Absorção de nutrientes e alterações químicas em Latossolos cultivados com plantas de cobertura em rotação com soja e milho

The effects on soil chemical properties brought about by cover crops vary considerably. This study was conducted to evaluate nutrient uptake by five cover crops used for grain, seed and forage production at different seed densities per hectare, as well as uptake by spontaneous vegetation, and their effect on the chemical properties of two Oxisols when grown in rotation with soybean and corn. The experiments were set up in Votuporanga, SP, Brazil and Selvíria, MS, Brazil in March 2008 after conventional soil tillage. A randomized complete block experimental design was used with four replications with the following cover crops at different seed densities: Sorghum bicolor at 6, 7 and 8 kg ha-1; Pennisetum americanum at 10, 15 and 20 kg ha-1; Sorghum sudanense at 12, 15 and 18 kg ha-1; hybrid of Sorghum bicolor with Sorghum sudanense at 8, 9 and 10 kg ha-1; and Urochloa ruziziensis at 8, 12 and 16 kg ha-1. We also used a spontaneous vegetation control. After management of the cover crops, in the first year of study, soybean was sown in no-tillage system and, in the second year, corn was sown, also in a no-tillage system. We evaluated the dry matter yield of different cover crops, nutrient uptake by the cover crops, and the chemical changes in the soil. It was found that in clayey soils with high aluminum content, as in Selvíria, sudan grass at a seed density of 18 kg ha-1, and sorghum at a seed density of 6 kg ha-1, in combination with liming, contributed to reduction of aluminum content and high potential acidity and an increase in base saturation. The different seed densities of each cover crop did not affect the dry matter yield of the cover crop itself, but affected nitrogen uptake of the hybrid Sorghum bicolor with Sorghum sudanense at a seed density of 10 kg ha-1, with lower uptake than at a seed density of 8 kg ha-1. Seed density also affected the organic matter content in the soil with sudan grass, with the seed density of 15 kg ha-1 providing more organic matter content than a seed density of 18 kg ha-1.

Nutritional balance and yield for green manure orange trees

Intercropping could efficiently prevent soil nutrient losses caused by extensive agriculture. The present study aimed to assess the effect of green manure on the nutritional status of orange trees cultivar 'Pera' (Citrus sinensis (L.) Osbeck). The plants were grafted on 'Cravo' lime trees and were then planted in a 7x4m space. Four different treatments corresponding to the evaluated green manures were employed: jack bean (JB) (Canavalia ensiformis DC), lablab (LL) (Dolichos lablab L.), pigeon pea (PP) (Cajanus cajan L. Millsp), and Brachiaria (BQ) (Brachiaria brizantha Hochst ex A. Rich. Stapf) as control. The experimental design was in randomized blocks, in split-plot time, with six replicates, with four treatments (green manures) and two plants per evaluation. The nutritional status was assessed by using the DRIS method (Diagnosis and Recommendation Integrated System); the yield and the macro and micronutrient levels contained in green manures and in the control was also determined. The nutritional diagnosis indicated that, in the two years of experiment, plants treated with green manure showed better nutritional balance index compared to Brachiaria. This suggests that, over time, green manure can lead to better nutritional balance. Pigeon pea treatment showed the highest yields, compared to control, in the two evaluated crop cycles (2004/05 and 2005/06).

Desempenho técnico e econômico da produção de milho e sorgo para silagem e soja em sucessão em sistema irrigado de integração lavoura-pecuária no cerrado

Pós-graduação em Agronomia - FEIS

Acúmulo de macronutrientes e decomposição da palhada de braquiárias em razão da adubação nitrogenada durante e após o consórcio com a cultura do milho

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito da época e sistema de semeadura da Brachiaria brizantha em consórcio com o milho, sobre os componentes de produção e propriedades físicas do solo

The objective of this study was to evaluate the development of Brachiaria brizantha- MG-4; sown in two seasons and two seeding systems in space between two rows, and to evaluate the effect of intercropping on maize yield, as well as evaluating the physical properties of the soil after the consortium. The experiment was conducted in the agricultural year 2010, the Municipality of Quatro Pontes/PR. The experimental design was randomized blocks as a factorial 2x2, and an additional treatment that was corn cultivation single, with four replications. The treatments consisted two intercropping systems: corn intercropped with Brachiaria brizantha in the row, and corn intercropped with Brachiaria brizantha in space between two rows, and two times of sowing Brachiaria brizantha: simultaneously corn, and twenty-five days after sowing corn. The seed was planted mechanically in no-tillage system, with spacing between the lines of 0,70 m. The ears were harvested by hand and in the laboratory were evaluated: yield components and productivity. Brachiaria brizantha- MG-4 was sown and harvested manually. We evaluated the production of fresh and dry mass and yield components. For soil analyzes the soil was sampled at 0-0.10 and 0,10-0,20 m. Were determined the total porosity, macroporosity and microporosity. The results demonstrated that the production components of Brachiaria brizantha were lower when it was sown twenty-five days after sowing corn, and between sowing systems when Brachiaria brizantha was sown in line. There was no reduction in grain yield of maize intercropped with Brachiaria system independent and sowing date. The consortium of pasture with corn increased the total porosity, and reduced soil bulk density.

Effect of dietary energy concentration on performance parameters and egg quality of white leghorn laying hens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desempenho, qualidade de carcaça e da carne de cordeiros alimentados com dietas contendo silagens de milho consorciadas ou não com capins tropicais

Pós-graduação em Ciência e Tecnologia Animal - FEIS

Produção de soja e milho cultivados sobre diferentes coberturas

The no-tillage system is an important technique for maintaining and restoring the productive capacity of conventionally managed soils and degraded areas. The aim of this study was to evaluate the production of soy and maize grown on the straw of five cover crops and on spontaneous vegetation. The experiments were carried out in Votuporanga, in the state of Sao Paulo and in Selviria, in Mato Grosso do Sul, Brazil, in March 2008, after conventional soil preparation. The experimental design was of randomised blocks with four replications, using the following cover crops in different amounts of seed per hectare, to make up the treatments: Sorghum bicolor - 6, 7 and 8 kg ha(-1); Pennisetum americanum - 10, 15 and 20 kg ha(-1); Sorghum sudanense - 12, 15 and 18 kg ha(-1); S. bicolor and S. sudanense hybrid - 8, 9 and 10 kg ha(-1); and Urochloa ruziziensis - 8, 12 and 16 kg ha(-1). A control treatment with spontaneous vegetation was also used. After management of the cover crops, soy was planted in the first year of the study, and maize sown in the second, both under a no-tillage system. The dry matter accumulated by the different cover crops, and the agronomic characteristics of the soy and maize were all evaluated. It was concluded that the different cover plants proved to be good options for preceding the soy crop in Votuporanga, SP and the maize in Selviria, MS, and that the different amounts of seed used for each cover crop resulted in differences in relation to the agronomic characteristics of the crops of soy and maize.

Energy values of traditional ingredients and sugarcane yeast for laying hens

An experiment was conducted to determine the chemical composition and apparent metabolizable energy (AME) and apparent metabolizable energy corrected for nitrogen balance (AMEn) values of corn, soybean meal (SBM), soybean oil (SO) and sugarcane yeast (SY) (Saccharomyces cerevisiae). A metabolism trial was performed with 120 Dekalb White laying hens at 65 weeks of age, using the method of total excreta collection. Birds were housed in metabolism cages and distributed according to a completely randomized design into five treatments with, six replicates of four birds each. The experimental period consisted of four days of adaptation and four days of excreta collection. The experimental diets included: a reference diet based on corn and SBM and four test diets containing 40% corn, 30% SBM, 10% SO or 30 % SY. The chemical compositions of the tested ingredients, expressed on "as-is" basis were: 86.9, 87.29, 87.32 and 99.5% dry matter; and 3.51, 2.08, 99.31 and 0.03 ether extract for corn, SBM, SO and SY, respectively. Corn, SBM, and SO presented 7.33, 43.61 and 24.64% crude protein, and 0.58, 5.07 and 6.77% ash, respectively; and crude fiber contents of corn and SBM were, respectively, 2.24% and 3.56%. The following AME and AMEn (kcal/kg dry matter) values were obtained: 3,801 and 3,760 kcal/kg for corn, 2,640 and 2,557 kcal/kg for SBM, 8,952 and 8,866 kcal/kg for SO, and 1,023 and 925 kcal/kg for sugarcane yeast, respectively.

Sistemas de cultivo antecessores e doses de nitrogênio em cobertura no feijoeiro em plantio direto = cover crop systems and nitrogen topdressing on common bean in no tillage

The objective of this work was to evaluate the grass cover crop production in crop systems involving maize and Urochloa ruziziensis, and the influence of topdressing nitrogen rates in the yield and agronomic efficiency on common-bean cultivated in succession in no-tillage. The experiments were conducted in Jaboticabal-SP, in a eutrophic red latosol, in the second year of no-tillage system implementation. The IPR 139 cultivar was used in split plot design with three replications, in randomized block. The plots had been composed for three crop systems in the summer season, with maize exclusive, maize intercropped with U. ruziziensis and U. ruziziensis exclusive. The subplots had been constituted for five nitrogen rates (0, 40, 80, 120 and 160 kg ha(-1)), applied as topdressing at V4-4 in irrigated common-bean cultivated in the winter-spring season. The use of U. ruziziensis in crops systems, exclusive or intercropped with maize favors the grass cover crop production sufficiently to total soli surface covered, possibility similar grain yield compared to maize exclusive. The topdressing nitrogen application doesn't affect the common-bean yield in succession to maize and U. ruziziensis intercropped. The increase of nitrogen rates in common-bean in succession to maize exclusive improves the yield, although decreases the agronomic efficiency.

Silagens de milho consorciado com forrageira tropical e leguminosa em dietas para terminação de cordeiros

Pós-graduação em Ciência e Tecnologia Animal - FEIS

Estabelecimento do capim-massai em consórcio com milho AG-1051 e Bt, em áreas infestadas pelo percevejo castanho das raízes.

The system consortium of grain crops with forage plants allows the establishment of pastures resistant, vigorous and lower cost in areas infested with stink bug brown root. Maize has favorable characteristics for intercropping as high plant height and insertion height of the studs, allowing the crop to occur without interference of forage plants. Furthermore, the production system in consortium with Bt corn reduced the infestation of Spodoptera frugiperda and was not affected by Scaptocoris carvalhoi (Hemiptera: Cydnidae), The Panicum maximum cv. Massai allowed a consortium with excellent corn and pasture provided a vigorous and excellent leaf mass distribution and very deep roots in the soil. Grain yield for Bt corn was higher and significant (P <0.05), compared to other treatments. The use of Lorsban (1.5 liters / ha) and Thiodan (2.0 liters / ha) was highly effective (P <0.05) in the control of Spodoptera frugiperda and Scaptocoris carvalhoi (Hemiptera: Cydnidae).

Custos energéticos do agroecossistema pinhão-manso e milho: comparativo entre o sistema de condução sequeiro e o irrigado

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Intake, nutrient apparent digestibility and ruminal constituents of sheep fed diets with canola, sunflower or castor oils

The objective in this experiment was to determine the effects of feeding diets with canola, sunflower or castor oils on intake, nutrient apparent digestibility and ruminal constituents of crossbred Dorper x Santa Ines sheep. Four rumen-cannulated animals of 90.2 +/- 11.4 kg average body weight were assigned to a 4 x 4 latin square. Animals remained individually in cages for the metabolism assay and were fed diets containing roughage at 500 g/kg and concentrate based on ground corn and soybean meal also at 500 g/kg. No oil was added to the control diet, whereas the others had canola, sunflower or castor oils at 30 g/kg (DM basis). There was no difference for the intake of DM and nutrients, except for ether extract, which was greater when animals received oil. The digestibility coefficients of dry matter, organic matter, crude protein, non-fiber carbohydrates and neutral detergent fiber were not changed; however, the addition of oil increased the ether extract digestibility. The values of total digestible nutrients (TDN, g/kg of DM), digestible energy (DE, Mcal/kg of DM), TDN intake and DE intake also did not change with the addition of lipids. Concerning the ruminal constituents, the addition of vegetable oils reduced the concentrations of acetate, butyrate and total short-chain fatty acids. Adding canola, sunflower or castor oils at 30 g/kg in diets with 500 g roughage/kg and 500 g concentrate/kg does not impair the intake or digestibility of nutrients in sheep, although it reduces the concentration of short-chain fatty acids in the rumen.

Substituting Wet Distillers Grains or Condensed Distillers Solubles for Corn Grain in Finishing Diets for Yearling Heifers

A feeding trial was conducted with 790-lb yearling heifers fed an average of 121 days to evaluate replacing cracked corn and supplemental urea with wet distillers grains or condensed distillers solubles. Wet distillers grains were evaluated at 16%, 28% and 40% of diet dry matter. Condensed distillers solubles were added at 6.5% of diet dry matter. Control diets were supplemented with urea or a combination of urea and soybean meal. Feeding 16% wet distillers grains or condensed distillers solubles increased gain of heifers compared with those fed the control urea diet. Increasing the amount of wet distillers grains tended to decrease feed intake and reduce gain. The calculated apparent net energy based on gain of the heifers was greatest for the heifers fed 16% wet distillers grains. The apparent energy of the wet distillers grains declined as the quantity fed was increased. The calculated net energy values were 1.09 and 1.35 Mcal/lb of dry matter for the average of the three concentrations of wet distillers grains and condensed distillers solubles. These results confirm the high energy values of wet distillers grains relative to cracked corn as observed in a previous steer feeding trial.