• Authors:
    • Payero, J. O.
    • Melvin, S. R.
    • Irmak, S.
    • Tarkalson, D.
  • Source: Agricultural Water Management
  • Volume: 84
  • Issue: 1-2
  • Year: 2006
  • Summary: Irrigation water supplies are decreasing in many areas of the US Great Plains, which is requiring many farmers to consider deficit-irrigating corn ( Zea mays L.) or growing crops like winter wheat ( Triticum aestivum L.) that require less water, but that are less profitable. The objectives of this study were to: (1) quantify the yield response of corn to deficit irrigation, and (2) determine which of several seasonal water variables correlated best to corn yield in a semiarid climate. Eight (T1-T8) and nine (T1-T9) deficit-irrigated treatments (including dryland), were compared in 2003 and 2004 in North Platte, Nebraska. The actual seasonal crop evapotranspiration (ET d) (calculated with procedures in FAO-56) for the different treatments was 37-79% in 2003 and 63-91% in 2004 compared with the seasonal crop evapotranspiration when water is not limited (ET w). Quantitative relationships between grain yield and several seasonal water variables were developed. Water variables included, irrigation ( I), total water ( Wall), rain+irrigation ( WR+I ), evaporation ( E), crop evapotranspiration (ET d), crop transpiration ( Td), and the ratios of ET d and Td to evapotranspiration and transpiration when water is not limited (ET w and Tw). Both years, yield increased linearly with seasonal irrigation, but the relationship varied from year to year. Combining data from both years, ET d had the best correlation to grain yield (yield=0.028ET d-5.04, R2=0.95), and the water variables could be ranked from higher to lower R2 when related to grain yield as: ET d ( R2=0.95) > Td ( R2=0.93) > ET d/ET w ( R2=0.90) = Td/ Tw ( R2=0.90) > Wall ( R2=0.89) > E ( R2=0.75) > WR+I ( R2=0.65) > I ( R2=0.06). Crop water productivity (CWP) (yield per unit ET d) linearly increased with ET d/ET w ( R2=0.75), which suggests that trying to increase CWP by deficit-irrigating corn is not a good strategy under the conditions of this study.
  • Authors:
    • Varma, M.
    • Rawat, S.
  • Source: International Journal of Agricultural Sciences
  • Volume: 2
  • Issue: 1
  • Year: 2006
  • Summary: A performance evaluation of zero-till-ferti-seed drill with conventional and reduced tillage method by sowing of wheat ( Triticum aestivum) was conducted, and was compared with the conventional system in terms of economics and energy consumption. The Pantnagar zero-till ferti-seed drill was developed by the G. B. Pant University of Agriculture and Technology, Pantnagar, Uttaranchal, India, and was made of mild steel angle iron 68.0*68.0*8 mm with square cross-section. Spacing between two furrow openers was 22.5 cm having 9 furrows. The treatments were: (T1) disc harrowing *2 + cultivation with planking *1 + planking *1 + seeding by seed-cum-ferti-drill; (T2) disc harrowing *1 + cultivating with planking *1 + planking *1 + seeding by seed-cum-ferti-drill; and (T3) zero-till-ferti-seed-drill. The initial moisture content and bulk density were maximum in T3. The field capacity of zero-till-ferti-seed-drill was found slightly higher than other treatments, but field efficiency was less due to presence of crop residue and no seedbed preparation. Fuel consumption in tillage and seeding system was very less i.e. 5.88 l/ha in T3 system in comparison to other treatments which indicates much saving of fuel in zero-till-ferti-seed-drill system. Wheat crop can be grown 10-15 days early that will result in timing sowing of wheat wheat crop and increases in yield. Another advantages of zero tillage is that it reduces cost of irrigation which was more economical in comparison to conventional method of sowing.
  • Authors:
    • Waddell, J.
    • Lenssen, A.
    • Sainju, U. M.
    • Caesar-Tonthat, T.
  • Source: Soil Science Society of America Journal
  • Volume: 70
  • Issue: 2
  • Year: 2006
  • Summary: Sustainable management practices are needed to enhance soil productivity in degraded dryland soils in the northern Great Plains. We examined the effects of two tillage practices [conventional till (CT) and no-till (NT)], five crop rotations [continuous spring wheat (Triticum aestivum L.) (CW), spring wheat-fallow (W-F), spring wheat-lentil (Lens culinaris Medic.) (W-L), spring wheat-spring wheat-fallow (W-W-F), and spring wheat-pea (Pisum sativum L.)fallow (W-P-F)], and a Conservation Reserve Program (CRP) on plant biomass returned to the soil, residue C and N, and soil organic C (SOC), soil total N (STN), and particulate organic C and N (POC and PON) at the 0- to 20-cm depth. A field experiment was conducted in a mixture of Scobey clay loam (fine, smectitic, frigid Aridic Argiustolls) and Kevin clay loam (fine-loamy, mixed, superactive, frigid Aridic Argiustolls) from 1998 to 2003 near Havre, MT. Mean annualized plant biomass returned to the soil from 1998 to 2003 was greater in W-F (2.02 Mg ha(-1)) than in W-L and W-W-F, regardless of tillage. In 2004, residue cover was greater in CW (60%) than in other rotations, except in W-W-E Residue amount and C and N contents were greater in NT with CW (2.47 Mg ha(-1) and 963 and 22 kg ha(-1), respectively) than in NT with W-L and CT with other crop rotations. The POC at 0 to 5 cm was greater in W-W-F and W-P-F (2.1-2.2 Mg ha(-1)) than in W-L. Similarly, STN at 5 to 20 cm was greater in CT with W-L (2.21 Mg ha(-1)) than in other treatments, except in NT with W-W-E Reduced tillage and increased cropping intensity, such as NT with CW and W-L, conserved C and N in dryland soils and crop residue better than the traditional practice, CT with W-F, and their contents were similar to or better than in CRP planting.
  • Authors:
    • Lenssen, A.
    • Caesar-Thonthat, T.
    • Waddell, J.
    • Sainju, U. M.
  • Source: Journal of Environmental Quality
  • Volume: 35
  • Issue: 4
  • Year: 2006
  • Summary: Long-term use of conventional tillage and wheat (Triticum aestivum L.)-fallow systems in the northern Great Plains have resulted in low soil organic carbon (SOC) levels. We examined the effects of two tillage practices [conventional till (CT) and no-till (NT)], five crop rotations [continuous spring wheat (CW), spring wheat-fallow (W-F), spring wheat-lentil (Lens culinaris Medic.) (W-L), spring wheat-spring wheat-fallow (W-W-F), and spring wheat-pea (Pisum sativum L.)-fallow (W-P-F)], and Conservation Reserve Program (CRP) planting on plant C input, SOC, and particulate organic carbon (POC). A field experiment was conducted in a mixture of Scobey clay loam (fine-loamy, mixed, Aridic Argiborolls) and Kevin clay loam (fine, montmorillonitic, Aridic Argiborolls) from 1998 to 2003 in Havre, MT. Total plant biomass returned to the soil from 1998 to 2003 was greater in CW (15.5 Mg ha(-1)) than in other rotations. Residue cover, amount, and C content in 2004 were 33 to 86% greater in NT than in CT and greater in CRP than in crop rotations. Residue amount (2.47 Mg ha(-1)) and C content (0.96 Mg ha(-1)) were greater in NT with CW than in other treatments, except in CT with CRP and W-F and in NT with CRP and W-W-E The SOC at the 0- to 5-cm depth was 23% greater in NT (6.4 Mg ha(-1)) than in CT. The POC was not influenced by tillage and crop rotation, but POC to SOC ratio at the 0- to 20-cm depth was greater in NT with W-L (369 g kg(-1) SOC) than in CT with CW, W-F, and W-L. From 1998 to 2003, SOC at the 0- to 20-cm depth decreased by 4% in CT but increased by 3% in NT. Carbon can be sequestered in dryland soils and plant residue in areas previously under CRP using reduced tillage and increased cropping intensity, such as NT with CW, compared with traditional practice, such as CT with W-F system, and the content can be similar to that in CRP planting.
  • Authors:
    • Sankar, G.
    • Vittal, K.
    • Chary, G.
    • Ramakrishna, Y.
    • Girija, A.
  • Source: Indian Journal of Dryland Agricultural Research and Development
  • Volume: 21
  • Issue: 1
  • Year: 2006
  • Summary: The data of 48 field experiments conducted during 1999 to 2003 under on-station conditions for assessing the tillage requirements of 5 cereals (rice, wheat, maize, pearl millet and finger millet), 2 oilseeds (groundnut and soyabean) and one pulse crop (cluster bean) under different soil and climatic conditions at 13 centres of All India Coordinated Research Project for Dryland Agriculture are presented. Based on the data generated from field experiments with conventional tillage, low tillage + hand weeding and low tillage + herbicide application, a detailed statistical assessment of superiority of tillage practices was conducted. Results indicated that conventional tillage was superior at Bangalore, Karnataka for finger millet under semiarid Alfisols; peal millet under semiarid Vertisols of Solapur, Maharashtra and arid Inceptisols of Agra, Uttar Pradesh; rice under moist subhumid Oxisols of Phulbani, Orissa and dry subhumid Inceptisols of Varanasi, Uttar Pradesh; maize under dry subhumid Inceptisols of Rakh Dhiansar, Jammu and Kashmir; wheat under moist subhumid Inceptisols of Ballowal Saunkhri, Punjab; and soyabean under semiarid Vertisols of Indore, Madhya Pradesh. Low tillage + herbicide application was found to be superior for rice under humid Oxisols of Ranchi, Jharkhand; maize under dry subhumid Inceptisols of Ballowal Saunkhri; soyabean under moist subhumid Vertisols of Rewa; and cluster bean under semiarid Aridisols of Dantiwada. LOw tillage + hand weeding was found to be superior for pearl millet under semiarid Aridisols of Hisar, Haryana and groundnut under semiarid Alfisols of Anantapur, Andhra Pradesh.
  • Authors:
    • Hergert, G. W.
    • Tarkalson, D. D.
    • Cassman, K. G.
  • Source: Agronomy Journal
  • Volume: 98
  • Issue: 1
  • Year: 2006
  • Summary: Tillage systems and nutrient management influence soil chemical properties that can impact the long-term sustainability of dryland production systems. This study was conducted to compare the effects of no-till (NT) and conventional till (CT) on the soil chemical properties and grain yield of a dryland winter wheat ( Triticum aestivum L.)-grain sorghum [ Sorghum bicolor (L.) Moench]/corn ( Zea mays L.)-fallow rotation. The effects of tillage practice over a 27-yr period (1962-1989) and the effect of the conversion of CT to NT over a 14-yr period (1989-2003) on selected soil chemical properties [pH, cation exchange capacity (CEC), base saturation (BS), soil organic C (SOC), K, Ca, Mg, and Bray-P] at different soil depths was determined. The acidification rate of the NT treatment from 1962 to 2003 was also determined. The study was conducted at North Platte, NE on a Holdrege silt loam (fine-silty, mixed, mesic Typic Argiustolls). In 1989, there were differences in soil chemical properties between CT and NT at some depths after 27 yr. However, in 2003, 14 yr after converting from CT to NT, there were no differences in the soil chemical properties compared with continuous NT. In 1989 and 2003, the soil chemical properties varied with soil depth. The acidification rate from 1962 to 2003 for the NT treatment in the 0- to 15-cm depth was 1.3 kmol H + ha -1 yr -1. This rate of acidification represents 38% of the total potential acidity from N fertilizer applications over 41 yr. Acidification was attributed to nitrification of ammonium-based fertilizers and leaching of NO 3-. Long-term winter wheat (1966-1983) and grain sorghum (1964-1988) grain yields were higher for NT (2718 and 4125 kg ha -1) than CT (2421 and 3062 kg ha -1). Retention of soil moisture as a result of increased residue cover under NT likely contributed to higher NT yields. Soil chemical properties in the wheat-sorghum/corn-fallow rotation will likely continue to change as a result of current management practices. Lime additions may become necessary in the future to ensure the sustainability of crop production in this system.
  • Authors:
    • Cassman, K. G.
    • Hergert, G. W.
    • Payero, J. O.
    • Tarkalson, D. D.
  • Source: Plant and Soil
  • Volume: 283
  • Issue: 1-2
  • Year: 2006
  • Summary: Soil pH is decreasing in many soils in the semiarid Great Plains of the United States under dry land no-till (NT) cropping systems. This study was conducted to determine the rate of acidification and the causes of the acidification of a soil cropped to a winter wheat (Triticum aestivum L.)-grain sorghum [Sorghum bicolor (L.) Moench]/corn (Zea mays L.)-fallow rotation (W-S/C-F) under NT. The study was conducted from 1989 to 2003 on soil with a long-term history of either continuous NT management [NT(LT)] (1962-2003) or conventional tillage (CT) (1962-1988) then converted to NT [NT(C)] (1989-2003). Nitrogen was applied as ammonium nitrate (AN) at a rate of 23 kg N ha(-1)supercript stop in 1989 and as urea ammonium nitrate (UAN) at an average annual rate of 50 kg N ha(-1) from 1990 to 2003 for both NT treatments. Soil samples were collected at depth increments of 0-5, 5-10, 10-15, and 15-30 cm in the spring of 1989 and 2003. Acidification rates for the NT(LT) and NT(C) treatments were 1.13 and 1.48 kmol H+ ha(-1) yr(-1) in the 0-30 cm depth, respectively. The amount of CaCO3 needed to neutralize the acidification is 57 and 74 kg ha(-1) yr(-1) for the NT(LT) and NT(C) treatments, respectively. A proton budget estimated by the Helyar and Porter [1989, Soil Acidity and Plant Growth, Academic Press] method indicated that NO3- leaching from the 30 cm depth was a primary cause of long-term acidification in this soil. Nitrate leaching accounted for 59 and 66% of the H+ from the acid causing factors for NT(LT) and NT(C) treatments, respectively. The addition of crop residues to the soil neutralized 62 and 47% of the acidity produced from the leaching of NO3-, and 37 and 31% of the acid resulting from NO3- leaching and the other acid-causing constituents for the NT(LT) and NT(C) treatments, respectively. These results document that surface soils in dry land W-S/C-F rotations under NT are acidifying under current management practices. Improved management to increase nitrogen uptake efficiency from applied fertilizer would help reduce the rate of acidification. The addition of lime materials to prevent negative impacts on grain yields may be necessary in the future under current management practices.
  • Authors:
    • Cantero-Martinez, C.
    • Westfall, D. G.
    • Sherrod, L. A.
    • Peterson, G. A.
  • Source: Journal of Soil and Water Conservation
  • Volume: 61
  • Issue: 2
  • Year: 2006
  • Summary: The presence of crop residue is an important component of dryland cropping systems management in the semiarid environment where soil erosion by wind is a major soil degradation process. Residue also affects precipitation capture and runoff. Long-term residue quantity dynamics of different cropping systems has not been studied in the semi-arid environment of the western Great Plains. Long-term studies were conducted in eastern Colorado, USA to determine the interaction of no-till cropping systems, soils, and climatic gradient on the production, retention, and disappearance of crop residue over a 12-year period. The cropping systems evaluated were winter wheat ( Triticum aestivum)-summer fallow (WF), winter wheat-maize ( Zea mays) or sorghum ( Sorghum bicolor)-summer fallow (WC/SF), winter wheat-maize/sorghum-millet ( Panicum miliaceum)-summer fallow (WC/SMF), and continuous cropping (CC). A soil surface residue base was achieved in a few years (four to five) and changed little over time. However, as cropping intensity increased the total crop residue retained on the soil surface increased as the proportion of fallow time decreased; a general trend was for residue levels to increase slowly. However, in the winter wheat-summer fallow system residue levels showed a trend to decrease after the initial base was achieved. Greater residue production and retention occurred on the toeslope soil position because these soils are deeper, have greater water holding capacity, and receive run-on water from upslope positions. Residue disappearance was less in the fallow period before maize planting compared to before wheat planting due to the greater fallow period, which included summer fallow in the wheat system. Residue loss was greater during the crop production periods as compared to the fallow periods. The levels of residue present on the soil surface in our intensive no-till cropping systems were generally adequate to control erosion by wind. However, at our high potential evapotranspiration site the residue levels were "marginal" for adequate wind erosion abatement, particularly in the winter wheat-summer fallow system. A combination of no-till management and increased cropping intensity (greater than winter wheat-summer fallow) is the key to sustainable production and soil conservation in this semi-arid environment.
  • Authors:
    • Valdes, G. S. B.
    • Lee, H. C.
    • Cook, H. F.
  • Source: Soil & Tillage Research
  • Volume: 91
  • Issue: 1-2
  • Year: 2006
  • Summary: Application of organic amendment to the soil surface is widely used in order to ameliorate topsoil physical conditions, especially with respect to temperature, evaporation and water content. Water intercepted by mulch and crop canopy involves loss through evaporation that never replenishes the soil water. In this study, hydrological and temperature conditions beneath mulches of manufactured materials, organic waste, wheat straw ( Triticum aestivum L.) and soybean straw ( Glycine max L. Merrill) applied at different thickness were investigated in glasshouse and field conditions in southern England. Interception loss by a maize ( Zea mays L.) canopy and mulch modified the soil water balance by adversely affecting soil water content beneath thicker application. Mulching had a beneficial effect on soil water and temperature regimes. These findings are important for identifying mulching practices for dryland agriculture and under scenarios of climatic change that predict lower rainfall and higher temperatures in summer.
  • Authors:
    • Gill, M.
    • Sarlach, R.
  • Source: Environment and Ecology
  • Volume: 24
  • Issue: 1
  • Year: 2006
  • Summary: The kandi region comprising 0.5 m ha (about 9.5%) of Punjab, India, is characterized undulated topography, light soil texture, heavy run off and soil erosion losses, poor moisture retentivity and devoid of easily exploitable underground water sources, and is therefore highly dependent upon seasonal south-west monsoon (July-September). It is coupled with poor infrastructure of roads and marketing, illiteracy, heavy cattle and human population pressure and agriculture adopted as subsidiary occupation. About 25-40% of the monsoon rains is lost as run off. The soils are non-saline, organic carbon averages 0.24% in loamy sand and 0.30 or more in sandy loam soils. The corresponding values of moisture retention at 1/3 bar or field capacity range from 8.1 to 15.8% and at 15 bar (permanent wilting point) from 3.7 to 4.8% in 0-180 cm soil layer of loamy sand soil and 16.2 to 21.5% and 3.7 to 7.6% respectively in sandy loam soil. In situ soil moisture conservation with the minor leveling, bunding and installation of suitable water structure helped to increase the yield of wheat [ Triticum aestivum] + gram [ Vigna mungo] by 57% and pearl millet by 25%. In light soil, green manuring during kharif gave an edge of 0.5 q/ha over the fallow fields on account of more rain water conservation and addition of green matter in soil. Mulching in standing maize [ Zea maize] in kharif helped to conserve the moisture in seed zone (0-15 cm) layer and ensured germination of succeeding wheat crop. Using the stored water in ponds during rainy season and its use as light irrigation (5 cm) at the initial moisture stress or as life saving irrigation, resulted in the better establishment of crops and increased the yield by 669 kg/ha over the controlled un-irrigated plots. Amongst the various crops, management practices conserving the soil moisture during kharif season and taking winter season crop were found promising technologies. Raya grown as an inter-rowcrop at 2.0 to 2.5 meter interval gave 2.5 q/ha seed yield. Application of fertilizer under dry land conditions seemed to be a prerequisite. It improved the above-, and below-, ground biomass and helped extend the root system to exploit water from deeper layer of soils and enabled the crop sustain the drought better and resulted in 50-70% grain yield increases in combination with fertilizer application. Under such an approach, fertilizer schedule for wheat was established at 80-40-20; N-P 2O 5-K 2O kg/ha in medium to heavy soil; and 40-20-10; N-P 2O 5-K 2O kg/ha for wheat or wheat+gram for light soils while the fodder ( kharif) and raya required just about 50 kg. N/ha.