• 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:
    • 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:
    • 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:
    • Girija,A.
    • Khan,I. A.
    • Ramakrishna,Y. S.
    • Chary,G. R.
    • Vittal,K. P. R.
    • Sankar,G. R. M.
  • Source: Indian Journal of Dryland Agricultural Research and Development
  • Volume: 21
  • Issue: 2
  • Year: 2006
  • Summary: Sustainability indices of agricultural practices so far are developed independent of climatic effects. Especially under dry farming, the effect of rainfall is so overwhelming on the crop performance that this factor cannot be ignored while assessing for sustainability. In view of this, any sustainability index should be made independent of rainfall effect. Hence, a statistical measure of sustainability index 'eta', which is a function of estimate of error 'sigma' derived from a regression of yield through rainfall was developed. The 'eta' is a ratio between difference of mean and standard error (detrended for rainfall) to the maximum recorded yield during the period. Thus the limits of 'eta' are -1 to +1. The proposed procedure was utilized to arrive at sustainable practices from the data of All India Coordinated Research Project for Dryland Agriculture (India) field experiments conducted at both research station and on-farm from varying agroclimatic regions. The practices exceeding a sustainability yield index of 0.67 were considered as suitable for recommendation. The study indicated that barley, pearl millet, mustard, green gram, moth bean and cowpea had a moderate sustainability in arid conditions. Pearl millet at Akola (Maharashtra), pigeonpea and soybean at Indore (Madhya Pradesh) under wet semiarid conditions, and maize and horse gram at Arjia under dry semiarid conditions attained a moderate sustainability. Black gram, lentil and chickpea at Rewa (Madhya Pradesh), and lentil at Varanasi (Uttar Pradesh) also had moderate sustainability under dry subhumid conditions. A classification of superior genotypes of crops based on yield and sustainability and their variation under different climatic situations was made for cereals, pulses, oilseeds and vegetable and other crops. A grouping has also been made based on the variation of yield. Sustainability under different soils and climates and superior genotypes are identified. Some of the highly sustainable genotypes were Vandana of rice at Faizabad (Uttar Pradesh), RR-347-167 of rice at Ranchi, HUR-1095 of rice at Varanasi, BAU-2K-15 of linseed at Ranchi (Bihar), local variety of linseed at Rewa, AT-81 variety of sesame at Rajkot (Gujarat), HG-563 variety of cluster bean at Hisar (Haryana), S-1635 variety of mulberry at Bijapur (Karnataka) and SH-5 of sunn hemp at Hisar.
  • Authors:
    • McVay, K.
    • Langemeier, M.
    • Regehr, D.
    • Devlin, D.
    • Mankin, K.
    • Pierzynski, G.
    • Sweeney, D.
    • Janssen, K.
    • Zeimen, M.
  • Source: Journal of Soil and Water Conservation
  • Volume: 61
  • Issue: 5
  • Year: 2006
  • Summary: Best management practices have been recommended for controlling nutrient, herbicide, or sediment losses with surface runoff. This study was designed to determine the best overall combination of tillage and application practices to reduce surface losses from cropland. Runoff was collected from two Kansas sites in sorghum-soybean rotation during the 2001 to 2004 crop years and analysed for bioavailable phosphorus (P), soluble P, total P, ammonium, nitrate, total nitrogen (N), sediment, atrazine, and metolachlor concentrations. No-till treatments consistently experienced higher runoff water volumes than the chisel/disk tillage system used to warm and dry these clay soils in the spring. For this reason the no-till treatments also had higher nutrient and herbicide losses than chisel/disk tillage regardless of use of high or low application management techniques. The high included fertilizer and herbicide application practices intended to reduce losses with runoff while the standard application broadcast applied fertilizer and herbicide at planting. Few consistent differences were seen for pollutant loss between the high and standard application management. When average losses for all eight location-years were compared to chisel/disk low, soluble P losses were 3.0 and 2.1 times higher for no-till low and no-till high, respectively; metolachlor losses were 2.4 and 2.7 times higher for no-till low and no-till high, respectively; and atrazine losses were 4.8 and 6.1 times higher for no-till low and no-till high, respectively. The chisel/disk low did experience two times higher sediment losses compared with the no-till low or no-till high, when averaging over all eight location-years. However, tolerable soil loss was not exceeded, chisel/disk low generally had small losses for all tested pollutants and may be the best management combination to simultaneously reduce nutrient, herbicide, and sediment losses with cropland runoff for sites like those used in this study.
  • Authors:
    • Halvorson, A. D.
    • Reule, C. A.
  • Source: Agronomy Journal
  • Volume: 98
  • Issue: 5
  • Year: 2006
  • Summary: Irrigated, no-till (NT) production systems can potentially reduce soil erosion, fossil fuel consumption, and greenhouse gas emissions compared with conventional till (CT) systems. Including a legume in the rotation may also reduce N fertilizer requirements. Nitrogen fertilization (6 N rates) effects on irrigated, corn (Zea mays L.) and soybean [Glycine mar (L.) Merr.] yields in a corn-soybean rotation were evaluated for 5 yr on a clay loam soil to determine the viability of an irrigated NT system and N needs for optimum crop yield. Corn grain yields were significantly increased by N fertilization each of 3 yr in the rotation, but soybean grain yields (2 yr) did not respond to N fertilization, averaging 2.79 Mg ha(-1). Three year average corn grain yields were near maximum with an available N (AN) (soil + fertilizer + irrigation water N) level of 257 kg N ha(-1). Nitrogen use efficiency (NUE) by corn and soybean, based on grain N removal, decreased with increasing AN level and ranged from 155 to 46 and 88 to 18 kg grain kg(-1) AN for the low and high N treatments for corn and soybean, respectively. Estimated total N required to produce one Mg grain at maximum yield averaged 20 kg N for corn and 54 kg N for soybean. Corn residue increased with increasing N rate, but soybean residue was constant across N rates. Excellent irrigated, NT corn yields were obtained in this corn-soybean rotation for northern Colorado, but soybean yields were only marginally acceptable. Short soybean plant height (30-40 cm) and shattering made combine harvest difficult resulting in significant grain loss. Improved soybean cultivars are needed for this area to make a corn-soybean rotation a viable production system.
  • Authors:
    • Abney, T. S.
    • Vyn, T. J.
    • Stott, D. E.
    • Gal, A.
    • Omonode, R. A.
  • Source: Soil Science Society of America Journal
  • Volume: 70
  • Issue: 2
  • Year: 2006
  • Summary: For various reasons, North American crop farmers are more likely to practice limited-duration no-till than continuous no-till (NT). Little is known about effects of short-term no-till (ST-NT) on organic C and total N relative to NT and conventional-till systems. A field experiment was initiated in 1980 to study the effects of NT, chisel plow (CP), and moldboard plow in continuous corn (CC; Zeamays L.) and soybean (Glycinemax. L.)-corn (SC) rotations on dark prairie soil. In 1996, the moldboard treatments were split into a ST-NT subplot and an intermittently chisel-plowed (STI-CP) subplot that was chiseled only before corn. In 2003, soil samples were taken incrementally to the 1.0-m depth from NT, CP, ST-NT, and STI-CP plots. Soil C and N accumulation was unaffected by rotation system at any depth interval. Tillage treatments significantly affected soil C and N concentrations only in the upper 50 cm. On an equivalent soil mass basis, C storage to 1.0 m after 24 yr totaled 151 Mg ha21 in continuous NT, but just 108 Mg ha21 in continuous CP. Short-term no-till and STI-CP systems resulted in 26 and 21 Mg ha21, respectively, more soil C than CP. Total N storage was similar for NT and ST-NT systems, but was significantly lower (4 Mg ha21 less) with CP. Our results suggest that the combination of moldboard plowing (17 yr) followed by short-term (6-7 yr) no-till or intermittent chisel was generally superior to continuous chisel plowing (24 yr) in soil C and N contents.
  • Authors:
    • Kaspar, T. C.
    • Parkin, T. B.
  • Source: Journal of Environmental Quality
  • Volume: 35
  • Issue: 4
  • Year: 2006
  • Summary: Soil N2O emissions from three corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] systems in central Iowa were measured from the spring of 2003 through February 2005. The three managements systems evaluated were full-width tillage (fall chisel plow, spring disk), no-till, and no-till with a rye (Secale cereale L. Rymin') winter cover crop. Four replicate plots of each treatment were established within each crop of the rotation and both crops were present in each of the two growing seasons. Nitrous oxide fluxes were measured weekly during the periods of April through October, biweekly during March and November, and monthly in December, January, and February. Two polyvinyl chloride rings (30-cm diameter) were installed in each plot (in and between plant rows) and were used to support soil chambers during the gas flux measurements. Flux measurements were performed by placing vented chambers on the rings and collecting gas samples 0, 15, 30, and 45 min following chamber deployment. Nitrous oxide fluxes were computed from the change in N2O concentration with time, after accounting for diffusional constraints. We observed no significant tillage or cover crop effects on N2O flux in either year. In 2003 mean N2O fluxes were 2.7, 2.2, and 2.3 kg N2O-N ha-1 yr-1 from the soybean plots under chisel plow, no-till, and no-till + cover crop, respectively. Emissions from the chisel plow, no-till, and no-till + cover crop plots planted to corn averaged 10.2, 7.9, and 7.6 kg N2O-N ha-1 yr-1, respectively. In 2004 fluxes from both crops were higher than in 2003, but fluxes did not differ among the management systems. Fluxes from the corn plots were significantly higher than from the soybean plots in both years. Comparison of our results with estimates calculated using the Intergovernmental Panel on Climate Change default emission factor of 0.0125 indicate that the estimated fluxes underestimate measured emissions by a factor of 3 at our sites.
  • Authors:
    • Crow, T. R.
    • Liebman, M.
    • Asbjornsen, H.
    • Schulte, L. A.
  • Source: Journal of Soil and Water Conservation
  • Volume: 61
  • Issue: 6
  • Year: 2006
  • Authors:
    • Owens, L. B.
    • Shipitalo, M. J.
  • Source: Journal of Environmental Quality
  • Volume: 35
  • Issue: 6
  • Year: 2006