• Authors:
    • Counce, P. C.
    • Gordon, E. C.
    • Keisling, T. C.
    • Oliver, L. R.
    • Manning, P. M.
    • Popp, M. P.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 34
  • Issue: 19/20
  • Year: 2003
  • Summary: Clay soils are difficult to manage to obtain a soyabean [ Glycine max (L.) Merr.] stand, especially when dry. A novel production system, recently observed on several farms in Arkansas, consists of bedding the dry clayey soil with disk-bedders, broadcasting the soyabean seed over the surface, re-bedding the seedbed to cover the seed, rolling the beds to flatten the tops and finally furrow irrigating immediately thereafter. Typically this planting system provides a stand of soyabean within 4 to 6 days after irrigation and is designated as "hipped" after the common reference of a disk-bedder as a hipper. Studies were conducted on Sharkey soil at Keiser, AR from 1998 to 2000 for comparing this "hipped" system to more widely used planting methods. On dry clayey soils, a randomized complete block design with three replications was used to compare full-season soyabean under a conventional 96-cm row system, drilled-planting into a stale seedbed, and the "hipped" system. A similar study for double-cropped wheat-soybean involved straw management (burn or leave) coupled with no-till drill, tilled drill, and "hipped" systems. Other small studies on the "hipped" system were conducted to investigate the sensitivity to planting depth, soyabean plant population, and suitability for obtaining a stand on other crops such as cotton [ Gossypium hirsutum (L.)] and grain sorghum [ Sorghum bicolor (L.) Moench]. The "hipped" system worked well for obtaining stands of soyabean, cotton, and grain sorghum. In essence the "hipped" system (1) provides insurance against poor planting conditions; (2) allows for a reduction in the uncertainty of planting and stand establishment time required; (3) can be used to achieve high plant populations; (4) requires a relatively higher seeding rate in double-crop than full-season systems; (5) shows promise for situations when wheat stubble burning becomes curtailed especially if planting can occur early to lead to improved canopy coverage and (6) leads to yield reductions in fields where depth of seed placement cannot be controlled easily.
  • Authors:
    • Pringle, H. C.,III
    • Martin, S. W.
  • Source: Journal of Cotton Science
  • Volume: 7
  • Issue: 4
  • Year: 2003
  • Summary: Deep tillage at a 45 angle has been a recommended practice since the mid-1970s on most Mississippi Delta cotton soils. This practice disrupts hard pans and allows deeper wetting of the soil profile with winter rainfall. The newest deep tillage "subsoiler" designs (Paratill, low-till parabolic) have the shank extending through the soil at an angle, thereby reducing soil surface disturbance and allowing the subsoiler to run under the row in the direction of the row, without the shank passing directly through the drill. Both centre pivot and furrow irrigation of cotton has expanded since the early 1980s. With intermittent rainfall, irrigation is supplemental and represents a type of insurance against yield uncertainty during extended periods of water deficit. Field experiments were conducted at Stoneville, Mississippi, USA, during 1994-2001, to determine the long-term effects of sprinkler irrigation and in-row subsoil tillage on cotton yield and economic return of cotton cultivars DES119 (1994-95), SG125 (1996-99) and SG747 (2000-01) on silt loam soil from 1994 to 2001. In-row subsoil tillage was performed with a low-till parabolic subsoiler and irrigation was applied with an overhead lateral-move sprinkler irrigation system. Production costs were calculated for direct costs and total specified costs excluding land rent, general farm overheads and returns to management. Average net returns were calculated as the difference between income at the cotton loan rate of $1.15 per kg of lint and total specified costs. Returns were maximized with either the irrigated, non-subsoiled or the non-irrigated, subsoiled environments. Lower returns occurred in the irrigated, subsoiled environment due to the higher costs and lack of yield increase.
  • Authors:
    • Tope, K. L.
    • Gaddis, S. E.
    • Petersen, B. E.
    • Sterner, R. T.
    • Poss, D. J.
  • Source: Crop Protection
  • Volume: 22
  • Issue: 4
  • Year: 2003
  • Summary: During 2000-2001, small mammals, birds, and potential corn/soybean damage were studied at a low-tillage, non-irrigated agricultural research site in the Colorado Piedmont. A small mammal survey involved four trapping sessions and 18, 12-live-trap grids each. Within years, two grids each were placed at random, fixed locations in experimental corn, fallow, millet, pea, soyabean, sunflower, and wheat plots at the site; two off-plot grids each were set at random, fixed locations
  • Authors:
    • Jones, R. H.
    • Leonard, B. R.
    • Gore, J.
  • Source: Environmental Entomology
  • Volume: 32
  • Issue: 1
  • Year: 2003
  • Summary: Field and laboratory studies evaluated the influence of selected crop hosts on Helicoverpa zea population dynamics in relation to genetically engineered Bt (Bollgard) and non-Bt cottons. Host specific H. zea colonies were initiated with a colony originally collected from sweetcorn. The colony was allowed to complete one generation on meridic diet then split into cohorts and allowed to complete one generation on field maize, grain sorghum, soyabean, cotton, or meridic diet in individual 29.5 ml plastic cups. During the first part of the study, larval developmental times, pupal weights, and survival were measured. H. zea survival was higher on meridic diet and grain sorghum than on soyabean and cotton. The development of H. zea larvae was faster on field maize than the other larval diets. Also, H. zea required a longer period of time to complete development on cotton than on the other hosts. Pupal weights were higher on meridic diet than the plant hosts. Pupal weights of H. zea that completed larval stadia on cotton were lower than on the other larval diets. Neonates (F 1) from each of the host specific colonies (200 per colony) were exposed to Bt and non-Bt cottons. Mortality of second generation H. zea on non-Bt and Bt cottons was measured at 96 h. H. zea larvae from the cotton colony had higher mortality on non-Bt cotton than the other host specific colonies except the grain sorghum colony. On Bt cotton, larvae from the maize colony had a higher level of mortality than larvae from the soyabean and grain sorghum colonies. These data provide valuable information for evaluating the contribution of cultivated hosts as additional, alternative refugia in Bt-cotton resistance management plans.
  • Authors:
    • Featherstone, A. M.
    • Langemeier, M. R.
    • Abdulkadri, A. O.
  • Source: Applied Economics
  • Volume: 35
  • Issue: 7
  • Year: 2003
  • Summary: The risk attitudes of dryland wheat, irrigated maize, and dairy producers in Kansas, USA, are examined using the nonlinear mean-standard deviation approach. Observations on farm characteristics, obtained from 1993-97, and the statewide market year average prices for wheat and maize from 1950-97, are used. Results of analyses indicated that dryland wheat and dairy producers are characterized by increasing absolute and increasing relative risk aversion while irrigated maize producers are characterized by constant absolute and increasing relative risk aversion. Both crop enterprises exhibited constant returns to scale technology while the dairy enterprise exhibited decreasing returns to scale. Gross farm income was significant and positively related to relative risk aversion.
  • Authors:
    • Bacon, R. K.
    • Gibbons, J.
    • Moldenhauer, K. A. K.
    • Windham, T. E.
    • Anders, M. M.
    • McNew, R. W.
    • Grantham, J.
    • Holzhauer, J.
  • Source: Research Series - Arkansas Agricultural Experiment Station
  • Issue: 504
  • Year: 2003
  • Summary: Rotation, tillage, and variety main effects on grain yield were all significant in 2002. Rice grain yield, over all treatment combinations, averaged 159 bu/acre, which was 22 bu/acre more than in 2001. Grain yields for the two 3-phase rotations were 180 bu/acre for the rice-corn-soybeans rotation and 177 bu/acre for the rice-corn (wheat)-soybean rotation. These yields were slightly better than the 174 bu/acre yield from the rice-soybean rotation and 165 bu/acre from the rice-corn rotation. Grain yield declined 13 bu/acre in the continuous rice treatments when compared to 2001 yields and 27 bu/acre from the 2000 yields. Plant growth was poor in all the continuous rice plots with leaf nitrogen (N) levels lower than in other rotations. Conventional tillage treatment combinations yielded 17 bu/acre more than the no-till combinations, but this difference varied between rotations. For the continuous rice rotation, the conventional-till yielded 37 bu/acre more than the no-till whereas the same difference was 14 bu/acre in the rice-soybean rotation. There was a non-significant 7 bu/acre increase in rice yield over all treatment combinations with the 'enhanced' fertility treatments when compared to the 'standard' fertility treatments. Wells yielded a non-significant 7 bu/acre better than LaGrue across all treatments. Rice grain yield from the two rotations where rice was planted after wheat averaged 144 bu/acre-significantly higher than any previous year. There was an overall yield loss of 12 bu/acre from no-till when compared to conventional tillage, a 4 bu/acre gain from increased fertility, and a 16 bu/acre gain from the variety XL-7 when compared to RU1093. Of all the treatment combinations in this comparison the no-till rice (wheat)-soybean (wheat) rotation using enhanced fertility and the variety XL-7 was the most productive with a rice yield of 181 bu/acre and a wheat yield of 77 bu/acre. Overall, irrigation-water use declined from the previous year with an average of 26 inches needed for the conventional till treatments and 24 inches for the no-till treatments. Continuous rice needed only 17 inches of irrigation while all other rotations required between 28 and 32 inches.
  • Authors:
    • Bundy, L. G.
    • Andraski, T. W.
    • Kilian, K. C.
  • Source: Journal of Environmental Quality
  • Volume: 32
  • Issue: 5
  • Year: 2003
  • Summary: Manure additions to cropland can reduce total P losses in runoff on well-drained soils due to increased infiltration and reduced soil erosion. Surface residue management in subsequent years may influence the long-term risk of P losses as the manure-supplied organic matter decomposes. The effects of manure history and long-term (8-yr) tillage [chisel plow (CP) and no-till (NT)] on P levels in runoff in continuous corn (Zea mays L.) were investigated on well-drained silt loam soils of southern and southwestern Wisconsin. Soil P levels (0-15 cm) increased with the frequency of manure applications and P stratification was greater near the surface (0-5 cm) in NT than CP. In CP, soil test P level was linearly related to dissolved P (24-105 g ha(-1)) and bioavailable P (64-272 g ha(-1)) loads in runoff, but not total P (653-1893 g ha(-1)). In NT, P loads were reduced by an average of 57% for dissolved P, 70% for bioavailable P, and 91% for total P compared with CP. This reduction was due to lower sediment concentrations and/or lower runoff volumes in NT. There was no relationship between soil test P levels and runoff P concentrations or loads in NT. Long-term manure P applications in excess of P removal by corn in CP systems ultimately increased the potential for greater dissolved and bioavailable P losses in runoff by increasing soil P levels. Maintaining high surface residue cover such as those found in long-term NT corn production systems can mitigate this risk in addition to reducing sediment and particulate P losses.
  • Authors:
    • Fielding, D. J.
    • Begna, S. H.
  • Source: Journal of Economic Entomology
  • Volume: 96
  • Issue: 4
  • Year: 2003
  • Summary: We characterized the type and extent of grasshopper injury to above- and below-ground plant parts for four crops, i.e. barley ( Hordeum vulgare), oats ( Avena sativa), wheat ( Triticum aestivum), and canola [turnip rape] ( Brassica campestris [ B. campestris var. oleifera]), commonly grown, or with potential to grow, in central Alaska, USA. Cages were placed on 48 pots containing plants in second to third leaf stages and stocked with 0, 2, 4, and 6 first-instar Melanoplus sanguinipes pot -1. Plants were harvested 22 days after planting. Stem growth of barley and oats was not affected except at the highest grasshopper treatment. In rape, stem biomass was reduced at the medium and high grasshopper treatments, when most of the leaves had been consumed. The highest grasshopper treatment reduced leaf area in barley and oats by ~55%, and caused a significant reduction in dry weight of leaves, stems, and roots (41-72%). Wheat and canola plants were smaller than barley and oats across all treatments and, at the highest grasshopper density, above-ground portions of wheat and canola were completely destroyed. Length and surface area of roots of barley and oats were reduced by 20-28% again at the highest grasshopper density, whereas the reduction for wheat and canola ranged from 50 to 90%. There was little or no difference among all grasshopper densities for C:N ratio in leaf and stem tissues of all crops. The results suggest that wheat and canola are more susceptible than barley and oats and that densities ≥2 pot -1 (~≥50 m -2) of even very small grasshoppers could cause significant damage in small-grain and oilseed crop production.
  • Authors:
    • Lokaj, G. R. W.
    • Majek, B. A.
    • Belding, R. D.
    • Hammerstedt, J.
    • Ayeni, A. O.
  • Source: HortTechnology
  • Volume: 13
  • Issue: 2
  • Year: 2003
  • Summary: Peach ( Prunus persica cv. Candor) trees were established and grown from 1996 to 1999 at the Rutgers Agricultural Research and Extension Center, Bridgeton, New Jersey, USA, to compare their performance under four methods of orchard floor preparation: flat no-till, flat cultivated, mound unmulched, and mound mulched orchard floors. The experimental site was flat and the soil was a well-drained Aura gravelly sandy loam (61% sand, 31% silt and 8% clay) with a pH of 6.5, cation exchange capacity of 5.7, and organic matter content of 2.0%. Soil moisture holding capacity and gas exchange capacity determine the efficacy of mounding in peach orchards. Under these conditions, the method of orchard floor preparation had no effect on peach tree trunk cross-sectional area, fruit number per tree, fruit size and yield. Thus, without irrigation, there was no advantage to the early performance of peach trees associated with orchard floor mounding on Aura gravelly sandy loam when situated on a flat terrain.
  • Authors:
    • Lyon, D. J.
    • Blumenthal, J. M.
    • Stroup, W. W.
  • Source: Agronomy Journal
  • Volume: 95
  • Issue: 4
  • Year: 2003
  • Summary: Dryland corn ( Zea mays L.) production increased more than 10-fold from 1995 through 2000 in semiarid western Nebraska. Corn population and N fertilizer management recommendations are needed for this area. The objectives of this study were to determine the influence of plant population and N fertility on corn yields in semiarid western Nebraska. In 1999 and 2000, experiments were conducted each year at four sites. Factorial experimental treatments were five plant populations (17 300, 27 200, 37 100, 46 900, and 56 800 plants ha -1) and five N fertilizer rates (0, 34, 67, 101, and 134 kg N ha -1) arranged in a randomized complete block with five blocks. Corn yields ranged from less than 100 kg ha -1 to more than 5550 kg ha -1. Overall, grain yield increased 353 kg ha -1 with increasing population from 17 300 to 27 200 plants ha -1. Population increases above 27 200 plants ha -1 resulted in inconsistent yield results. Nitrogen fertilization and plant population effects did not interact. Yields were maximized by 202 kg N ha -1 in the form of soil NO 3-N and fertilizer N available before crop emergence. Growers are advised to use a plant population of 27 200 plants ha -1. Economic optimal fertilizer rate can be estimated using the equation: Nfert.=(10.6 * Pcorn- Pfert.)/(0.0526 * Pcorn)- Nsoil, where Pcorn and Pfert. are corn and fertilizer price ($ kg -1), respectively, Nsoil is soil test NO 3-N (kg ha -1) as determined by preplant soil test in a 0- to 120-cm soil sample, and Nfert. is economic optimal fertilizer rate (kg ha -1).