• Authors:
    • Shen, Y.
    • Wang, X.
    • Zheng, L.
  • Source: Acta Prataculturae Sinica
  • Volume: 20
  • Issue: 4
  • Year: 2011
  • Summary: The research presented crop yield, phosphorus dynamic for a wheat-soybean rotation systems affected by tillage management: conventional tillage (t), tillage+ stubble retention (ts), no-till (nt), no-till+stubble retention (nts) in the Loess Plateau. Results showed that ten years tillage management implementation did not carry a yield penalty for winter wheat, soybean yield had a positive response to conservation tillage. Soil phosphorus content increased with the increasing of rotation sequences. Both total phosphorus and available phosphorus contents were increased at top 0-5 cm. Stubble retention increase crop phosphorus uptake, P contents in soybean grain under nts and ts treatment were 111% and 82% higher than that under t treatment. The results provide a local agricultural implement provides certain theoretical guidance.
  • Authors:
    • Pelissari, A.
    • Moraes, A.
    • Balbinot Junior, A.
    • Veiga, M.
    • Dieckow, J.
  • Source: Revista Brasileira de Agrociencia
  • Volume: 17
  • Issue: 1
  • Year: 2011
  • Summary: The objective of this study was to evaluate the effect of winter soil use on reminiscent straw on the soil, physical characteristic in superficial soil layer and maize performance cultivated in succession. One experiment was carried out in three places in the North Plateau of Santa Catarina State, Brazil, during 2006/07 crop season. Five alternatives of soil use in the winter were investigated: (1) multicropping with black oat+ryegrass+vetch+arrow leaf clover without grazing and nitrogen fertilization (multicropping cover); (2) the same multicropping, with grazing and nitrogen fertilization, 100 kg ha -1 of N (pasture with N); (3) the same multicropping, with grazing and without nitrogen fertilization (pasture without N); (4) oil seed radish, without grazing and nitrogen fertilization (oil seed radish); and (5) natural vegetation, without grazing and nitrogen fertilization (fallow). Higher straw dry mass was verified in multicropping cover. The winter annual pasture in crop-livestock system, cover crops and fallow did not affect the bulk density in 0,02 to 0,07 m of soil layer and maize performance in succession.
  • Authors:
    • Crusciol, C.
    • Calonego, J.
    • Castro, G.
  • Source: PESQUISA AGROPECUARIA BRASILEIRA
  • Volume: 46
  • Issue: 12
  • Year: 2011
  • Summary: The objective of this work was to evaluate the effects of crop rotation systems and liming materials on soil physical properties. The experiment was carried out from October 2006 to July 2008, in Botucatu, SP, Brazil, in a completely randomized block design in a split-plot arrangement with eight replicates. Main plots consisted of four crop rotation systems: soybean/fallow/maize/fallow, soybean/white-oat/maize/bean, soybean/millet/maize/pigeon pea and soybean/signal grass/maize/signal grass. Subplots consisted of the control treatment, without soil correction, and of the application of 3.8 Mg ha -1 of dolomitic lime (ECC=90%) or 4.1 Mg ha -1 of calcium-magnesium silicate (ECC=80%), on the surface of a clayed Rhodic Ferralsol. Aggregate stability, soil bulk density, total porosity, macro and microporosity, soil penetration resistance and moisture content were evaluated. Superficial application of the lime materials does not reduce soil aggregation and increases macroporosity down to 0.20 m, with calcium-magnesium silicate application, and to 0.10 m, when lime is applied. Soil under fallow in off-season decreases aggregate stability and increases soil penetration resistance in upper layers. The cultivation of Congo signal grass, between summer crops, increases aggregate stability down to 0.10-m depth.
  • Authors:
    • Eskandari, H.
  • Source: African Journal of Biotechnology
  • Volume: 10
  • Issue: 77
  • Year: 2011
  • Summary: Wheat ( Triticum aestivum) and bean ( Vicia faba L.) sole crops and their mixture in three planting pattern (M 1: alternate-row intercrop, M 2: within-row intercrop, M 3: mixed intercrop) were used to investigate the amount of resource consumption in terms of photosynthetically active radiation (PAR) interception, water and nutrient uptake. The experiment was carried out as randomized complete block design with four replications. The results show that intercropping systems had a significant effect on environmental resources consumption, where intercropping systems had more light interception and water, and nutrient uptake compared to sole crops, suggesting the complementarity effect of intercropping components in resources consumption. The ability of wheat and bean was different in intercropping systems in absorbing nutrients because of their differences in root morphology and cation exchange capacity. Regarding weed suppressions, intercrops were more effective than wheat sole crops, which were related to lower availability of environmental resources for weeds in intercropping systems.
  • Authors:
    • Cavariani, C.
    • Gazola, E.
  • Source: BIOSCIENCE JOURNAL
  • Volume: 27
  • Issue: 5
  • Year: 2011
  • Summary: The objective of this research was to evaluate crop yield and some characteristics and yield components of transgenic soybean cultivars sown after different winter cover crops in the first year under no tillage system. The experimental design was the completely randomized block with split plots and four replications. The main plots consisted of five winter cover crops, white oat ( Avena sativa L.), forage turnip ( Raphanus sativus L.), barley ( Hordeum vulgare L.), wheat ( Triticum aestivum L.) and ground pea ( Pisum sativum L.) and an area under fallow (spontaneous vegetation). The subplots consisted of six soybean cultivars (BRS 243 RR, BRS 245 RR, BRS 247 RR, BRS 255 RR, BRS 256 RR and BRS 244 RR). Variance analysis for agronomic characteristics showed that soybean yield components were influenced by the interaction between winter crop and soybean cultivar. Thus, final population, number of nodes and pods per plant, nodes dry matter per plant, number of grains per pod and grain yield were affected significantly. When soybean nodulation was evaluated, the treatment with the area under fallow showed lower values. There was difference among winter crops for BRS 243 RR grain yield, white oat showed the highest values.
  • Authors:
    • Sawargaonkar, G. L.
    • Gadade, G. D.
    • Shinde, V. S.
    • Gokhale, D. N.
    • Zade, K. K.
  • Source: Journal of Cotton Research and Development
  • Volume: 25
  • Issue: 2
  • Year: 2011
  • Summary: Field studies were carried out at Department of Agronomy, Marathwada Agricultural University, Parbhani during, 2007 to 2010 to explore the suitability of different soil moisture conservation and integrated nutrient management (INM) techniques in relation to yield and economics of Bt cotton under rainfed conditions. The results revealed that opening of furrow in alternate row recorded significantly highest seed cotton yield (2758, 2214 and 1452 kg/ha) as compared to cotton+straw mulching (2421, 2003 and 1233 kg/ha) and intercropping of cotton with soybean (2036, 1626 and 1106 kg/ha) treatments during the three year of experimentation respectively. However, intercropping of cotton+soybean recorded significantly highest seed cotton equivalent yield and thereby net returns and B:C ratio over wheat straw mulch and opening of furrow in alternate row. As regards to integrated nutrient management (INM) 100 per cent calculated RDF (100:50:30 N, P 2O 5 and K 2O kg/ha)+micronutrients (zinc, iron and boron) based on soil test recorded significantly highest seed cotton yield as compared to all other INM treatments. However, application of RDF with soil testing (75 per cent N, P 2O 5 and K 2O kg/ha through inorganic+25 per cent N, P 2O 5 and K 2O kg/ha through vermicompost) was next best treatment which recorded significantly highest seed cotton yield over rest of the treatments.
  • Authors:
    • Gowacka, A.
  • Source: Fragmenta Agronomica
  • Volume: 28
  • Issue: 3
  • Year: 2011
  • Summary: The field experiment was conducted in 2004-2006 on a farm in Frankamionka village, near Zamosc. The experiment was located on soil with silty dust grain composition, light acid, with average content of phosphorus and potassium, average content of organic matter (1.9%). The aim of the study was to determined the influence of strip intercropping of maize ( Zea mays L.) with common bean ( Phaseolus vulgaris L.) and spring wheat ( Triticum aestivum L.) on phosphorus and potassium concentration in maize and intake of macroelements with maize yield. The second factor were different methods of weeds regulation (mechanical, mechanical-chemical, chemical). The changes of phosphorus and potassium concentration in dependence of maize row position was also determined. Strip intercropping slightly increased level of phosphorus in corn. The concentrations of phosphorus and potassium in maize differ depending on rows position in strip. In maize from row neighboring with common bean phosphorus concentration was higher than in the next to spring wheat. But potassium concentrations was higher in inner rows. Mechanical method of weed regulation significantly increased concentration and intake of potassium as compared to mechanical-chemical and chemical method.
  • Authors:
    • Tomer, M.
    • Cambardella, C.
    • Singer, J.
    • Moorman, T.
    • Kovar, J.
  • Source: Journal of Environmental Quality
  • Volume: 40
  • Issue: 2
  • Year: 2011
  • Summary: Injection of liquid swine manure disturbs surface soil so that runoff from treated lands can transport sediment and nutrients to surface waters. We determined the effect of two manure application methods on P fate in a corn ( Zea mays L.)-soybean [ Glycine max (L.) Merr.] production system, with and without a winter rye ( Secale cereale L.)-oat ( Avena sativa L.) cover crop. Treatments included: (i) no manure; (ii) knife injection; and (iii) low-disturbance injection, each with and without the cover crop. Simulated rainfall runoff was analyzed for dissolved reactive P (DRP) and total P (TP). Rainfall was applied 8 d after manure application (early November) and again in May after emergence of the corn crop. Manure application increased soil bioavailable P in the 20- to 30-cm layer following knife injection and in the 5- to 20-cm layer following low-disturbance injection. The low-disturbance system caused less damage to the cover crop, so that P uptake was more than threefold greater. Losses of DRP were greater in both fall and spring following low-disturbance injection; however, application method had no effect on TP loads in runoff in either season. The cover crop reduced fall TP losses from plots with manure applied by either method. In spring, DRP losses were significantly higher from plots with the recently killed cover crop, but TP losses were not affected. Low-disturbance injection of swine manure into a standing cover crop can minimize plant damage and P losses in surface runoff while providing optimum P availability to a subsequent agronomic crop.
  • Authors:
    • Schuh, R.
    • Loffaguen, J.
    • Epping, J.
    • Costa, M.
    • Kunze, A.
    • Lovato, P.
  • Source: REVISTA BRASILEIRA DE CIENCIA DO SOLO
  • Volume: 35
  • Issue: 3
  • Year: 2011
  • Summary: Cover crops may difffer in the way they affect rhizosphere microbiota nutrient dynamics. The purpose of this study was to evaluate the effect of mycorrhizal and non-mycorrhizal cover crops on soil phosphatase activity and its persistence in subsequent crops. A three-year experiment was carried out with a Typic Quartzipsamment. Treatments were winter species, either mycorrhizal black oat ( Avena strigosa Schreb) or the non-mycorrhizal species oilseed radish ( Raphanus sativus L. var. oleiferus Metzg) and corn spurry ( Spergula arvensis L.). The control treatment consisted of resident vegetation (fallow in the winter season). In the summer, a mixture of pearl millet ( Pennisetum americanum L.) with sunnhemp ( Crotalaria juncea L.) or with soybean ( Glycine max L.) was sown in all plots. Soil cores (0-10 cm) and root samples were collected in six growing seasons (winter and summer of each year). Microbial biomass P was determined by the fumigation-extraction method and phosphatase activity using p-nitrophenyl-phosphate as enzyme substrate. During the flowering stage of the winter cover crops, acid phosphatase activity was 30-35% higher in soils with the non-mycorrhizal species oilseed radish, than in the control plots, regardless of the amount of P immobilized in microbial biomass. The values of enzyme activity were intermediate in the plots with corn spurry and black oat. Alkaline phosphatase activity was 10-fold lower and less sensitive to the treatments, despite the significant relationship between the two phosphatase activities. The effect of plant species on the soil enzyme profile continued in the subsequent periods, during the growth of mycorrhizal summer crops, after completion of the life cycle of the cover crops.
  • Authors:
    • Burdick, B. A.
    • Massey, R. E.
    • Nelson, K. A.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 3
  • Year: 2011
  • Summary: Early-seeded soybean [ Glycine max (L.) Merr.] relay intercropped into standing wheat ( Triticum aestivum L.) using soybean seed-coat technology may allow profitable wheat production in the Midwest on highly erodible soils. Dry conditions in mid- to late June have reduced relay intercropped soybean stands and yield in some years. We hypothesized that using glyphosate as a wheat harvest aid would reduce the impact of wheat interference on relay intercropped soybean grain yield and increase gross margins. Field research conducted over four site-years in upstate Missouri evaluated timings for application of glyphosate as a harvest aid on wheat and relay intercropped soybean. The cost effectiveness of these cropping systems was compared to full-season soybean, double-cropped wheat-soybean, and wheat-only production systems. Glyphosate applied to wheat 1 wk before harvest, after late dough, in a relay intercrop production system with coated-soybean maintained wheat grain yields similar to nontreated wheat, and increased soybean grain yields 290 to 770 kg ha -1 compared to nontreated wheat relay intercropped or double-cropped with soybean. Earlier glyphosate application timings (2-3 wk before wheat harvest) reduced wheat grain yields 10 to 25% and grain density 3 to 13%, but soybean yield increased 430 to 520 kg ha -1 compared to nontreated wheat in a relay intercrop system. A relay intercrop system with seed coat technology and glyphosate as a harvest aid may allow farmers to maintain wheat in their crop rotation while minimizing risk associated with early fall frost or dry conditions at seeding that may otherwise decrease double-crop soybean yields.