• 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:
    • Vigil, M. F.
    • Nielsen, D. C.
    • Mikha, M.
    • Benjamin, J. G.
    • Calderon, F.
    • Henry, W. B.
  • Source: Soil Science Society of America Journal
  • Volume: 71
  • Issue: 4
  • Year: 2007
  • Summary: No-till cropping systems in the semiarid West have the potential to improve soil physical properties by increasing cropping intensity and crop diversity. An investigation at Akron, Colorado, USA, compared soil conditions in winter wheat ( Triticum aestivum)-summer fallow (WF) plots with soil conditions in wheat-maize ( Zea mays)-fallow (WCF), wheat-maize-sunflower ( Helianthus annuus)-fallow (WCSF), wheat-maize-millet ( Panicum miliaceum) (WCM), and a perennial grass/legume mix. The study began in 1990. Bulk density, pore size distribution, and saturated hydraulic conductivity were measured 7, 11, and 15 years after inception. Bulk density in the grass plots decreased from 1.39 to 1.25 Mg m -3 in 15 years. Bulk density in the annually cropped plots decreased from 1.38 to 1.30 Mg m -3 during the same time period. The pore size distribution became more uniform among the cropped treatments 15 years after the start of the experiment. Saturated hydraulic conductivity increased in the grass plots from 27 to 98 mm h -1 in 15 years. Saturated hydraulic conductivity in the annually cropped plots increased from approximately 14 to approximately 35 mm h -1 during the same period. The results show that improving soil physical properties by cropping system alone may take many years. Perennial vegetation may be more effective than annually cropped systems at improving soil physical conditions because of less surface compaction from planting operations and the apparent ability of perennial root systems to create a more stable, continuous pore network.
  • 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:
    • Kahlown, M. A.
    • Azam, M.
    • Kemper, W. D.
  • Source: Journal of Soil and Water Conservation
  • Volume: 61
  • Issue: 1
  • Year: 2006
  • Summary: Conventional management practices for the rice-wheat rotation in Pakistan's Punjab have failed to improve crop yield, increase water and fertilizer use efficiencies, and decrease production costs enough to meet an ever-increasing food demand. New technologies such as no-till, laser leveling, and bed and furrow irrigation are being rapidly adopted by the farming community, but without adequate scientific information. Therefore, those practices were evaluated on 71 farms within four representative sites. Land preparation/sowing costs, water savings, use of fertilizers, soil salinity, and crop yield were evaluated. Land preparation and sowing cost on no-till fields was significantly less than on tilled fields. Highest yields were obtained on laser-leveled fields, followed by no-till, bed and furrow fields. Water and nitrogen use efficiencies were much higher on fields with bed and furrow irrigation as compared to the conventional fields. Although the new technologies were economically feasible, we conclude that no-till was the best option for the farmers.
  • 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:
    • Merrill, S. D.
    • Krupinsky, J. M.
    • Tanaka, D. L.
    • Anderson, R. L.
  • Source: Journal of Soil and Water Conservation
  • Volume: 61
  • Issue: 1
  • Year: 2006
  • Summary: Soil coverage by residue protects soil and land resources from erosion, conserves soil water, and maintains soil quality. No-till and chemical weed control are management practices that increase soil coverage by residue. On the other hand, crop diversification in dryland agriculture in the northern Great Plains promotes the use of crops that produce significantly less soil coverage by residue than small cereal grains. Within a 10 x 10 crop sequence project under no-till in south-central North Dakota [409 mm (16.1 in) mean annual precipitation], all two-year crop sequence combinations of ten crops (barley, canola, crambe, dry bean, dry pea, flax, safflower, soybean, spring wheat, and sunflower) were evaluated at two adjacent sites. Soil coverage by residue was measured by transect and photographic techniques following spring wheat seeding. Soil coverage ranged from 98 to 89 percent following crop sequences that included spring wheat and barley. Soil coverage values were intermediate for spring wheat-alternative crop sequences, 97 to 62 percent. Crop sequences not including spring wheat with alternative crops for two years had values ranging from 86 to 35 percent. Soil coverage values after two consecutive years of sunflower or dry pea (two years of data) and two years of dry bean or safflower (single year of data) were in a lower range, 48 to 35 percent. Soil erosion hazards were evaluated with equations based on residue effects alone that were taken from the Revised Universal Soil Loss Equation (RUSLE) water erosion and Revised Wind Erosion Equation (RWEQ) wind erosion models: calculated soil loss ratio values (SLR = 1 with no residue protection) for 35 percent coverage following a sunflower-sunflower sequence were 0.29 for water erosion and 0.21 for wind erosion. Even with use of no-till, especially on more fragile soils, producers should consider planting a higher residue-producing crop (e.g., wheat, flax) the year before seeding lower residue-producing crops in order to assure adequate protection of soil and land resources.
  • Authors:
    • Miller, P. R.
    • Engel, R. E.
    • Holmes, J. A.
  • Source: Agronomy Journal
  • Volume: 98
  • Issue: 6
  • Year: 2006
  • Summary: Annual legumes permit intensified cropping in no-till systems in the drought-prone northern Great Plains. Our objectives were to compare cropping sequence effects of pea ( Pisum sativum L.) with fallow, mustard ( Sinapis alba L.), and wheat ( Triticum aestivum L.), and to measure the effects of pea harvest timing and shoot biomass presence on soil water use and N contribution, and yield and grain quality of subsequent wheat. Pea, mustard, wheat, and fallow preceded spring wheat at three sites in Montana. In the first year, two harvest timings (anthesis and maturity) were included and managed for presence or absence of crop shoot biomass. In the second year, a wheat test crop was grown at four N fertilizer rates. Regardless of management, pea used equal or less soil water, contributed equal or greater soil N, and had equal or greater positive impact on subsequent wheat growth than mustard or wheat. Compared with maturity, midseason harvest timing of pea increased soil N (30-39 kg NO 3-N ha -1) and soil water (19-39 mm) available in the spring to the subsequent wheat test crop at two of three sites. Under severe drought, midseason harvest of pea increased wheat yield 50% and critically increased grain density compared with the mature pea harvest. At the N-limited site, midseason harvest of pea increased wheat yield 14% and grain protein 9% compared with mature pea harvest. Pea shoot biomass presence did not affect soil water or N, or growth of a subsequent wheat crop.
  • Authors:
    • Nielsen, D. C.
    • Vigil, M. F.
    • Benjamin, J. G.
  • Source: Agronomy Journal
  • Volume: 98
  • Issue: 4
  • Year: 2006
  • Summary: Forages, with greater water use efficiency (WUE) than grain and seed crops, could be used to diversify reduced and no-till dryland cropping systems from the traditional wheat ( Triticum aestivum L.)-fallow system in the semiarid central Great Plains. However, farmers need a simple tool to evaluate forage productivity under widely varying precipitation conditions. The objectives of this study were to (i) quantify the relationship between crop water use and dry matter (DM) yield for corn ( Zea mays L.), foxtail millet ( Setaria italica L. Beauv.), and winter triticale ( X Triticosecale Wittmack); and (ii) determine the range and distribution of expected DM yields for these three crops in the central Great Plains based on historical precipitation records. The three crops were grown in a dryland no-till corn-millet-triticale sequence from 1998 through 2004 at Akron, CO. Dry matter production was linearly correlated with water use for all three crops, with regression slopes ranging from 24.2 (corn) to 33.0 kg ha -1 mm -1 (millet). Water use efficiency varied widely from year to year (0-32.2 kg ha -1 mm -1) for the three crops, as influenced by growing season precipitation and time of year in which the crops were grown. Millet and triticale produced similar amounts of DM for a given water use, while corn produced less. Precipitation use efficiency for the millet-triticale-corn forage system was 8.7 kg ha -1 mm -1, suggesting this as an efficient forage system for the region.
  • Authors:
    • Pala, M.
  • Source: Options Mediterraneennes. Serie A, Seminaires Mediterraneens
  • Issue: 69
  • Year: 2006
  • Summary: The past several decades have witnessed a change from traditional to more intensive agriculture in dryland farming systems of West Asia and North Africa and also in the transitional period of Central Asia and Caucasus (CAC). These two areas can be combined and called the Central and West Asia and North Africa (CWANA) region, which covers diverse agroecological conditions from mild lowlands (Syria) to cold continental (CAC) and cold highlands (Turkey). This region is a major area of the world where drought invariably limits crop production in approximately 1.7 million ha arable land. Agriculture is primarily based on rainfed cropping during the relatively cooler late autumn to early spring as rainfall ranged generally between 200 to 600 mm per year. Dryland crops are mainly wheat, food legumes such as lentil, chickpea, faba beans, and forage legumes such as vetch, medics and lathyrus. Increasing human and livestock population has led desertification and soil degradation in the region. This has led also ICARDA to an assessment of tillage systems for efficiency, enhanced productivity and sustainability of the various farming system changes through a series of long-term trials in the mid 1980s at ICARDA headquarter as well as in the National Agricultural Research Services in close collaboration. Results at ICARDA and the region support a preference for the conservation tillage system (minimum tillage) over deep tillage systems on the grounds of both energy-use efficiency and increased net revenue as direct benefits to livelihood of the rural population. However, whenever available and tested and adopted by farmers with their participatory evaluation as in Central Asia, no-till direct drilling would increase soil organic matter from approximately 0.9% to 1.3% at 0-10 cm top soil and sustain the systems productivity in the long-run on the basis of the initial research results throughout the CWANA 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.