With the objective of evaluating the effect of the application of fresh, digested and codigested pig slurry, two biological experiments with maize were carried out in Kick- Brauchmann pots, using a Cambic Arenosol. An organic–mineral fertilizer obtained by the application of Pulse technology, and partially sintethised with pig slurry, amongst other residues, was also tested. All the materials were used separately, to supply the following amounts of N to the crop: 0, 75, 100 and 125 kg N/ha. Plant growth, nitrogen uptake and nitrogen content of soil after the experiments were evaluated. Nitrate and phospsorus leaching losses from the pots as well as organic matter fractionation were determined at the end of both experiments. Pig slurries in general, were the treatments that allowed higher productions, higher N uptake and lower N losses. Digested slurry was responsible for the greater P losses by leaching. Treatments where pulse fertilizers were applied led to the higher accumulation of N in the soil.

Mestrado em Engenharia do Ambiente - Tecnologias Ambientais - Instituto Superior de Agronomia