• Authors:
    • Spera, S.
    • Lhamby, J.
    • Santos, H.
  • Source: Ciencia Rural
  • Volume: 36
  • Issue: 1
  • Year: 2006
  • Summary: A 6-year (1997/98-2002/03) study was undertaken in Passo Fundo, Rio Grande do Sul, Brazil, to assess the effects of soil tillage systems and crop rotation systems on soyabean grain yield and its components. The treatments comprised 4 soil tillage systems: (1) no-tillage, (2) minimum tillage in winter and no-tillage in summer, (3) conventional tillage with a disc plough in winter and no-tillage in summer, and (4) tillage using a mouldboard plough in winter and no-tillage in summer; and 3 crop rotation systems (I) wheat/soyabean, (II) wheat/soyabean and common vetch [ Vicia sativa]/maize or sorghum, and (III) wheat/soyabean, common vetch/maize or sorghum and white oats/soyabean. The yield and weight of 1000 kernels of soyabean grown under no-tillage and minimum tillage was higher than those grown under conventional soil tillage with a disc plough and a mouldboard plough. Plant height was greater in the no-tillage system. The yield of soyabean grown after wheat in system II was higher than in soyabean grown after white oats and wheat in system III and after wheat in system I. The lowest soyabean yield, grain weight per plant and weight of 1000 kernels were obtained in monoculture (wheat/soyabean).
  • Authors:
    • Avila, A.
    • Spera, S.
    • Lhamby, J.
    • Santos, H.
  • Source: Bragantia
  • Volume: 65
  • Issue: 4
  • Year: 2006
  • Summary: The effects of soil management system and winter crop rotation on wheat yield and root diseases were assessed. Four soil management systems: (1) no-tillage, minimum tillage, conventional tillage using a disc plough plus disc harrow, and conventional tillage using a mouldboard plough plus disc harrow; and 3 crop rotation systems: wheat/soyabean, wheat/soyabean and common vetch [ Vicia sativa]/maize or sorghum ( Sorghum bicolor), and wheat/soyabean, white oat/soyabean and common vetch/maize or sorghum, were compared. The yield and plant height of wheat grown under no-tillage and minimum tillage were higher than the yield of wheat grown under conventional soil tillage using either disk plough or mouldboard plough. Weight of 1000 kernels was highest in the no-tillage. Crop rotation was efficient in reducing root diseases and in increasing wheat yield. The lowest wheat yield, grain weight per plant, 1000-kernel weight and test weight were obtained in monoculture (wheat/soyabean).
  • Authors:
    • Sweeney, D.
    • Kilgore, G.
    • Whitney, D.
    • Schwab, G.
  • Source: Agronomy Journal
  • Volume: 98
  • Issue: 3
  • Year: 2006
  • Summary: Reduced- and no-tillage seedbed preparation methods coupled with broadcast P applications lead to an accumulation of available P in the surface 0- to 5-cm soil layer and a depletion of available P deeper in the profile. A 3-yr study determined the effects of tillage and fertilizer P management on P uptake and grain yield for P-stratified soils. Tillage practices were moldboard plow (once at the start of the study followed by reduced tillage), reduced tillage (disk followed by field cultivation), and no-tillage. Four P management methods were imposed: (i) no P; (ii) 20 kg P ha -1 applied as a surface broadcast; (iii) 20 kg ha -1 applied as a banded starter, 5 cm to the side and 5 cm below the seed; or (iv) 20 kg ha -1 applied in a deep placed band, 13 to 15 cm on 0.7-m centers. The one-time moldboard plowing produced higher early season dry matter yields for corn ( Zea mays L.), wheat ( Triticum aestivum L.), and soybean [ Glycine max (L.) Merr.] compared with the no-tillage system, but tillage effects on final grain yield were inconsistent. Subsurface placement of P generally increased P uptake and grain yield of corn and sorghum [ Sorghum bicolor (L.) Moench], but had little effect on grain yield of soybean. Results indicate that subsurface applications of P fertilizers should be considered if soil test P is highly stratified within the surface 0- to 15-cm layer and the 15-cm composite is medium or below for available P.
  • Authors:
    • Ferguson, N.
    • Storrie, A.
    • Cook, T.
  • Source: Weed control in summer crops 2005-06
  • Year: 2006
  • Summary: This publication provides a guide to weed control in grain and forage sorghum, maize, sweetcorn, soyabean, sunflower, azuki bean [ Vigna angularis], cowpea, lablab, mung bean, pigeon pea, navy bean [ Phaseolus vulgaris], groundnut and millet in New South Wales, Australia. Information is presented on poison warnings, safety directions and first aid instructions on herbicide labels; successful use of herbicides; managing legal responsibilities in applying herbicides; testing for herbicide residues; tips for tankmixing herbicides; use of adjuvants, surfactants and oils with herbicides; water quality for herbicide application; reduction of herbicide spray loss (drift); nozzle selection for ground application; boomspray preparation and calibration; and cleaning and decontamination of boomsprays. Tabulated data are also given on the compatibility of herbicides with rotation and tillage practices to effectively control weeds affecting summer crops.
  • Authors:
    • Sisson, J.
    • Kirkham, M.
    • Sweeney, D.
  • Source: Agronomy Journal
  • Volume: 98
  • Issue: 3
  • Year: 2006
  • Summary: Annual row crop production on the naturally occurring claypan soils of the eastern Great Plains may require field operations during somewhat wet conditions and this potentially results in soil compaction by the commonly-used, heavy-weight tractors and equipment. The objectives of this experiment were (i) to determine if compaction reduced yield and growth of soybean [ Glycine max (L.) Merr.] and grain sorghum [ Sorghum bicolor (L.) Moench] grown on a claypan soil (fine, mixed, thermic Mollic Albaqualf) and (ii) to determine the effect of wheel tracks on selected soil properties and whether chisel plow tillage could reduce wheel-track compaction. Compaction treatments were (i) ALL - all of the plot compacted, (ii) WT - wheel-track compaction, (iii) WTC - wheel-track compaction followed by a chisel tillage operation, and (iv) NO - no intentional compaction. In general, it took until the third year of annually repeated compaction in the ALL treatment to reduce crop growth and yields compared with the NO compaction treatment. Even though nearly half of the area was compacted each year in the WT treatment, few measured crop parameters decreased. In wheel tracks, soil penetrometer resistance and bulk density increased and air permeability decreased compared with out of tracks. However, chisel tillage appeared to eliminate the compaction by reducing penetration resistance and bulk density and increasing air permeability to values similar to out of tracks. Thus, compaction of claypan soils may not often be a problem for producers in this area, especially if occasional chisel tillage is included to remove possible compacted zones.
  • Authors:
    • Andrioli, I.
    • Pereira, M.
    • Fabian, A.
    • Torres, J.
  • Source: Revista Brasileira de Agrociencia
  • Volume: 12
  • Issue: 1
  • Year: 2006
  • Summary: To evaluate the influence of vegetation coverings on soil temperature and humidity, in a medium texture red distrophic latossol, a study was conducted at CEFET-Uberaba, Minas Gerais, Brazil from January to June 2000. A ramdomized complete split plot block design, with 3 replications was used. Eight vegetation covers were allocated to plots: pearl millet ( Pennisetum americanum [ P. glaucum] sin. tiphoides), braquiaria ( Brachiaria brizantha [ Urochloa brizantha]), sorghum ( Sorghum bicolor), pigeon pea ( Cajanus cajan), sun hemp ( Crotalaria juncea) and black oat ( Avena strigosa [ A. nuda]), fallow land and area under conventional system (control). In subplots, maize and soyabean were planted, after vegetation cover desiccation. No significant differences were found among vegetation coverings in relation to soil hydric regime but differences among months were observed. Effect of vegetation cover on soil temperature was shown effectively during the months of May and June, in terms of residues of cultivated crops, mainly maize. Higher values in thermal amplitude were detected under soyabean cropping. Temperatures were higher at 5 cm depth than at 10 cm, in afternoons, under maize and soyabean cultivation.
  • Authors:
    • Prasad, J.
    • Challa, O.
    • Mandal, C.
    • Mandal, D. K.
  • Source: Agropedology
  • Volume: 16
  • Issue: 2
  • Year: 2006
  • Summary: The present study used water use efficiency (WUE) as an indicator of land quality index (LQI), through a composite Water Use Efficiency (GMWUE), on the line of land evaluation index of Food and Agriculture Organization. The GMWUE is a multiplicative function of WUE of individual crop/cropping system raised within a micro agro-edaphic environment (AEE). A relative LQI scale has been developed considering LQI for the most productive land as 100 and accordingly the LQI of other land has been fixed. The experimental cropping systems were cotton (sole), sorghum-wheat, soyabean-wheat, sorghum-gram and soyabean-gram for two years under normal rainfall in typical shrink-swell soils of Nagpur district of Maharashtra, India. The soyabean-wheat system had highest water use (WU) of 586.8 to 755.9 mm followed by sorghum-wheat, soyabean-gram, sorghum-gram and sole cotton. The WUE was highest for sole cotton (4.8-11.5 kg ha -1 mm -1) followed by soyabean-gram (3.7-10.16 kg ha -1 mm -1). The LQI in terms of GMWUE was 100 for Vertic Haplustepts occurring in the lower piedmont plain whereas it was 51 for Typic Haplustepts and 48 for Typic Haplusterts representing the upper piedmont and valley plain, respectively.
  • Authors:
    • Kumar, P.
    • Yadav, S. K.
    • Kumar, M.
    • Rinwa, R . S.
  • Source: Haryana Journal of Horticultural Sciences
  • Volume: 35
  • Issue: 3/4
  • Year: 2006
  • Summary: An experiment was conducted during 2003-04 and 2004-05 to study the nitrogen, phosphorus and potassium uptake by different cropping systems in semiarid tract of Haryana, India. The experiment comprised 7 cropping systems, viz., pearl millet-wheat, pearl millet-mustard, soyabean-wheat-cowpea, sorghum-wheat, pearl millet-potato-green gram, pearl millet-field pea-maize, and cotton-wheat. The uptake of nitrogen, phosphorus and potassium by the crops varied among different cropping systems. The nutrient uptake was higher in high yielding cropping systems. The nutrients uptake was highest in pearl millet-potato-green gram cropping system.
  • Authors:
    • Deen, W.
    • Janovicek, K.
    • Meyer-Aurich, A.
    • Weersink, A.
  • Source: Agronomy Journal
  • Volume: 98
  • Issue: 5
  • Year: 2006
  • Summary: The objective of our research was to identify economically efficient corn (Zea mays L.) based tillage-rotation combinations using a 20-yr data set from a long-term experiment in Ontario, Canada. Seven rotations in two tillage systems (moldboard and chisel plow) were analyzed. We found multiple benefits associated with diversifying rotations in both tillage systems The integration of soybean [Glycine mar (L.) Merr.] or soybean and wheat (Triticum aestivum L.) resulted in 7 to 11% higher corn yields in the chisel tillage system. In the plow tillage system corn yield in rotation with soybean and wheat increased by 5%, when wheat was underseeded with red clover (Trifolium pratense L.). These diversified rotations resulted in an increase in yearly net returns of $51 to $64 in the moldboard tillage system and $96 to $108 in the chisel tillage system. The diversification of rotations reduces variance of net return and thus makes the rotations attractive to risk averse producers. Furthermore diversified rotations showed less response to price changes. Diversified rotations evaluated in this study also proved to be less affected by increasing energy costs. Red clover seeded into wheat resulted in 5% higher yields for the following corn crop in the moldboard system. Rotations that included red clover cover lowered production risk but did not have higher net returns than comparable rotations without red clover. However, the potential for red clover to reduce N fertilization requirements for the following corn, was not considered in this study. Yield penalties due to chisel plowing with financial consequences were only observed in continuous corn. In all other rotations the effect of tillage was negligible. An increase in energy costs forces farmers to switch to crops with lower inputs rather than switch to reduced tillage.
  • Authors:
    • Kevan, P. G.
    • Belaoussoff, S.
    • Clements, D. R.
    • Murphy, S. D.
    • Swanton, C. J.
  • Source: Weed Science
  • Volume: 54
  • Issue: 1
  • Year: 2006
  • Summary: In a 6-yr study on four farms (36 fields) in Ontario, Canada, we tested the effects of tillage (moldboard, chisel plow, no tillage) and crop rotations (continuous corn, corn-soybean, corn-soybean-winter wheat) on emerged and seedbank weed species diversity and density Aside from the imposed experimental treatments, all other management was generally consistent among farms. Tillage had the largest effect on weed diversity and density. No tillage promoted the highest weed species diversity, chisel plow was intermediate, and moldboard plow resulted in the lowest species diversity. These results are consistent with ecological succession theory. The increase in weed species diversity resulted from 20 species being associated with no tillage systems, 15 of which were winter annuals, biennials, or perennials. Emerged weed density was affected only by tillage. Over 6 yr, seedbank declined in no-tillage systems from 41,000 to 8,000 seeds m(-3). Crop yields were not affected by tillage or crop rotation. In practical terms, reduced tillage in combination with a good crop rotation may reduce weed density and expenditures on weed management.