• 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:
    • Owoeye, L.
    • Moriri, S.
    • Mariga, I.
  • Source: Proceedings of the 9th International Conference on Precision Agriculture, Denver, Colorado, USA
  • Year: 2008
  • Summary: Field experiments were carried out during 2005/2006 growing season at three localities to assess effects of planting density and planting patterns on crop growth, maize stover nutrient concentration and residual soil nutrient content in maize/cowpea sole and intercropped systems. The trial consisted of four maize planting densities and six planting patterns. Higher plant density of 30 000 and 40 000 maize plants ha -1 delayed flowering and maturity of both component crops in sole and intercropped systems. Maize dry matter production increased with increasing plant density up to 30 0000 plants ha -1 and reduced at higher density of 40 000 plants ha -1, whereas cowpea dry matter production decreased with increasing plant density in intercropping but this was the opposite in sole cropping. The 1rowM:2rowsC pattern and plant density of 30 000 plants ha -1 with 92 000 plants ha -1 of cowpeas was superior in maize dry matter production at all trial sites, whereas sole cowpea at 40 000 plants ha -1 gave the highest dry matter yield than the intercrop. The 2rowsM:4rowsC arrangement had the tallest cowpea plants than all other planting patterns, while the 1rowM:1rowC arrangement had the shortest at all locations throughout the sampling dates.
  • Authors:
    • Pringle, H.
    • Ebelhar, M.
    • Martin, S.
  • Source: Journal of Cotton Science
  • Volume: 12
  • Issue: 4
  • Year: 2008
  • Summary: Increasing available soil water for a crop can be accomplished with both deep tillage and irrigation. Both have the potential to replace or complement the other due to their common function. The addition of a crop rotation may also enhance or diminish the response from irrigation and/or deep tillage. The major objective of this study was to determine long-term effects of different levels of furrow irrigation and in-row subsoil tillage on lint yield and economic returns for cotton grown on alluvial silty clay loam soils in a cotton/corn cropping sequence. A secondary objective was to determine the ability and efficiency of deep tillage and irrigation to replace and/or complement each other in the cropping system. Field experiments were conducted at Tribbett, MS on silty clay loam soils from 1999 through 2004. In-row subsoil tillage was performed with a low-till parabolic subsoiler. A roll-out pipe system was used to furrow water the irrigated plots. Production costs were calculated and include direct costs plus total specified costs excluding land rent, general farm overhead, and returns to management. Growing non-irrigated cotton without deep tillage in this cotton/corn sequence on these silty clay loam soils that were prone to backwater flooding gave the highest average net returns. It appears producers should neither subsoil, nor furrow irrigate and the two should never be combined, based on this study. These results emphasize the need for drainage and support the need for further research on these type soils in the absence of drainage problems.
  • 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.
  • Authors:
    • Rani, K. U.
    • Madhavi, M.
    • Ramesh, G.
    • Sankar, G. M.
    • Ravindrachary, G.
    • Adake, R. V.
    • Grace, J. K.
    • Korwar, G. R.
    • Mishra, P. K.
    • Srinivas, K.
    • Mandal, U. K.
    • Jain, P. M.
    • Jat, M. L.
    • Kothari, A. K.
    • Laddha, K. C.
    • Sharma, K. L.
  • Source: Indian Journal of Dryland Agricultural Research and Development
  • Volume: 23
  • Issue: 1
  • Year: 2008
  • Summary: Rainfed soils of Arjia region, Gujarat, India, which are under maize based production system, are damaged due to several soil related productivity constraints such as loss of topsoil causing severe soil erosion. The yield levels of majority of the crops grown in these soils are low. Soil quality deterioration has been the major bottleneck in realizing the higher levels of crop yields in this rainfed region. Hence, there was a need to identify and adopt appropriate soil and plant management practices that reduce soil degradation or maintain and improve soil quality at a desirable level. In view of the above, a long-term experiment was adopted for assessing soil quality as influenced by different soil-nutrient and other management practices followed at All India Coordinated Research Project for Dryland Agriculture centre of Arjia. Soil samples were analysed for 19 physical, chemical and biological soil quality parameters and soil quality indices were worked out using deviation method. From the viewpoint of soil quality improvement or soil aggradation, combination of conventional tillage + 2 weedicides + hoeing + 100% organic N ranked as superior among most treatment with the relative soil quality index value as high as 0.95 under maize-blackgram system. Further, cropping systems adjoining to the experimental station were also evaluated for soil quality. In the farmers' fields, the order of the systems in aggrading soil quality was as: maize-blackgram (1.00) > groundnut-sesame (0.75), > groundnut-taramira (0.72). The full paper deals in length about the extent and magnitude of changes in soil quality parameters and relative soil quality indices.
  • Authors:
    • Sharma, S. K.
    • Kothari, A. K.
    • Sharma, R. K.
    • Jain, P. M.
  • Source: Journal of Agrometeorology
  • Volume: 10
  • Issue: Special issue 1
  • Year: 2008
  • Summary: This paper draws on experiences with several participatory research activities carried out during 2005 and 2006 in the context of an Operational Research Project of All India Coordinated Research Project for Dryland areas carried out at the village Pathliyas situated in Mangarope watershed, Rajasthan, India. Data on the climatic constraints, drought and use of agro-advisory services from 45 households were collected to identify key track indicators for measuring community progress. The yield gap analysis of different crops in the watershed region presented indicated that technology gap existing between the potential and demonstrable yields was not substantial. Thus, it was possible to replicate the results obtained in research experiments in on-farm situation. The technology index varied from 20 to 47% which gave evidence that there was scope for further improvement in the productivity. The adoption of contingency plan for mitigating aberrant weather situation revealed that the adoption of different dryland technologies varied from 10 to 88%. During 2006-07, there was 30 days early onset of monsoon so sowing of maize and groundnut was forbidden based on land topography. Village survey result indicated that out of total cropped area (100 ha), maize and groundnut crops were sown on 35 and 10% of the area until the second week of June. Only 5% of the area was sown with the recommended agro-advisory services. However, the success rate of such farmers was not more than 10%. Thus, for higher sustainability, equality and stability of production, the agro-advisory services must be a vital component of action research and more emphasis should be given to capitalize on them.
  • Authors:
    • Dhuyvetter, K. C.
    • Staggenborg, S. A.
    • Gordon, W. B.
  • Source: Agronomy Journal
  • Volume: 100
  • Issue: 6
  • Year: 2008
  • Summary: Grain sorghum [ Sorghum bicolor (L.) Moench] is often grown where water stress is expected. But, improved drought tolerance in corn ( Zea mays L.) hybrids has resulted in increased dryland corn production in preference to grain sorghum. However, grain sorghum may still have a yield advantage over corn in drought prone environments. This study was conducted to determine if grain sorghum has either a yield or economic advantage over corn when drought or temperature stress occurs. Yield and weather data from crop performance testing programs in Kansas and Nebraska (1992-2005) were analyzed. Grain sorghum produced higher yields than corn in environments where corn yields were <6.4 Mg ha -1. When net returns ($ ha -1) were considered for grain sorghum prices that were set at 70, 87, 100, and 117% of corn prices, grain sorghum net returns were higher than corn net returns when corn yields were ≤4.4, 6.6, 8.8, and 13.6 Mg ha -1, respectively. Both corn and grain sorghum yields were positively correlated to June through August precipitation and negatively correlated to June through August maximum temperatures. The yield difference (grain sorghum minus corn) increased as July and August maximum temperatures increased. Monthly minimum temperatures affected corn yield less than grain sorghum yield. Producers in this region likely can minimize production risks by considering this historical yield information. At locations in this region where corn yields are consistently <6.4 Mg ha -1, producers should consider producing grain sorghum.
  • Authors:
    • Parvender, S.
    • Sukhvinder, S.
  • Source: Indian Journal of Dryland Agricultural Research and Development
  • Volume: 23
  • Issue: 2
  • Year: 2008
  • Summary: To study the impact of different cultural and chemical weed management practices alone and in combination on maize under rainfed conditions, a field experiment was conducted during 1996 and 1997 at farmer's fields in Hoshiarpur, Punjab, India, as a part of All India Coordinated Operational Research Project for Dryland Agriculture. There were 8 weed control treatments, i.e. weedy control, one hoeing at 15 days after sowing (DAS) alone and in combination with cut grass as mulch, 2 hoeings at 15 and 30 DAS, pre-emergence application of atrazine at 0.63 kg/ha alone and in combination with one hoeing at 35 DAS, post-emergence application of atrazine at 0.63 kg/ha in combination with one hoeing at 35 DAS, pre-emergence application of alachlor at 2.50 kg/ha in combination with one hoeing at 35 DAS. The important weed species in the field were Echinochloa colonum [ E. colona], Cyperus rotundus, Eleusine aegyptiacum [ Dactyloctenium aegyptium], Digera arvensis, Commelina benghalensis and Sorghum halepense. The pre-emergence application of atrazine in combination with one hoeing at 35 DAS resulted in the lowest weed density, total weed dry weight and highest mean grain yield (31.34 q ha -1) and was statistically at par with pre-emergence application of alachlor in combination with one hoeing at 35 DAS (29.86 q ha -1) and post-emergence application of atrazine in combination with one hoeing at 35 DAS (28.86 q ha -1). Application of atrazine (pre or post emergence) in combination with one hoeing at 35 DAS resulted in 7.48% higher mean grain yield over application of atrazine alone, while the same recorded 20.46% yield increase over 2 hoeings at 15 and 30 DAS, indicating the beneficial effect of chemical weed control compared to hoeing in the initial stages of crop growth.