• Authors:
    • Marchetti, M.
    • Vitorino, A.
    • Souza, L.
    • Brandt, E.
  • Source: CIENCIA E AGROTECNOLOGIA
  • Volume: 30
  • Issue: 5
  • Year: 2006
  • Summary: The effects of crop rotation on the performance of soyabean were studied in Dourados, Mato Grosso do Sul, Brazil, during 1998, 1999 and 2000. The treatments were: maize/vetch/maize/vetch/soyabean, cotton/oat/cotton/sorghum/soyabean, soyabean/wheat/soyabean/maize/millet/soyabean, maize/grazing turnip/maize/sorghum/soyabean, maize/oat/maize/bean/millet/soyabean, rice/grazing turnip/rice/oat/soyabean, rice/sorghum/rice/bean/millet/soyabean, cotton/wheat/cotton/wheat/soyabean, and cotton/grazing turnip/cotton/oat/soyabean. Dry matter of aerial parts at the full flowering stage, plant height, first pod insertion, number of pods per plant, productivity and 1000-grain mass were evaluated. The rotation system had no significant effects on plant height, first pod insertion, and number of pods per plant. The highest grain yields were obtained under rice/sorghum/rice/bean/millet/soyabean and soyabean/wheat/soyabean/maize/millet/soyabean.
  • Authors:
    • Hons, F.
    • Dou, F.
  • Source: Soil Science Society of America Journal
  • Volume: 70
  • Issue: 6
  • Year: 2006
  • Summary: Management practices that alter plant residue production and distribution influence SOC (soil organic carbon) dynamics. The objectives of this study were to investigate the impacts of tillage, cropping system, and N fertilizer application on SOC and soil N pools through physical fractionation of a central Texas soil after 20 years. Nitrogen fertilizer application and no-tillage (NT) significantly increased wheat ( Triticum aestivum) straw yield. Compared with conventional tillage (CT), SOC under NT in surface (0-5 cm) samples was 38, 69, and 68% greater for continuous wheat (CW), wheat-soyabean ( Glycine max)-sorghum ( Sorghum bicolor) rotation (SWS), and double-cropped wheat-soyabean (WS), respectively. The greatest SOC was observed in WS under NT with N fertilizer application, and the lowest occurred in CW under CT without N. Increased cropping intensity increased SOC compared with monoculture. Nitrogen fertilizer application only significantly increased SOC sequestration under NT. No-tillage increased SOC concentration in all physical size fractions compared with CT. Increased cropping intensity and N fertilizer application significantly increased SOC sequestration in most size fractions only under NT. Intraparticulate organic matter C (IPOM-C) was proportionally more affected by tillage than total SOC, indicating that this fraction was more sensitive to management. Carbon concentrations in all size fractions were significantly correlated with each other as well as SOC. Our results indicated that NT associated with enhanced cropping intensity and N fertilizer application sequestered greater SOC and soil total N.
  • Authors:
    • Gallagher, L.
    • Armentrout, D.
    • Kratochvil, R.
    • Sardanelli, S.
    • Everts, K.
  • Source: Plant Disease
  • Volume: 90
  • Issue: 4
  • Year: 2006
  • Summary: Experiments using soil-incorporated cover crops and amendments of poultry litter (PL) and PL compost to suppress root-knot (RKN) and root-lesion nematodes were conducted in response to increasing nematode populations in Maryland's potato production areas. Identical experiments were established in microplots infested with Meloidogyne incognita or Pratylenchus penetrans. Treatments consisted of 12 3-year rotational sequences comprising potato (year 1) and cucumber (year 2) followed by a moderately RKN-resistant or susceptible soyabean cultivar, castor bean, grain sorghum, or sorghum sudangrass; PL or PL compost were amended to some of the RKN-susceptible soyabean and sorghum sudangrass plots. In the third year of the rotation, potato followed by soyabean was planted in all 12 treatments. The RKN-resistant soyabean, castor bean, sorghum sudangrass, and fallow or tillage decreased the populations of M. incognita compared with microplots where RKN-susceptible soyabean had been grown. However, RKN populations quickly recovered. Root-lesion nematode was reduced in the spring of 2001 following application of high rates of PL and PL compost in 2000. In the fall of 2001, sorghum sudangrass alone or in combination with PL or PL compost, grain sorghum, or fallow or tillage reduced root-lesion nematodes compared with either soyabean cultivar. No treatment affected root-lesion nematode the following year. The use of cover crops and PL compost is an effective method to reduce nematode populations only if successively incorporated into rotational cropping sequences.
  • Authors:
    • Gamero, C.
    • Rodrigues, J.
  • Source: Energia na Agricultura
  • Volume: 21
  • Issue: 4
  • Year: 2006
  • Summary: The present study aimed to evaluate the energy demand and the effective field capacity in different soil management systems, and three kinds of vegetal covering for soyabean cultivation. The experiment was carried out at the Lageado Experimental Farm, School of Agronomical Sciences, UNESP, Botucatu, SP, Brazil. The experimental area soil was classified as Red Dystroferric Nitosol. The experiment consisted of nine treatments combining three soil management systems (conventional, reduced and no-tillage) and three vegetal covering (black oats, sorghum and spontaneous vegetation). The experimental design was in randomized blocks, 3*3 factorial scheme with 4 replications, using Tukey's test at 5% to compare means. The soil management systems presented significant differences in the effective field capacity, fuel consumption per hour and operational consumption; the no-tillage system presented the best results, regardless of soil vegetal covering.
  • 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.