Abstract

The application of liquid swine manure (LSM) in the soil as biofertilizer is one of the most recycling alternatives adopted, because the nutrients contained in this residue can override, in part or totally, commercial fertilizers, crop productivity with a reduction in production costs. The goal with this work was to evaluate the use of LSM as a substitute of mineral fertilization on soybean culture in conditions of Savannah in 2014/2015. The experimental design was of randomized blocks with three replications. The treatments consisted of the use of mineral fertilizer recommended for soybean culture; without fertilization; and doses of LSM (25; 50; 75 and 100 m³ ha^-1). The levels of N, P, K, Ca, Mg, Cu, Zn, Mn and Fe in leaves, seeds and dry matter from the shoot, plant height and productivity of grain was assessed. There was no statistical difference between treatments that received mineral fertilization (P and K) and the treatments that received pig manure, indicating that the use of pig waste as bio fertilizer on soybean fertilization may be a promising alternative. The mineral fertilizer in soybean culture can be replaced by shots of LSM from 80 m³ ha^-1 with no losses in grain productivity in a clayey dystroferric Red Latosol. The applications of doses of pig manure generally did not promote increase in the content of nutrients in grains and in the extraction of nutrients by the aerial part of the soybeans plants.

Key words: Bio fertilizer, successive applications, waste, organic fertilization, animal production, organic matter.