Millet can be used as cover crop and enhance nutrient cycling in low-fertility soils. The aim of this study was to evaluate the decomposition rate and nutrient release from shoot residues of millet and sorghum left on the soil surface. The treatments consisted of pearl millet (cultivars ENA 2 and BRS 1501), and sorghum (hybrid BRS 310) plants. After cutting, at the end of the cycle, the shoot samples were placed in decomposition bags distributed on the plot surface. Plant material decomposition and nutrient release were monitored by sampling the material in the bags 10, 20, 30, 60, 90, and 120 days after cutting. The decomposition rate of biomass of millet ENA 2 was slowest (t½ (half-life) = 112 days) and higher than of BRS (98 days) and sorghum (96 days). N release by sorghum was rapid, and gradual from millet; K and the Mg were released most rapidly from all covers crops used. Results indicated that the t½ of dry matter of millet cultivar ENA 2 was highest, indicating it for tropical areas as cover plant and soil nutrient recycler, with gradual release of N, P and Ca to the soil.
plant biomass; cultivar ENA 2; soil fertility
