Calagem, adubação e nutrição mineral de Anonáceas

Among the edaphic factors, those related to acidity are the ones that affect productivity, especially in tropical regions. For culture the Annonaceae, no research results that indicate the proper base saturation, nor the determination of doses, times, application methods and sources of nutrients for orchards Annonaceae in training and production in order to promote sustainability and higher yields. Given the importance and potential of commercial exploitation of Annonaceae in Brazil and, considering the limited available scientific information on liming, fertilization and nutrition of fruit plants of this family, some research has to be carried out urgently due to the effects of nutrients on productivity, fruit quality, post-harvest, tolerance to pests and diseases, etc.

Determination of reactivity rates of silicate particle-size fractions

The efficiency of sources used for soil acidity correction depends on reactivity rate (RR) and neutralization power (NP), indicated by effective calcium carbonate (ECC). Few studies establish relative efficiency of reactivity (RER) for silicate particle-size fractions, therefore, the RER applied for lime are used. This study aimed to evaluate the reactivity of silicate materials affected by particle size throughout incubation periods in comparison to lime, and to calculate the RER for silicate particle-size fractions. Six correction sources were evaluated: three slags from distinct origins, dolomitic and calcitic lime separated into four particle-size fractions (2, 0.84, 0.30 and <0.30-mm sieves), and wollastonite, as an additional treatment. The treatments were applied to three soils with different texture classes. The dose of neutralizing material (calcium and magnesium oxides) was applied at equal quantities, and the only variation was the particle-size material. After a 90-day incubation period, the RER was calculated for each particle-size fraction, as well as the RR and ECC of each source. The neutralization of soil acidity of the same particle-size fraction for different sources showed distinct solubility and a distinct reaction between silicates and lime. The RER for slag were higher than the limits established by Brazilian legislation, indicating that the method used for limes should not be used for the slags studied here.

Doses de lodo de esgoto compostado em produção de tapete de grama esmeralda imperial

The efficiency of nitrogen fertilization for sod production can be increased by using slow-release sources such as sewage sludge compost, which, due to its characteristics can be a substitute of part or all inorganic fertilization for grass. No results were found for the use of sludge compost in sod production in Brazil. This study evaluated the effect of rates of sewage sludge compost on the production of zoysiagrass. Treatments consisted of five rates of composted sewage sludge compost (0, 12, 24, 36 and 48 Mg ha-1, on a dry basis), plus a treatment of inorganic fertilization (300 kg ha-1 N, 80 kg ha-1 P2O5, and 200 kg ha-1 K2O). The results indicated different mineralization rates of the organic compounds present in the sludge; 120 days after sludge application, more Mg (100 %), K (90 %) and N (67 %) has been released than S (57 %), P (40 %) and Ca (31 %). The use of composted sewage sludge for zoysiagrass adequately supplied nutrients when applied to the soil surface at rates more than 36 Mg ha-1. After sod cutting, the rates of sewage sludge compost provided a linear increase in potential soil acidity, soil contents of OM, P, S, Fe, Cu, Mn, Zn, Cu and Ni, and linear decrease in pH, soil concentration of Ca and Mg and base saturation. Compost rates, increasing from 0 to 48 Mg ha-1, reduced the sod mass, reaching values of 4.0 kg/sod at the highest rate. High compost doses (36 and 48 Mg ha-1, respectively) also induced the highest resistance, with values in the order of 35 and 33 kgf.

Aplicação de corretivos de acidez do solo na implantação do sistema plantio direto

Pós-graduação em Agronomia (Agricultura) - FCA

Culturas de cobertura, residual de nitrogênio e reaplicação de calcário em sistema plantio direto: cultura da soja

Pós-graduação em Agronomia - FEIS

Manejo do lodo de esgoto e nitrogênio mineral na fertilidade do solo ao longo do tempo

The use of sewage sludge is a practice highly promising for the development of sustainable agricultural systems. The objective of this study was to assess the improvement in soil fertility management strategies on different sewage sludge and mineral nitrogen after seven application of this residue. The experiment was carried at the Sao Manuel Experimental Farm belonging to the faculty of Agronomic Sciences of UNESP, Botucatu, located in the county of Sao Manuel. It was adopted the experimental design in a randomized blocks consisting of six treatments and five repetitions defined as follows: T0 - without nitrogen fertilizer, T1 - mineral fertilizer nitrogen according to the crop needs, T2 - 50% nitrogen from sewage sludge and 50% in the form of chemical fertilizer, T3 - 100% of nitrogen recommended by the culture, from sewage sludge, T4 - 150% of nitrogen recommended by the culture, from sewage sludge and T5 - 200% of the nitrogen from the sewage sludge. It has done seven application of sewage sludge in crop ( year 1 - sunflower, year 2 sunflower, year 3 - oats and bean, year 4 - triticale and sunflower, year 5 - wheat) and the first three applications were treated with sewage sludge and the other applications were composted sludge. In the depth 0-20 cm, the sewage sludge promoted an increase in levels of organic matter, P, S, H+Al, CEC and decreased in soil pH. In the depth of 20 to 40 cm the sewage sludge promoted a decrease in pH and increase in soil organic matter, P, H+Al, K, Ca, SB, CEC and S. Mineral N influence the increase in the depth S of 20-40 cm.

Acidez do solo afetando concentração de micronutrientes, atividade da enzima nitrato redutase e produtividade em plantas de arroz de terras altas

The lowest grain yield of rice under no-tillage system (NTS) in relation to the conventional system may be due to the predominance nitrate in the soil and the low nitrate reductase activity. Another reason may be caused by micronutrient deficiency because of superficially soil acidity corrections. Therefore, the objective of this study was to evaluate the changes caused by soil pH in the N forms in the soil, micronutrients concentration in rice plants, nitrate reductase activity, yield of rice and its components. The experiment was performed in a greenhouse conditions. The experimental design was a completely randomized in a factorial three (levels of soil acidity) x five (micronutrients sources) with four replications. The addition of micronutrients does not affect levels of nitrate and ammonium in the soil; soil acidity significantly affects levels of nitrate and ammonium in the soil, concentration of micronutrients in rice plants and crop yield and its components; medium soil acidity (pH 5.5) result in medium to high levels of Cu and Fe, medium level of Zn and Mn, high nitrate reductase activity, resulting in higher dry matter, tillers, panicles, spikelets, weight of 100 grains and hence grain yield.

Efeito do composto de lixo urbano em um solo arenoso e em plantas de sorgo

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

Resposta da cana-de-açúcar à aplicação da escória de siderurgia como corretivo de acidez do solo

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

Eficiência agronômica de rejeitos da indústria de fertilizantes fosfatados

Pós-graduação em Agronomia (Horticultura) - FCA

Disponibilidade de fósforo em solo tratado com resíduos urbanos e industriais sob sistema de plantio direto cultivado com soja

Pós-graduação em Agronomia (Agricultura) - FCA

Potencial de uso agrícola de levedura seca inativa de cana-de-açúcar e de resíduos orgânicos

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Efeitos de plantas de cobertura em atributos químicos do solo

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Effects of surface application of dolomitic limestone and calcium-magnesium silicate on soybean and maize in rotation with green manure in a tropical region

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

Calagem superficial e aplicação de gesso em sistema plantio direto de longa duração: efeitos no solo e na sucessão milho/crambe/feijão-caupi

Pós-graduação em Agronomia (Agricultura) - FCA