Avaliação agronômica da rebrota, dinâmica de decomposição e liberação de nutrientes de flemingia (Flemingia macrophylla (Willd.) Kuntze ex Merr.)

Abstract

Regrowth, dynamics of decomposition and release of nutrients by flemingia (Flemingia macrophylla (Willd.) Kuntze ex Merr.)Flemingia macrophylla is a shrubby legume of Asian origin, little explored in Brazil. The objectives of this study were the evaluation of the regrowth biomass of the species, accumulation of nitrogen in the air and evaluation of decomposition and release of nutrients from the aerial part of flemingia. Both experiments were arranged in a randomized complete block design with four replications. The regrowth biomass estimation of flemingia was performed after cutting at different heights above ground level (0.0 m; 0.3 m; 0.6 m; 1.2 m). The highest cutting height (1.2 m) maximized biomass production, at all cutting dates. Up to 34 Mg DM ha -1 were measured in nine cuttings, at 1.2 m cutting height, the equivalent to 804 kg N ha . The half-life time (T 1/2 ) of the decomposition was 91, 95 and 97 days for leaves, stems and stems + leaves, respectively. The release of N, P, Ca and Mg followed the same pattern of decomposition, however K was released in a more accelerated rate.