Cama de frango, esterco de curral e pó de carvão no estado nutricional da soja

Abstract

Foliar nutrient levels are important indicators of nutritional status of soybean plants. In this sense, the objective of this paper was to evaluate the effects of different organic wastes on growth and nutritional status of soybean plants. A field experiment was carried out in a Cambissol under conventional soil tillage, evaluating three organic sources (poultry litter, farmyard manure and biochar) (plots) at rates of 0, 3, 6 and 9 Mg ha-1 (split plots) combined with 0, 100, 200, 300 and 400 kg ha-1 (split split-plots) of the mineral fertilizer, in 2008. All nutrients were affected by treatments, except the levels of Cu and B. The input of organic wastes increased the nitrogen levels in soybean plants. The poultry litter provided the highest phosphorus levels in the plants. It was found poultry litter caused the largest increases of P, K, Mg and S nutrients levels. The poultry litter and farmyard manure, associated to mineral fertilizer, boosted the foliar area index. All nutrients, except the S, correlated positively and linearly to the grain yield. The use of organic waste is an interesting strategy aimed at improving the nutritional status of soybean by boosting the foliar levels of N, P, K, Mg, S and Fe.