Study of biological activity in northeast Brazil's coastal tableland soils treated with organic residue: stillage and sugar cane solid residue

摘要

Epipedons of two representative soils from "Coastal table lands" of Northeastern Brazil cultivated with sugar cane were selected for the study. These soils were fertilized with 10 (T1), 20 (T2) and 30 (T3) t ha-1 of solid sugar cane residue (C/N=19.33) and 30 (V1), 60 (V2) and 90 (V3) m3 ha-1 of stillage (C/N=32,17). The fertilizers were incorporated without previous composting. After incorporation, samples were incubated under controlled conditions of temperature and humidity in laboratory according to Gucker's method for 39 days. The soil samples received lime treatment (2 t ha-1 CaCO3) 27 days after fertilizer application. In both soils, treatment T3 did not significantly differ from control before and after liming. Greater biological activity was observed under 10 and 20 t ha-1 of sugar cane solid residue treatment. In both soils, 90 m3 ha-1 of stillage induced minimum biological activity, very close to control response. In no case was inhibition of biological activity due to treatment observed. After incubation, some soil parameters were characterized to associate sugar cane organic fertilizers with soil fertility.