• Authors:
    • Haqqani, A. M.
    • Munir, M.
    • Mann, R. A.
  • Source: Pakistan Journal of Agricultural Research
  • Volume: 18
  • Issue: 1
  • Year: 2002
  • Summary: Rice-wheat cropping system is the most important one in Pakistan. The system provides food and livelihood for more than 15 million people in the country. The productivity of the system is much lower than the potential yields of both rice and wheat crops. With the traditional methods, rice-wheat system is not a profitable one to many farmers. Hence, Cost of cultivation must be reduced and at the same time, efficiency of resources like irrigation water, fuel, and fertilizers must be improved to make the crop production system more viable and ecofriendly. Resource conserving technology (RCT) must figure highly in this equation, since they play a major role in achieving the above goals. The RCT include laser land leveling, zero-tillage, bed furrow irrigation method and crop residue management. These technologies were evaluated in irrigated areas of Punjab where rice follows wheat. The results showed that paddy yield was not affected by the new methods. Direct seeding of rice crop saved irrigation water by 13% over the conventionally planted crop. Weeds were the major problem indirect seeded crop, which could be eliminated through cultural, mechanical and chemical means. Wheat crop on beds produced the highest yield but cost of production was minimum in the zero-till wheat crop. Planting of wheat on raised beds in making headway in lowlying and poorly drained areas. Thus, resource conserving tillage technology provides a tool for making progress towards improving and sustaining wheat production system, helping with food security and poverty alleviation in Pakistan in the next few decades.
  • Authors:
    • Chanasyk, D. S.
    • Mathison, M. N.
    • Naeth, M. A.
  • Source: Canadian Journal of Soil Science
  • Volume: 82
  • Issue: 2
  • Year: 2002
  • Summary: The longevity of deep ripping effects on Solonetzic soils was investigated at 11 field sites in east-central Alberta after a period of 15 to 20 yr. Select soil properties and crop yield of deep-ripped and non-ripped control plots were analyzed. Dryland yield data of wheat, barley, oats and canola were assessed for 10 of the 11 sites over a 16-yr time period. Select soil properties were analyzed once in 1998 with penetration resistance (PR) evaluated again in 1999. A significant difference in penetration resistance was found between the deep ripped versus control treatments ( P≤0.05). There were no significant treatment differences for soil texture, bulk density (Db), pH, electrical conductivity (EC) or sodium adsorption ratio (SAR). A significant yield difference between the deep ripping and control treatments (for all crop species) was found for 6 of 10 sites ( P≤0.10), with all sites having an increase in mean yield for the majority of years evaluated. Generally, sites in the drier ecoregions had smaller yield increases than those in the wetter ones. Hence some beneficial effects from deep ripping remain for a long time period.
  • Authors:
    • Aroca, J. A.
    • Guerrero-Campo, J.
    • Bienes, R.
    • Nicolau, J. M.
    • Gomez, B.
    • Espigares, T.
  • Source: Man and soil at the Third Millennium. Proceedings International Congress of the European Society for Soil Conservation, Valencia, Spain, 28 March-1 April, 2000. Volume 2 2002
  • Year: 2002
  • Summary: The desertion of large agricultural lands in Mediterranean areas has important consequences on soil erosion. The aim of this study was to quantify runoff and water soil erosion evolution during the period 1994-97. Runoff and erosion were measured in erosion plots (20* 4 m). Four different treatments were applied, namely bare soil maintained with herbicide, no-tilled barley crop, spontaneous vegetation and leguminous sowing before desertion. These trials were carried out in four areas with different types of soils. The areas are located in the centre of Spain, under a Mediterranean-continental climate. In bare soils, annual runoff coefficient was higher than 10%, increasing through the time because of the soil compaction. These plots showed high soil erosion rates, between 1.3 and 28 t ha/year. Spontaneous vegetation plots produced the lowest erosion rates (from 0.0002 to 0.15 t ha/year). Annual runoff coefficient in no-tilled barley plots increased lightly through the four years, because the minimum ploughing favoured a light soil compaction. Soil erosion rate was low, ~0.3 t ha/year, showing the efficiency of this crop on erosion control. Runoff coefficient in abandoned plots (with spontaneous vegetation) and plots with leguminous sowing before desertion, decreased through the time. The lowest erosion rates were recorded when plant cover was higher than 50%, that is, from 6 months to 2.5 years after crops desertion. It is shown that in these environments soil erosion is not a continuous process, because the main water erosion measured during the four years period were produced only in two or three big storms.
  • Authors:
    • Nielsen, G.
    • Mortensen, D.
    • McGinn, S.
    • Coen, G.
    • Caprio, J.
    • Waltman, S.
    • Padbury, G.
    • Sinclair, R.
  • Source: Agronomy Journal
  • Volume: 94
  • Issue: 2
  • Year: 2002
  • Summary: The northern Great Plains have long been dominated by conventional tillage systems and cereal-based rotations including summer fallow. Over the last decade, however, the use of conservation tillage systems has markedly increased and, through improved moisture storage, has provided an opportunity for more diversified extended rotations including oilseed, pulse, and forage crops throughout the region. Considerable research is being carried out to assess the adaptability of these new crops and to develop appropriate management strategies. Typically, this type of agronomic research is carried out at plot-sized research sites, with the findings then being extrapolated to surrounding regions where growing conditions are thought to be reasonably similar. Because the environment itself largely dictates the success of a particular cropping system, extrapolation requires knowledge of the environmental conditions of the region and, in particular, the interaction of environmental components of soil and climate in relation to specific crop requirements. This paper describes 14 agroecoregions in the northern Great Plains and provides an initial framework for extrapolating agronomic information at broad regional scales. Because climate is the dominant crop production factor in the region, most of the agroecosystems represent broad climatic zones. Each agroecoregion is described in terms of its soil and landscape characteristics, with a particular focus being given to likely key environmental parameters related to the production of the new oilseed, pulse, and forage crops being introduced in the region.
  • Authors:
    • Dillon, C. R.
    • Oliver, L. R.
    • McNew, R. W.
    • Keisling, T. C.
    • Popp, M. P.
    • Wallace, D. M.
  • Source: Agronomy Journal
  • Volume: 94
  • Issue: 1
  • Year: 2002
  • Summary: Soyabean ( Glycine max) yields from non-irrigated fields in the mid-southern USA have consistently lagged behind those from irrigated fields. Nonetheless, non-irrigated fields still attract a larger share of soyabean acreage in this region. This is likely due to various irrigation constraints, which include land leasing arrangements, water shortage, lack of management time and low levels of operating capital. The objective of this study was to identify production system components consisting of tillage, cultivar selection and planting date strategies for a soil series that are most suitable for enhancing economic returns to dryland soyabean. Data from field experiments in three locations in Arkansas, USA during 1995 and 1996 were used for the study. Leading production systems were identified on the basis of their net returns. Results of the study showed that the performance of the production systems in terms of crop yields and net returns is influenced by the location and production year. While the evidence on pure planting date effects was confounded with physical field location, cultivar yields from early soyabean plantings in April and May were generally higher than those from later plantings. Furthermore, conventional and fallow production systems had higher net returns than no-till systems, largely due to higher herbicide costs associated with no-till systems. Sensitivity analysis showed that planting date and seedbed preparations are robust to changes in herbicide, fuel and soyabean prices. Further, careful attention to cultivar selection is deemed appropriate because cost differences of cultivar seeds are minor relative to net return differences that are yield driven.
  • Authors:
    • Delaney, D. P.
    • Reeves, D. W.
  • Source: E. van Santen (ed.) 2002. Making Conservation Tillage Conventional: Building a Future on 25 Years of Research. Proc. of 25th Annual Southern Conserva­tion Tillage Conference for Sustainable Agriculture. Auburn, AL, 24-26 June 2002. Special Report no. 1.
  • Year: 2002
  • Summary: Intensive cropping and conservation tillage can increase soil organic C (SOC) and improve soil quality, however, economic reality often dictates cotton ( Gossypium hirsutum) monoculture. We conducted a study on a Compass loamy sand (coarse-loamy, siliceous, subactive, thermic Plinthic Paleudults) from 1998-2001 to compare an intensive conservation cropping system to standard cotton production systems used in the southeastern USA (Alabama). The system uses sunn hemp ( Crotalaria juncea) and ultra-narrow row (UNR; 8-inch drill) cotton in a rotation with wheat ( Triticum aestivum) and maize ( Zea mays). The standard systems used continuous cotton (both standard 40-inch rows and ultra-narrow row) and a maize-cotton rotation with standard row widths. A cover crop mixture of black oat ( Avena strigosa [ A. nuda])/rye ( Secale cereale) was used in all systems preceding cotton and a white lupin ( Lupinus albus)/crimson clover ( Trifolium incarnatum) mix was used before maize in the maize-cotton and intensive system. All systems were tested under conservation and conventional tillage in a split plot design of four replications; main plots were cropping systems and subplots were tillage. We used extension budgets to calculate net returns over variable costs and determined C balance of all residues returned to the soil. At the end of the experiment, soil C was determined by dry combustion (0-0.4, 0.4-2, 2-4, 4-8, and 8-12 in depths). Cropping system had a more consistent effect on cotton yield than tillage system. Four-year average lint yields were 872, 814, 711 and 663 lbs acre -1 for continuous UNR, intensive, maize-cotton, and continuous 40-in cotton systems, respectively. The UNR systems with conservation tillage had the highest net returns ($105 acre -1 year -1 (continuous) and $97 acre -1 year -1 (intensive)) while the conventional tillage continuous 40-in system had the lowest returns ($36 acre -1 year -1). Conservation tillage increased SOC concentration in the top 2 inches of soil 46% compared to conventional tillage. Cropping system affected SOC levels to the 4-in depth and the maize-cotton rotation resulted in the lowest SOC levels of all systems. Results suggest that small grain cover crops and wheat for grain in the intensive system were the dominate factor in SOC changes. For these drought-sensitive soils, UNR cotton production systems with conservation tillage and small grain cover or cash crops have the potential to rapidly increase soil organic matter; improving soil productivity and enhancing economic sustainability of cotton production in the southeastern USA.
  • Authors:
    • Chambers, B. J.
    • Silgram, M.
  • Source: Journal of Agricultural Science
  • Volume: 139
  • Year: 2002
  • Summary: The effects of straw incorporation (early and late cultivation) and straw burning were contrasted in a split-plot study examining the impact of long-term straw residue management, and six fertilizer nitrogen (N) rates on soil mineral nitrogen, crop fertilizer N requirements and nitrate leaching losses. The experiments ran from 1984 to 1997 on light-textured soils at ADAS Gleadthorpe (Nottinghamshire, UK) and Morley Research Centre (Norfolk, UK). Soil incorporation of the straw residues returned an estimated 633 kg N/ha at Gleadthorpe and 429 kg N/ha at Morley on the treatment receiving 150 kg/ha per year fertilizer N since 1984. Straw disposal method had no consistent effect on grain and straw yields, crop N uptake, or optimal fertilizer N rates. In every year there was a positive response (Pearly incorporate >late plough. The incorporation of straw residues induced temporary N immobilization compared with the treatment where straw was burnt, while the earlier timing of tillage on the incorporate treatment resulted in slightly more mineral N compared with the later ploughed treatment. Fertilizer N rate increased (P < 0.001) soil mineral nitrogen at both sites. At Morley, there was more organic carbon in the plough layer where straw had been incorporated (mean 1.09 g/100 g) rather than burnt (mean 0.89 g/100 g), and a strong positive relationship between organic carbon and fertilizer N rate (r2 = 93.2%, P < 0.01). There was a detectable effect of fertilizer N on readily mineralizable N in the plough layer at both Gleadthorpe (P < 0.001) and Morley (P < 0.05). At Morley, there was a consistent trend (P = 0.06) for readily mineralizable N to be higher where straw had been incorporated rather than burnt, indicating that ploughing-in residues may contribute to soil nitrogen supply over the longer term.
  • Authors:
    • Blackshaw, R. E.
    • Anderson, R. L.
    • Derksen, D. A.
    • Maxwell, B.
  • Source: Agronomy Journal
  • Volume: 94
  • Issue: 2
  • Year: 2002
  • Summary: Cropping systems in the northern Great Plains (NGP) have evolved from wheat Triticum aestivum L.)-fallow rotations to diversified cropping sequences. Diversification and continuous cropping have largely been a consequence of soil moisture saved through the adoption of conservation tillage. Consequently, weed communities have changed and, in some cases, become resistant to commonly used herbicides, thus increasing the complexity of managing weeds. The sustainability of diverse reduced tillage systems in the NGP depends on the development of economical and effective weed management systems. Utilizing the principle of varying selection pressure to keep weed communities off balance has reduced weed densities, minimized crop yield losses, and inhibited adverse community changes toward difficult-to-control species. Varied selection pressure was best achieved with a diverse cropping system where crop seeding date, perennation, and species and herbicide mode of action and use pattern were inherently varied. Novel approaches to cropping systems, including balancing rotations between cereal and broadleaf crops, reducing herbicide inputs, organic production, fall-seeded dormant canola (Brassica napus and B. rapa), and the use of cover crops and perennial forages, are discussed in light of potential systems-level benefits for weed management.
  • Authors:
    • Mrabet, R.
  • Source: Conservation Agriculture, a Worldwide Challenge
  • Volume: 2
  • Year: 2001
  • Summary: This paper discusses the benefits of changing from actual agricultural systems to no-tillage for Moroccan dry farming. Recent findings showed that no-tillage cropping systems are the best ways to manage risk and improve efficiency and accordingly present two major agronomic advantages: (i) sustain or maintain crop productivity vis-a-vis variations in climate while reducing costs and natural resource degradation; and (ii) diverse crops and intensify the rotation to meet farmer's needs while maintaining a protective residue cover to curb erosion and evaporation and enhance water and nutrient use efficiency. Technological developments in machinery will increase adaptation to adverse soil and climate conditions. Improvements in no-till drill design, which focus on proper seed and fertilizer placement, are needed and national no-till drill industry should be favoured.
  • Authors:
    • Power, J. F.
    • Wiese, R.
    • Flowerday, D.
  • Source: Journal of Environmental Quality
  • Volume: 30
  • Issue: 6
  • Year: 2001
  • Summary: The U.S. Department of Agriculture funded the Management Systems Evaluation Area (MSEA) research project in 1990 to evaluate effectiveness of present fanning systems in controlling nitrate N in water resources and to develop improved technologies for farming systems. This paper summarizes published research results of a five-year effort. Most research is focused on evaluating the effectiveness of farming system components (fertilizer, tillage, water control, cropping systems, and soil and weather variability). The research results show that current soil nitrate tests reliably predict fertilizer N needed to control environmental and economic risks for crop production. A corn (Zea mays L.)-soybean [Glycine mar (L.) Merr.] rotation usually controls risk better than continuous corn, but both may result in unacceptable nitrate leaching. Reduced tillage, especially ridge-till, is better than clean tillage in reducing risk. The drainage controls nitrate in ground water, but discharge may increase nitrate in surface waters. Sprinkler irrigation systems provide better water control than furrow irrigation because quantity and spatial variability of applied water is reduced. Present farming systems have two major deficiencies: (i) entire fields are managed uniformly, ignoring inherent soil variability within a field; and (ii) N fertilizer rates and many field practices are selected assuming normal weather for the coming season. Both deficiencies can contribute to nitrate leaching in parts of most fields.