• 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:
    • Orr, W.
    • Cooper, J.
    • Chataway, R.
    • Cowan, R.
  • Source: Animal Production Science
  • Volume: 51
  • Issue: 10
  • Year: 2011
  • Summary: Dairy farms located in the subtropical cereal belt of Australia rely on winter and summer cereal crops, rather than pastures, for their forage base. Crops are mostly established in tilled seedbeds and the system is vulnerable to fertility decline and water erosion, particularly over summer fallows. Field studies were conducted over 5 years on contrasting soil types, a Vertosol and Sodosol, in the 650-mm annual-rainfall zone to evaluate the benefits of a modified cropping program on forage productivity and the soil-resource base. Growing forage sorghum as a double-crop with oats increased total mean annual production over that of winter sole-crop systems by 40% and 100% on the Vertosol and Sodosol sites respectively. However, mean annual winter crop yield was halved and overall forage quality was lower. Ninety per cent of the variation in winter crop yield was attributable to fallow and in-crop rainfall. Replacing forage sorghum with the annual legume lablab reduced fertiliser nitrogen (N) requirements and increased forage N concentration, but reduced overall annual yield. Compared with sole-cropped oats, double-cropping reduced the risk of erosion by extending the duration of soil water deficits and increasing the time ground was under plant cover. When grown as a sole-crop, well fertilised forage sorghum achieved a mean annual cumulative yield of 9.64 and 6.05 t DM/ha on the Vertosol and Sodosol, respectively, being about twice that of sole-cropped oats. Forage sorghum established using zero-tillage practices and fertilised at 175 kg N/ha.crop achieved a significantly higher yield and forage N concentration than did the industry-standard forage sorghum (conventional tillage and 55 kg N/ha.crop) on the Vertosol but not on the Sodosol. On the Vertosol, mean annual yield increased from 5.65 to 9.64 t DM/ha (33 kg DM/kg N fertiliser applied above the base rate); the difference in the response between the two sites was attributed to soil type and fertiliser history. Changing both tillage practices and N-fertiliser rate had no affect on fallow water-storage efficiency but did improve fallow ground cover. When forage sorghum, grown as a sole crop, was replaced with lablab in 3 of the 5 years, overall forage N concentration increased significantly, and on the Vertosol, yield and soil nitrate-N reserves also increased significantly relative to industry-standard sorghum. All forage systems maintained or increased the concentration of soil nitrate-N (0-1.2-m soil layer) over the course of the study. Relative to sole-crop oats, alternative forage systems were generally beneficial to the concentration of surface-soil (0-0.1 m) organic carbon and systems that included sorghum showed most promise for increasing soil organic carbon concentration. We conclude that an emphasis on double- or summer sole-cropping rather than winter sole-cropping will advantage both farm productivity and the soil-resource base.
  • 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:
    • Maniutiu, D.
    • Indrea, D.
    • Muresan, A. O.
    • Sima, R.
  • Source: Journal of Horticulture, Forestry and Biotechnology
  • Volume: 15
  • Issue: 1
  • Year: 2011
  • Summary: In comparative stationary field experiments performed in Apahida, Cluj County, during four years (2005-2008), cabbage, sweet corn, carrot and garden bean crops have been followed on two different tillage systems: a conventional system - 5-6 tillage works including deep ploughing (25-28 cm deep) and 2-3 weeding, and the minimum tillage system: the strip-tillage cover crop system (spring fodder=oat+vetch) that was treated with Glyphosat herbicide (2 l/ha) and remained on the ground as mulch on which 10-15 cm wide sowing strips were split open. With the minimum tillage a 3-5 day delay in plant sprouting was noticed and vegetation was prolonged for few days in sweet corn, carrot and bean. Yield decreases by the minimum tillage vary between 7.7% and 16.7% in carrot and 5.0% and 10.9% in garden bean. In cabbage and sweet corn yield decrease was stated only during the first 2 years, while during the last 2 years the crop would balance on the two tillage methods. There was some product quality decrease with the minimum tillage, especially in carrots and beans.
  • Authors:
    • Dube, R. K.
    • Dhyani, S. K.
    • Sharma, A. R.
    • Ratan, S.
  • Source: Indian Journal of Agricultural Sciences
  • Volume: 81
  • Issue: 4
  • Year: 2011
  • Summary: A field experiment was conducted at Selakui, Dehradun during 2001-04 to study the effect of tillage (conventional and minimum) and mulching practices (no mulching and live mulching) under artificially created varying land slopes (0.5, 2.5, 4.5 and 9.5%) on soil-moisture conservation, productivity and nutrient uptake in maize ( Zea mays L.)-wheat ( Triticum aestivum L. emend Fiori & Paol.) cropping system. Sunnhemp ( Crotalaria juncea L.) intercropped with maize gave 0.87-1.09 tonnes biomass (dry weight) and accumulated 24.8-31.4 kg N/ha at 30 days of growth when it was mulched. Biomass and N accumulation generally decreased with increasing land slope and under minimum tillage. Maize performed better on moderate slopes (2.5-4.5%) than on the relatively flat (0.5%) and highly sloping land (9.5%). However, the yield of wheat decreased linearly and significantly with increasing slope due to less conservation of soil moisture on sloping lands during the previous rainy season. Conventional tillage gave significantly higher productivity of both maize and wheat than the minimum tillage. Intercropping of maize with sunnhemp and spreading the cut biomass as mulch at 30 days (live mulching) improved soil moisture conservation at maize harvest (+1.63 to 1.94%), and yield of maize (12.0%) as well as of following wheat (13.8%) compared with the no mulching.
  • Authors:
    • Goulart, R. Z.
    • Rocha, P. V. da
    • Santos, M. S. dos
    • Eltz, F. L. F.
    • Rocha, M. R. da
  • Source: REVISTA BRASILEIRA DE CIENCIA DO SOLO
  • Volume: 35
  • Issue: 4
  • Year: 2011
  • Summary: The watermelon is cultivated mainly by small producers, in sandy soils under conventional tillage, with occurrence of high erosion taxes, since the crop doesn't form canopy capable to cover the soil entirely. Watermelon ( Citrullus lanatus L.) was evaluated under different cultivation systems on an Ultisol in the Central Depression of RS, Brazil, in an experiment in the 2008/2009 growing season. On 48 m 2 plots in a randomized block design with four repetitions, the following cultivation systems were tested: conventional tillage (CT), no-tillage (NT), NT chiseled with one chisel shank (NT1S), NT chiseled with two shanks (NT2S), NT chiseled with three shanks (NT3S), NT chiseled with four shanks (NT4S), NT chiseled with five shanks (NT5S); the distance between chisel shanks was 0.35 m. Data were analyzed by the Duncan test (p6 kg), the root surface area and root system distribution in the soil profile perpendicular to the sowing line were determined 30 and 60 d after sowing. Besides, some soil physical properties (soil density and resistance to penetration) were determined after the watermelon cycle. The yield was highest under CT (126 t ha -1), differing statistically from the other treatments. The total root area increased with intensity and area of soil mobilization, except in the NT4S treatment. In the CT treatment, no difference in depth was observed, but in the other treatments the 0-5 cm layer differed from the deeper layers. Resistance to penetration in the 0-10 cm layer was lower, which may be related to the higher root concentration in that layer.
  • Authors:
    • Pimentel, I.
    • Gabardo, J.
    • Brondani, G.
    • Dionisio, J.
    • Motta, A.
    • Roveda, L.
    • Cuquel, F.
  • Source: Revista Brasileira de Agrociencia
  • Volume: 17
  • Issue: 3
  • Year: 2011
  • Summary: The reuse of industrial waste with low potential contaminant in agriculture is an important option for final disposal. To evaluate the agronomic potential of waste liquid from the production of enzymes (WLPE), set up an experiment in a Cambissoil cultivated under no tillage. There were two treatments (with and without the addition of 50 m 3 of WLPE). It was evaluated in soil pH CaCl 2, (H+Al), P, K, Ca, Mg and V% in 4 depths and in three samples of soil. The effects of three successive crops on the yield and nutrient content in the tissue: black bean ( Phaseolus vulgaris), a consortium of oat ( Avena strigosa)+forage turnip ( Raphanus sativus) and maize ( Zea mays L.). Increases in soil available P were observed, there were no changes in pH, (H+Al), K, Ca, Mg and V% using RLPE, and this provided no change in productivity in beans and corn, but a large increase in productivity and cycling of nutrients in plant cover (oat+turnip forage) were observed. There was no change in the concentration of nutrients in plant tissue of beans and oats+turnip indicating changes in nutritional status. The RLPE presented as an alternative for the supply of P, growth and cycling of nutrients in oats+turnip.
  • Authors:
    • Spera, S.
    • Fontaneli, R.
    • Santos, H.
    • Maldaner, G.
  • Source: PESQUISA AGROPECUARIA BRASILEIRA
  • Volume: 46
  • Issue: 10
  • Year: 2011
  • Summary: The objective of this work was to assess energy conversion and balance of integrated crop-livestock production systems, under no-tillage. The experiment was carried out from 2001 to 2008. From 2001 to 2002, the following systems were evaluated: 1, wheat/soybean, and black oat pasture+common vetch/corn; 2, wheat/soybean, and black oat pasture+common vetch+ryegrass/corn; 3, wheat/soybean and black oat pasture+common vetch/millet pasture; 4, wheat/soybean and black oat pasture+common vetch+rygrass/millet pasture; 5, wheat/soybean, white oat/soybean, and black oat pasture+common vetch/millet pasture; 6, wheat/soybean, white oat/soybean, and black oat pasture+common vetch+rygrass/millet pasture. From 2003 to 2008, the following systems were evaluated: 1, wheat/soybean, and common vetch/corn; 2, wheat/soybean, and black oat pasture/corn; 3, wheat/soybean, and black oat pasture/soybean; 4, wheat/soybean, and field pea/corn; 5, wheat/soybean, common vetch/soybean, and double purpose triticale/soybean; and 6, wheat/soybean, double purpose white oat/soybean, and double purpose wheat/soybean. Corn showed highest returned energy in comparison to the other grain crops, and to winter and summer annual pastures. Of the winter cover crops and green manure species evaluated, field pea was the most efficient in energy conversion. Systems 1, 2, and 4, from 2003 to 2008, had the most efficient energy balance.
  • Authors:
    • Goncalves, M.
    • Vitorino, A.
    • Souza, L.
    • Silva, D.
  • Source: Bragantia
  • Volume: 70
  • Issue: 1
  • Year: 2011
  • Summary: Soil physical degradation, like compaction, reduces water movement and root development. Soil structure is considered one of most importance to agriculture and closely related to it are other fundamental properties in soil-plant relationship. The objective of this study was to evaluate the effect of crop sequences on physical attributes. The research was realized in 2004/05 and 2005/06 growing seasons, in a Typic Clayey Rhodic Hopludox, under eight years of no-tillage system, at Dourados (MS). The experiment was a randomized complete block design, with three replications. Treatments were constituted by cover crops: sunflower ( Helianthus annuus L.), sunnhemp ( Crotalaria juncea L.), hairy vetch ( Vicia villosa Roth), mixture of sunnhemp+black oat ( Avena strigosa Schreb), and mixture of black oat+hairy vetch+oilseed radish ( Raphanus sativus L. Var. oliferus Metzg). Differences were not observed in soil density, porosity and aggregation rate when it was cultivated with sunflower, hairy vetch, sunnhemp, or the mixtures. Differences were observed in soil physical properties between 0-5 cm layer and 5-10 cm-10-20 cm layers, but no differences between 5-10 cm and 10-20 cm layers. Soil carbon trend to higher contents in crops with high production of surface residues, although differences in carbon contents were insufficient to modify aggregation.
  • Authors:
    • Pereira, D. C. de
    • Fortes, A. M. T.
    • Spiassi, A.
    • Senem, J.
    • Tomazoni, D.
  • Source: SEMINA-CIENCIAS AGRARIAS
  • Volume: 32
  • Issue: 2
  • Year: 2011
  • Summary: In agricultural crops is common planting the main crop on the remains of straw harvesting the crop earlier due to no-tillage system. The straw remaining in the soil can exert positive or negative influence on the main crop through the release of organic compounds that carry allelopathy on plants of the subsequent growing. This experiment consisted of mixing and blending of different types of turnip ( Brassica rapa L.), oats ( Avena sativa L.), crambe ( Crambe abyssinica Hochst. Ex RE Fries), Safflower ( Carthamus tinctorius L.) and rapeseed ( Brassica napus L. var) in soil and placed in plastic trays where they planted the seeds of maize. The experimental design was completely randomized design with six treatments and three repeticoes. As ratings were: emergence, rate of emergence, shoot length, root length, root dry weight, dry weight of shoots. The cover crops canola and safflower showed a positive effect, as crambe, turnips and oats had a negative effect on initial growth of maize seedlings, are not suitable for cover crop to maize sowing.