. The soil series was a Rago silt loam, and the initial water content on 1 January of each year was equal to field capacity in the upper 300 mm and half of the field capacity below this depth. Optimum production and WUE with minimum nitrogen (N) losses were found when (1) a water allocation ratio of 40:60 or 50:50 (uniform) between vegetative and reproductive stages for irrigations up to 100 mm, and a ratio of 20:80 for irrigations above 100 mm was used; and (2) irrigation was initiated at 20% plant-available water (PAW) (80% depletion). When available water for irrigation is limited to 100 mm, irrigating 50% of the area with 200 mm of water at 20:80 split irrigations between the vegetative and reproductive stages produced greater yield than irrigating 100% of the area with 100 mm water. Concepts developed in the study can potentially be adapted to other locations, climates, and crops. However, precise site-specific recommendations need to be developed for each soil-climate zone using the validated system model.