19942015
  • Authors:
    • Sousa, D.
    • Rein, T.
  • Source: Better Crops with Plant Food
  • Volume: 95
  • Issue: 3
  • Year: 2011
  • Summary: The authors review recommended practices for evaluating and managing liming and fertilizer use for high yielding annual crops growing under no-till (NT) cultivation within the Cerrado.
  • Authors:
    • Carvalho, D.
    • Pereira, J.
    • Silva, L.
    • Guerra, J.
    • Souza, A.
  • Source: ACTA SCIENTIARUM-AGRONOMY
  • Volume: 33
  • Issue: 1
  • Year: 2011
  • Summary: The objective of this study was to determine the crop evapotranspiration (ETc), crop coefficients (kc) and water-use efficiency (EUA) of the bell pepper crop in the no till system (PD) and conventional tillage system (PC), in the Fluminense Valley, Rio de Janeiro State, Brazil. The irrigation was managed and the evapotranspiration demand quantified by calculating the daily soil water balance using the TDR technique and data collected in an automatic meteorological station. It was verified that the accumulated ETc at 181 days after planting (DAT) was 363 and 335 mm for PD and PC, respectively. The kcs obtained were 0.32, 1.18 and 0.77 and 0.34, 1.05 and 0.86, for the PD and PC systems, respectively, in the initial (0-40 DAP), middle (81-120 DAP) and final (181 DAP) growth phases, respectively. The kc values for the bell pepper crop presented by FAO were similar to the values found for the PC, but are not recommended for PD. Considering the total depth applied (rain and irrigation), the average values of water use efficiency were 3.9 and 4.5 kg m -3 for PD and PC, respectively.
  • Authors:
    • Sa, M.
    • Arf, O.
    • Buzetti,S.
    • Andreotti, M.
    • Teixeira Filho, M.
    • Souza, J.
  • Source: Bragantia
  • Volume: 70
  • Issue: 2
  • Year: 2011
  • Summary: The second corn crop is an important economical alternative for agriculture. As this crop removes great amounts of N, it is necessary an appropriate nitrogen fertilization management for obtaining high yields. The objective of this work was to evaluate the effect of sources, doses and times of nitrogen application on agronomic characteristics and productivity of corn grains in an irrigated second crop. The experiment was accomplished in Selviria, Mato Grosso do Sul State, in a red dystrophic Latosol irrigated by sprinkle and conducted under no till, in 2007 and 2008. The experiment was arranged in randomized complete blocks design, with 4 repetitions, disposed in a factorial scheme 5*3*2, being: five doses of N (0, 50, 100, 150 and 200 kg ha -1), three sources of N (ammonium sulfonitrate with nitrification inhibitor, ammonium sulfate and urea) applied at sowing or totally at sidedressing in the stage of 6 leaves. The N sources provided similar grain yield. The nitrogen application at sowing was viable, as well as the traditional application of N at sidedressing. The increment of N doses increased the leaf N content, the number of grains per line and per ear and consequently the grain yield. The N doses increased the grain yield of the second crop up to 150 kg ha -1 of N, independently of application time or N sources.
  • Authors:
    • Arf, O.
    • Sa, M.
    • Andreotti, M.
    • Buzetti, S.
    • Teixeira Filho, M.
  • Source: Ciencia Rural
  • Volume: 41
  • Issue: 8
  • Year: 2011
  • Summary: Proper management of nitrogen fertilization and using cultivars with high productive potential are essential to obtain high wheat yield. Thus, the objective of the present study was to assess the effects of different N doses and sources, one with a nitrification inhibitor, applied at sowing or as side dressing, on the production components and yield of two wheat cultivars irrigated, under no till, cultivated in a region of low altitude Cerrado (Selviria - MS). A randomized block design was used in a 5*3*2*2 factorial arrangement, that is, five nitrogen doses (0, 50, 100, 150 and 200 kg ha -1), three nitrogen sources (ammonium sulfonitrate with nitrification inhibitor (Entec), ammonium sulfate and urea) and two nitrogen application times (at sowing or side dressing) on two wheat cultivars ('E 22' and 'E 42') with three replications. There was no difference for grain yield between the wheat cultivars and among the nitrogen sources. The application of nitrogen totally at sowing is feasible as well as the traditional application at sowing and side dressing. The nitrogen doses increased the leaf N content of the 'E 22' cultivar, resulting in a reduction in the hectolitric mass of the 'E 42' cultivar and increased grain yield of the 'E 22' and 'E 42' wheat yield cultivars, respectively, up to doses of 126 and 122 kg ha -1 N, regardless of the application time and the nitrogen source.
  • Authors:
    • Andreotti, M.
    • Benett, C. G. S.
    • Buzetti, S.
    • Valderrama, M.
    • Teixeira Filho, M. C. M.
  • Source: Pesquisa Agropecuaria Tropical
  • Volume: 41
  • Issue: 2
  • Year: 2011
  • Summary: Coated fertilizers can provide lower losses and higher soil nutrients availability, which can be absorbed by plants, when we consider their gradual release. The objective of this study was to evaluate the effect of doses and sources of N, P, and K on maize grain components and yield, under no-till system, in the Brazilian savannah. The experimental design was randomized blocks, with 4 top-dressed doses (0 kg ha -1, 40 kg ha -1, 80 kg ha -1, and 120 kg ha -1) and 2 sources (urea and coated urea), for N; 4 doses (0 kg ha -1, 50 kg ha -1, 100 kg ha -1, and 150 kg ha -1) and 2 sources (triple superphosphate and coated triple superphosphate), for P; and 4 doses (0 kg ha -1, 40 kg ha -1, 80 kg ha -1, and 120 kg ha -1) and 2 sources (potassium chloride and coated potassium chloride), for K, with 4 replications. The fertilizers coated with polymers (urea, triple superphosphate, and potassium chloride) were not efficient under the soil and climate conditions studied, because they provided results similar to the same conventional fertilizers, for the N, P, and K foliar contents, and irrigated maize grain components and yield. The increment of N doses increased linearly the N leaf content, number of ears per hectare and maize grains yield. The application of K 2O and P 2O 5 doses did not influence grain yield.
  • Authors:
    • Mielniczuk, J.
    • Vezzani, F. M.
  • Source: REVISTA BRASILEIRA DE CIENCIA DO SOLO
  • Volume: 35
  • Issue: 1
  • Year: 2011
  • Summary: Soil functions and quality are closely linked to soil structure. The effect of management practices on the recovery of the aggregation of a physically degraded soil was studied based on the distribution of water-stable aggregates and single particles (diameter classes 9.51-4.76, 4.76-2.00, 2.00-0.25, 0.25-0.053, <0.053 mm) and carbon stock (C) in the surface layer (0-7.5 cm) of a Paleudult in the Central Depression region of the state of Rio Grande do Sul, Brazil, under different management systems. The following systems were evaluated in experimental plots after 17 years: soil without plants and without tillage (fallow); no-till Lablab purpureus and maize ( Zea mays) (Lablab/m); no-till Cajanus cajan (pea/m) and maize; perennial pasture of Digitaria decumbens (Pangola grass). The following systems were evaluated after 15 years: conventional tillage and no-till Avena strigosa and maize (CT a/m and NT a/m, respectively) Avena strigosa+ Vicia sativa and maize+ Vigna unguiculata (CT av/μ and NT av/mu, respectively). A conventionally tilled area was also evaluated after 30 years of grain cultivation (crop) and native grassland (NGr), representing the degraded state and the native ecosystem of this soil, respectively. Undisturbed soil samples collected in two seasons (September 1999 to September 2000) were evaluated in six replications per management system. Data were analyzed by ANOVA and Tukey's test (5%) to detect differences between management systems. In the NGr, 76.4% of the soil aggregates consisted of 63.8% macroaggregates and of 23.6% of single particles, and a C stock of 20.0 Mg ha -1. The agricultural use with intense soil tillage and low residue application (crop) reduced the proportion of soil aggregates to 49.9% and raised single particles to 50.1%, while the C stock decreased to 11.8 Mg ha -1. From this condition, 15 years of the untilled system with greater diversity of plant species and high residue application (NT av/mc) raised the proportion of soil aggregates to 70.7% and of macroaggregates to 53.5%. Perennial pasture (Pangola) increased the proportion of soil aggregates to 74.1% and of macroaggregates to 61.8%, equaling NGr. The systems NT av/mc, pea/m and Lablab/m recovered C stocks to the level of NGr. Although Pangola had the highest soil aggregation rates, the C stock was lower than in the said systems, emphasizing the positive action of a dense root system in the recovery of soil aggregation.
  • 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:
    • Arbugeri, F.
    • Kaminski, J.
    • Casali, C.
    • Piccin, R.
    • Doneda, A.
  • Source: Informacoes Agronomicas
  • Volume: 21-24
  • Issue: 135
  • Year: 2011
  • Summary: This study evaluated the forms of phosphorus accumulated in plant tissue cover crops and their release from the mineralization of their residues. The field work was conducted in the agricultural year 2008/2009, in the town of Mantiqueira, in the municipality of Touch-Me-Not, RS, Brazil. The treatments were: black oats ( Avena nuda), rye ( Secale cereale), pea ( Pisum sativum subsp. arvense) and radish ( Raphanus sativus var. oleferus). Observations showed that the chemical fractionation of P in plant tissue used in this study is a reliable method that aids in understanding the dynamics of the release of P. The cover crops accumulate different forms of P in plant tissue, which interferes with the dynamics of release of this element. It was also observed that rye is a plant that releases the P tissue with greater speed to the ground, while the pea tissue P releases more slowly.
  • 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:
    • Ferrari, J. V.
    • Furlani Junior, E.
    • Ferrari, S.
    • Pereira, G. A.
  • Source: SEMINA-CIENCIAS AGRARIAS
  • Volume: 32
  • Issue: 4
  • Year: 2011
  • Summary: Nitrogen application on the cover and the maintenance of straw, conducted by direct seeding, should meet the needs of agriculture and promote soil conservation. This study evaluates the effect of pre-sowing nitrogen application in cotton crops and cover crops by direct seeding, on the development and yield of cotton. It was conducted in the municipality of Selviria-MS during the agricultural years 2005/06, 2006/07 and 2007/08. The experimental design used was a randomized block design consisting of three cover crops (forage turnip, black oat and white oat) and four nitrogen doses (0, 30, 60 and 90 kg of N ha -1) in pre-sowing of cotton. In April 2006, April 2007 and April 2008, the assessments of plant development and also harvesting of the experimental plots of cotton cultivars were conducted. The results showed that after planting the cover crops, the yield and development and the heights of cotton plants increased with the use of pre-sowing N of 90 kg ha -1, also showing that the forage turnip is a coverage plant that provides increased cotton.