| Resumo: |
Inappropriate soil management practices that have been applied in the Yafacuy River basin, Venezuela, have led to the loss of soil organic matter and crop productivity. The incorporation of composted organic residues has been suggested as an alternative management practice in order to increase organic matter (OM) content and crop yield in these soils. The objective of this study was to determine the effects of different application fates of an organic fertilizer obtained from sugarcane industry wastes, filter cake and bagasse with or without inorganic fertilizers, on microbial biomass carbon (MB-C), soil organic carbon (SOC), maize (Zea mays L.) yield and N, P, K content in the maize leaves, in Yafacuy River basin. The experiments were established in an acid soil and an alkaline soil, both of them with low OM contents. The experimental design was a randomized complete block with seven treatments and three repetitions. It was found that the highest MB-C, SOC and maize yield were obtained with the combination of organic and inorganic fertilizers: 160 kg N ha -1 +120 kg P2O5 ha-1 + 80kg K2O ha-1 + 2000 kg ha-1 organic fertilizer. In the alkaline soil this treatment increased the MB-C and SOC with respect to the control by approximately 97 %, and 43 %, and in the acid soil by 48 % and 43 %. A linear statistically significant correlation was found between MB-C and the SOC in the alkaline soil. Maize yield and MB-C, N, P, K content in the maize leaves were found to be significantly correlated in both soils.
|
