Evaluation of methods to recovery degraded pastures of Brachiaria in the agreste region of pernambuco state. 1. Quantitative aspects

Abstract

The experiment was performed to evaluate the productive response of a degraded B. humilicola pasture to different pasture recovery methods. It was used a split-plot within a confounded randomized block design. The main plot was represented by the combination among managements and fertilization levels and the sub-plot by the deferred periods. The experimental treatments were four recovery managements (no-tillage, harrowing, harrowing + corn as a companion crop, no-tillage + corn as a companion crop), two levels of nitrogen (0 and 100 kg/ha of N), two levels of phosphorus (0 and 100 kg/ha of P2O 5) and, different periods of deferment (113, 156, 200 and 240 days), totalizing 64 treatments with three replications each one. It was found a significant interaction between recovery managements and P fertilization. The average dry matter accumulation (DMA) was 7.52: 1.68; 1.10 and 4.43 t/ha of B. humidicola for no-tillage, harrowing, harrowing + corn as a companion crop, no-tillage + corn as a companion crop, respectively. The highest deferment period increased DMA. plant heigth and B. humidicola participation in the botanical composition, as well reducing percentage of other species in the DMA and percentage of uncovered soil. Brachiaria hitmidicola pastures at the initial degradation stage, grown in low available phosphorus soils, may be recovered using a deferment period associated to a phosphorus fertilization.