• Authors:
    • Kumar, S.
    • Bishnoi, U. R.
    • Cebert, E.
  • Source: American-Eurasian Journal of Sustainable Agriculture
  • Volume: 1
  • Issue: 1
  • Year: 2007
  • Summary: In southeastern USA, winter wheat as a double crop has proved to be economically profitable and beneficial for soil management to the farmers. Winter rape ( Brassica napus) also has similar potential but its suitability as a double crop and in rotation with summer crops has not been evaluated. Therefore, performance of winter rape in rotation and as a double crop with soyabean, maize, sorghum, and cotton were evaluated for two years. Results showed that the effect of rotation on plant density during both years was significant. Rotational effects on number of pods per plant were non-significant than rape grown as fallow in 2003 but not in 2004. Rape grown after soyabean produced significantly higher seed yield in 2003 (2739 kg ha -1) and 2004 (3129 kg ha -1) than after other crops except maize (2938 kg ha -1) and fallow (2876 kg ha -1). Planting rape after fallow gave significantly the lowest economic returns during both years. Rape gave significantly higher economic returns when planted after maize ($1237) and cotton ($1169) than soyabean-rape and sorghum-rape and fallow-rape rotations in 2003. Similarly, cotton-rape ($1442) and soyabean-rape ($1393) gave significantly higher economic returns per hectare than maize-rape, sorghum-rape, and fallow-rape cropping systems.
  • Authors:
    • Schondelmaier, J.
    • Foerster, J.
    • Weyen, J.
    • Kiviharju, E.
    • Tenhola-Roininen, T.
    • Tanhuanpaeae, P.
    • Manninen, O.
    • Hagberg, P.
    • Dayteg, C.
    • Tuvesson, S.
    • Lafferty, J.
    • Marn, M.
    • Fleck, A.
  • Source: Euphytica
  • Volume: 158
  • Issue: 3
  • Year: 2007
  • Summary: The breeding companies and laboratories involved in this article cover a wide range of crops grown in the temperate climate zone: small grain cereals, oilseed crops, forage crops, turf, vegetables and potato. Speed and efficiency are becoming increasingly important in variety breeding and doubled haploids (DH) and genetic markers are important biotechnological tools to accelerate materials to market. Collaborative research between universities, research institutions and breeding companies has resulted in the routine use of DH technology and molecular markers in practical breeding of barley, wheat and rapeseed. DH populations have been established not only for barley, wheat and rapeseed, but for rye, oat and triticale, where DH technology is less developed. A driver here is the value of the crop e.g. although wheat is less responsive to DH production the value of the end product makes the effort worthwhile. Simple and rapid DNA extraction methods used in high-throughput marker assisted selection (MAS) systems are essential for routine use of markers. MAS is used both to monitor the presence of genes of interest and also to monitor the genetic background. DH technology in forage, turf and vegetables is still in progress and the practical use of markers in all crops is limited by access to trait linked markers. Collaboration and technology transfer with universities, research institutions and breeding companies is essential for the improvement of both DH protocols in recalcitrant crops and marker technology in all crops.
  • Authors:
    • Schomberg, H. H.
    • Franzluebbers, A. J.
    • Endale, D. M.
  • Source: Soil & Tillage Research
  • Volume: 96
  • Issue: 1/2
  • Year: 2007
  • Summary: The type of conservation-tillage management employed could impact surface-soil properties, which could subsequently affect relationships between soil and water quality, as well as with soil C sequestration and greenhouse gas emissions. We determined soil bulk density, organic C and N fractions, plant-available N, and extractable P on Typic Kanhapludults throughout a 7-year period, in which four long-term (>10 years), no-tillage (NT) water catchments (1.3-2.7 ha each) were divided into two treatments: (1) continuation of NT and (2) paraplowing (PP) in autumn (a form of non-inversion deep ripping) with NT planting. Both summer [cotton ( Gossypium hirsutum L.), maize ( Zea mays L.), sorghum ( Sorghum bicolor L. Moench), soybean ( Glycine max L. Merr.)] and winter [wheat ( Triticum aestivum L.), barley ( Hordeum vulgare L.), rye ( Secale cereale L.), crimson clover ( Trifolium incarnatum L.)] crops were NT planted throughout the study under each management system. Soil bulk density was reduced with PP compared with NT by as much as 0.15 Mg m -3, but the extent of reduction was inversely related to the time lag between PP operation and sampling event. Soil organic C became significantly enriched with time during this study under NT (0.49 Mg C ha -1 year -1), but not under PP, in which poultry litter was applied equivalent to 5.7 Mg ha -1 year -1 to all water catchments. Soil maintained a highly stratified depth distribution of organic C and N fractions and extractable P under both NT and PP. Inability to perform the PP operation in the last year of this study resulted in rapid convergence of soil bulk density between tillage systems, suggesting that PP had
  • Authors:
    • Duarte, G.
    • Diaz-Zorita, M.
    • Barraco, M.
  • Source: Wheat Production in Stressed Environments Developments in Plant Breeding
  • Volume: 12
  • Year: 2007
  • Summary: Wheat ( Triticum aestivum L.) grain yields under no-till production systems have been shown to be reduced in the presence of maize ( Zea mays L.) residues. It has been suggested that sowing a greater density of wheat seeds or removing maize residues from the planting rows contributes to avoid this problem. However, the causal factors and the mechanism that produce reductions in wheat yields are no clearly defined. Our objective was to determine the effects of different volumes of maize or soybean [ Glycine max (L.) Merrill] residues on no-tillage wheat establishment and production under field conditions on a Typic Hapludoll from the Pampas region of Argentina. The study was performed during the 2002, the 2003 and the 2004 growing seasons. Two treatments [residue volume (0, 4, 8 and 16 Mg ha -1) and crop residue (maize and soybean)] were imposed after sowing wheat at low and high plant densities, (301 and 396 seed ha -1, respectively). The previous crop was sunflower ( Helianthus annus L.) and the residues were applied on the soil surface immediately after planting and fertilizing with 125 kg ha -1 of Nitrogen. Independently of the quality of the residues and the sowing density, wheat plants m -2, spikes m -2 and grain yields ha -1 decreased when residue volume increased. In general, lower soil temperatures values and variability were observed when increasing the volume of residues. The presence of large amounts of maize or soybean residues causes the reduction in no-tillage wheat productivity (plant stand and numbers of spikes). However, only maize residues causes significant reductions in grain yields, independently of the seeding rate. The absence of significant differences in soil temperature measurements between residues allows us to think that the effects on surface soil temperature are not the main factor explaining the reduction in wheat grain yields in the presence of maize residues. Increasing the seeding rate can contribute to ameliorate the grain yield reduction in the presence of maize residues but further research is required for explaining the reasons for the behavior of the crop.
  • Authors:
    • Mentreddy, R. S.
    • Cebert, E.
    • Kumar, S.
    • Bishnoi, U. R.
  • Source: World Journal of Agricultural Sciences
  • Volume: 3
  • Issue: 3
  • Year: 2007
  • Summary: In the southeastern USA, winter rape in addition to winter wheat can become another commercial crop with benefits such as breaking of disease and insect cycles caused by continuous wheat cropping. Information on agronomic production practices and comparative profitability of rape and wheat for the southeastern USA is lacking. Therefore, from 1998 to 2005, a series of field experiments were conducted on rape to determine the optimum planting date, seeding, nitrogen and sulfur rates, rotation suitability with summer crops and comparative economic value to winter wheat. Results from three planting dates, three seeding rates and four nitrogen rates experiments showed that rape planted in early October produced significantly higher seed yield (3204 kg/ha) than from mid to late October 10-15 (2362 and 2058 kg/ha) plantings. The seeding rate of 6.0 kg/ha and 180 kg N/ha gave the highest (3779 kg/ha) seed yield. Rape response to sulfur application was significant and highest seed yield (3259 kg/ha) was obtained with 30 kg S/ha along with 228 kg N/ha. As a rotation crop after soyabean and maize, rape gave significantly higher yields of 3129 and 2938 kg/ha, respectively, than when planted after cotton (2521 kg/ha) or grain sorghum (2650 kg/ha). Both winter rape and wheat produced similar yields of 2.6 and 2.9 t/ha, respectively. As grain crop, canola with its higher price fetched $220/ha compared to $109/ha from wheat, however, this profitability is almost equal when income from wheat straw was added to that from grain.
  • Authors:
    • Jamwal, J. S.
  • Source: Indian Journal of Agronomy
  • Volume: 51
  • Issue: 1
  • Year: 2006
  • Summary: A field experiment was conducted during rainy ( kharif) and winter ( rabi) seasons of 1998-99 and 1999-2000 at Dryland Research Substation, Rakh Dhiansar, Bari-Brahmana, Jammu and Kashmir, India, to evaluate the residual effect of integrated nutrient management in maize ( Zea mays cv. GS 2) on succeeding Gobhi sarson ( Brassica napus [ B. campestris var. sarson] cv. GSL 2) and chickpea ( Cicer arietinum cv. PBG 1). Application of recommended dose of NPK (60:40:20 kg/ha)+20 kg ZnSO 4/ha during kharif significantly increased the grain yield of maize as well as the succeeding crops of Gobhi sarson and chickpea. Application of farmyard manure (FYM) significantly increased the available N, P and K status of the soil after maize harvest. Available P status of the soil after the harvest of Gobhi sarson and chickpea also increased significantly due to the residual effect of FYM and fertility levels.
  • Authors:
    • Bali, S. V.
    • Singh, B.
    • Lehria, S. K.
  • Source: Short Rotation Forestry for Industrial and Rural Development
  • Year: 2006
  • Summary: A field experiment was conducted at Rakh Dhiansar during Kharif 1995 and 1996 and Rabi 1995-96 and 1996-97 under dryland conditions of Jammu (J&K). The results based on growth, yield attributes and yield revealed that application of 15 t ha -1 of subabul leaves as basal+25% N recorded maize (var. Local) yield of 45.22 q ha -1, which was significantly higher than the recommended dose of fertilizers and it was at par with 15 t ha -1 of subabul leaves as basal only, yielding 45.06 q ha -1. The residual effect of green leaf manuring on wheat (var. PBW-175) revealed that growth, reproductive and yield attributing characters were also influenced positively. By using this material, 50-75% N can be saved by the small and marginal farmers of the dryland region.
  • Authors:
    • Paulitz, T. C.
  • Source: European Journal of Plant Pathology
  • Volume: 115
  • Issue: 3
  • Year: 2006
  • Summary: Direct-seeding or no-till is defined as planting directly into residue of the previous crop without tillage that mixes or stirs soil prior to planting. No-till reduces soil erosion, improves soil structure and organic matter, and reduces fuel inputs. No-till is widely used in cereal production in Australia, Canada, Argentina, and Brazil, but has not been widely adopted in Europe and the Pacific Northwest of the U.S. One of the limitations is that root diseases may increase with a reduction in tillage. This paper discusses the importance and management of take-all, Fusarium dryland foot rot, Rhizoctonia bare patch and root rot, and Pythium root rot in dryland cereal production systems, and how they are influenced by changes in tillage practices. To address this challenge, specifically with Rhizoctonia and Pythium, our research group has (1) developed classical and molecular techniques to detect and quantify Rhizoctonia and Pythium spp. from the soil to assess disease risk; (2) studied the disease dynamics of root disease during the transition from conventional to no-till; (3) developed greenhouse methods to screen germplasm for tolerance or resistance to Pythium and Rhizoctonia, and (4) using GPS and geostatistics, has examined the spatial distribution of R. solani and R. oryzae at a field scale up to 36 ha, across a number of crop rotations and years. By a combination of ecological, epidemiological, field, and laboratory studies, we hope to provide growers with a set of disease management tools to permit the economical and sustainable production of dryland cereals without degradation of the soil resource.
  • Authors:
    • Pitts, T.
    • Atwood, J. D.
    • Williams, J. R.
    • Potter, S. R.
    • Wang, X.
  • Source: Transactions of the ASABE
  • Volume: 49
  • Issue: 3
  • Year: 2006
  • Summary: Sensitivity analysis for mathematical simulation models is helpful in identifying influential parameters for model outputs. Representative sets of APEX (Agricultural Policy/Environmental eXtender) model data from across the U.S. were used for sensitivity analysis to identify influential parameters for APEX outputs of crop grain yields, runoff/water yield, water and wind erosion, nutrient loss, and soil carbon change for a national assessment project: the Conservation Effects Assessment Project (CEAP). The analysis was based on global sensitivity analysis techniques. A test case, randomly selected from the representative sets of APEX model data, was first analyzed using both the variance-based sensitivity analysis technique and the enhanced Morris method. The analysis confirmed the reliability of the enhanced Morris measure in screening subsets of influential and non-influential parameters. Therefore, the enhanced Morris method was used for the national assessment, where the cost of applying variance-based techniques would be excessive. Although sensitivities are dynamic in both temporal and spatial dimensions, the very influential parameters (ranking 1st and 2nd) appear very influential in most cases. Statistical analyses identified that the NRCS curve number index coefficient is very influential for runoff and water-related output variables, such as soil loss by water, N and P losses in runoff. The Hargreaves PET equation exponent, moisture fraction required for seed germination, RUSLE C factor coefficient, and the potential heat units are influential for more than two APEX outputs studied.
  • Authors:
    • Macdonald, B. C. T.
    • Bryant, G.
    • White, I.
    • Moody, P.
    • Stainlay, W.
    • Dalal, R. C.
    • Denmead, O. T.
  • Source: Proceedings of the Australian Society of Sugar Cane Technologists
  • Volume: 28
  • Year: 2006