Adubos verdes na produção de alface e cenoura, sob sistema orgânico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Qualidade física em um latossolo vermelho sob sistema de semeadura direta

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Plantas de cobertura e época de semeadura na produtividade e qualidade fisiológica de sementes de cultivares de feijão em sistema de plantio direto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Culturas de cobertura, doses de nitrogênio e residual da aplicação de calcário: características químicas do solo, estado nutricional e características agronômicas do milho

Pós-graduação em Agronomia - FEIS

Matéria orgânica do solo em rotações de culturas sob sistema semeadura direta

Pós-graduação em Agronomia (Agricultura) - FCA

Coberturas vegetais e doses de nitrogênio em trigo sob sistema plantio direto

The application of conservation practices in production systems is essential to the sustainability of the agricultural production capacity. The use of different cover crops can reduce the need of topdressing nitrogen fertilizers in wheat crops. This study aimed at evaluating the influence of cover crops residues (millet, sunn hemp, pigeon pea, millet + sunn hemp, millet + pigeon pea and fallow ground), grown previously to the summer crop (rice), and topdressing nitrogen doses (0 kg ha-1, 25 kg ha-1, 50 kg ha-1, 75 kg ha-1, 100 kg ha-1 and 125 kg ha-1), in the development and yield of wheat under no-tillage system. The experiment was carried out in Selvíria, Mato Grosso do Sul State, Brazil, in a Red Oxisol, in 2009/2010 and 2010/2011. The experimental design was randomized blocks, in a 6x6 factorial scheme. The cover crops developed during August/October (2009/2010) and September/November (2010/2011), previously to the summer crop, with the chemical desiccation performed respectively at 73 and 55 days after sowing. The wheat (winter) was sown in May, in both periods, and harvested at 113 (2009/2010) and 106 (2010/2011) days after emergence. The cover crops residues of pigeon pea, sunn hemp and millet + sunn hemp, preceding wheat, provided higher wheat yields, relatively to the fallow ground. The wheat yield showed a quadratic response to the increase in the nitrogen availability, reaching higher yields with the nitrogen doses estimated in 113 kg ha-1 (2010) and 98 kg ha-1 (2011).

Produtividade do milho em condições de diferentes manejos do solo e de doses de nitrogênio

Research has been conducted to identify the best nitrogen (N) rate for maize in most diverse types of soil management. However, there is no agreement on the results, once the dynamic of N is influenced by soil management and cover crops. This study evaluated dry mass production and nutrient uptake by cover crops, agronomic parameters and grain yield of maize in response to soil management and N rates. Field trials were carried out in Selvíria, Mato Grosso do Sul State, Brazil, in the growing seasons of 2009/2010 and 2010/2011, on a clayey Rhodic Haplustox (20º 20' S and 51º 24' W, 340 m asl). Thirty-six treatments were established with four replications, in a randomized blocks design, with the combination of cover crops (millet, Crotalaria juncea and millet + Crotalaria juncea), soil management systems (tillage with chisel plow + lightweight disking, heavy disking + lightweight disking, and no-tillage) and topdressing N rates (0, 60, 90 e 120 kg ha-1 - urea as source). Maize hybrid DKB 350 YG® was used and N applied at stage V5 (fifth expanded leaf). A linear increase with the increase of N rates was observed for chlorophyll leaf index, leaf N content, ear length and diameter, and grain weight and yield. Previously grown sunn hemp and millet + sunn hemp grown, associated with 120 kg ha-1 N for maize, induced a higher grain yield after two growing seasons.

Coberturas vegetais, manejo do solo, doses de nitrogênio e seus efeitos na nutrição mineral e nos atributos agronômicos do milho

Research has investigated the best nitrogen rate for maize under the most diverse types of soil management. The aim of this study was to evaluate the influence of cover crops, soil management and topdressed N rates on the dry matter production, nutritional status, plant lodging, plant height and first-ear insertion of maize. Field experiments were carried out in Selvíria, Mato Grosso do Sul State, Brazil, in the growing seasons of 2009/2010 and 2010/2011, on a clayey Rhodic Haplustox (20º 20' S and 51º 24' W, at 340 m asl). Thirty-six treatments were established with four replications, in a randomized blocks design, to test combinations of cover crops (millet, Crotalaria juncea and millet + Crotalaria juncea), soil management (tillage with chisel plow + lightweight disking, heavy disking + lightweight disking, and no-tillage system) and N rates (0, 60, 90 e 120 kg ha-1 - urea as source). The maize hybrid DKB 350 YG® was used and topdressing N applied at stage V5 (fifth expanded leaf). Previously grown sunn hemp and millet + sunn hemp resulted in a higher shoot dry matter, P leaf content and total N, P and K uptake. In the no-tillage system, the initial and final population and shoot dry were highest, and first-ear insertion and plant height lower. The application of 120 kg ha-1 topdressed N increased the P leaf content, N and P in the entire plant, shoot dry matter, total N, P and K uptake, plant height, and the first-ear insertion of maize.

Purification and biochemical characterization of an alkaline pectin lyase from Fusarium decemcellulare MTCC 2079 suitable for Crotolaria juncea fiber retting

An extracellular pectin lyase secreted by Fusarium decemcellulare MTCC 2079 under solid state fermentation condition has been purified to electrophoretic homogeniety by using ammonium sulfate fractionation, carboxymethyl cellulose and gel filtration (Sephadex G-100) column chromatographies. The purified enzyme showed single protein band corresponding to molecular mass 45 +/- 01 kDa on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme had maximum activity at pH 9.0 and showed maximum stability in the pH range of 9.0-12.0. The optimum temperature of the purified enzyme was 50 degrees C and it showed maximum stability upto 40 degrees C. The energy of activation for the thermal denaturation (Ea) was 59.06 kJ mol(-1) K-1. The K-m and k(cat) values using citrus pectin as the substrate were 0.125mgml(-1) and 72.9 s(-1) in 100mM sodium carbonate buffer pH 9.0 at 50 degrees C. The biophysical studies on pectin lyase showed that its secondary structure belongs to alpha+beta class of protein with comparatively less of beta-sheets. Purified pectin lyase showed efficient retting of Crotolaria juncea fibers.

Dinâmica do nitrogênio em sistemas de produção sob semeadura direta

Pós-graduação em Agronomia (Agricultura) - FCA

Análise econômica do milho em sucessão a diferentes adubos verdes, manejos do solo e doses de nitrogênio

Technologies that increase crop yields are possible when providing profitability to the producer. The objective of this study was to evaluate production costs and profitability of maize in production systems in Cerrado. The study was conducted in Selviria (Mato Grosso do Sul State), Brazil, in the years 2009/10 and 2010/11. The experiment was arranged in randomized blocks with four replications in factorial and mixed with tracks. We established 36 treatments, three green manures (Pennisetum glaucum, Crotalaria juncea and intercropping Pennisetum glaucum + Crotalaria juncea), three soil management practices (no-tillage system, "heavy disking" + "levelling disking" and "chisel plow" + "levelling disking") and four doses of N (0, 60, 90 and 120 kg ha(-1)). For economic analysis were estimated operational cost, the gross revenue obtained by the product of the productivity of the treatments and the value of corn (R$ 0,417 kg or R$ 25,00 sc(-1)) and the ratio revenue / cost of treatment. Whereas higher values (revenue/cost > 1) and lower (revenue/cost ratio < 1) as a parameter in the analysis of profitability, it can be concluded that corn under no-tillage had the highest profitability in succession to Pennisetum glaucum growing profitability with increasing N rates, in succession to Crotalaria juncea and in the absence of nitrogen application on the coverage achieved higher profitability compared to other treatments and in succession to the consortium Pennisetum glaucum + Crotalaria juncea doses of N was between 50 and 55 kg ha(-1) offer greater profitability to the cultivation of corn.

Effect of cropping systems in no-till farming on the quality of a Brazilian Oxisol

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Formas orgânicas e inorgânicas de fósforo no solo em função de plantas de cobertura e de adubação nitrogenada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ciclagem do nitrogênio relacionada ao sistema de produção

Pós-graduação em Agronomia (Agricultura) - FCA

Phosphorus utilization by corn as affected by green manure, nitrogen and phosphorus fertilizers

The objective of this work was to evaluate the utilization by corn plants of P from triple superphosphate fertilizer labeled with P-32 (P-32-TSP), and of P from soil as affected by N rates and by the green manures (GM) sunn hemp (Crotalaria juncea) and millet (Pennisetum glaucum). The experiment was carried out using pots filled with 5 kg Oxisol (Rhodic Hapludox). A completely randomized design was used, in a 4x4x2 factorial arrangement, with four replicates. The treatments were: four P rates as TSP (0, 0.175, 0.350, and 0.700 g P per pot); four N rates as urea (0, 0.75, 1.50, and 2.25 g N per pot); and sunn hemp or millet as green manure. The additions of N and P by the GM were taken into account. After grain physiologic maturation, corn dry matter, P contents, accumulated P, and P recovery in the different treatments were measured. P-32-TSP recovery by corn increased with N increasing rates, and decreased with increasing rates of P-32-TSP. The mineral fertilizer provides most of the accumulated P by corn plants. The recovery of P-32-TSP by corn was 13.12% in average. The green manure species influence the assimilation of P-32-TSP by the plants.