Decomposi？？o e ciclagem de nutrientes dos resíduos de quatro plantas de cobertura do solo

pearl millet and sorghum can be used as cover plants for soil and recycling of nutrients in soils of low fertility. this study evaluated the nutrient cycling and decomposition of crop residues of four cover crops in sandy soil, without fertilizer or irrigation. the treatments consisted of two pearl millet genotypes (cultivar ena 2 and brs1501), sorghum genotype brs 310 and non- cultivated plants (weeds - ve). samples of shoots, stratified into leaves and stems collected 87 days after planting were placed in bags and distributed on the surface of the plots. the dry matter decomposition and nutrient release were monitored through collection of material from the bags 10, 20, 30, 60, 90 and 120 days after cutting. the ena 2 showed the greatest amounts of biomass and dry weight of stems and higher levels of n, p and k in its remaining detritus, followed by sorghum, brs 1501 and ve. with the exception of k, there was a rapid release of all nutrients by ve, while the ena 2 nutrient release was more gradual, and was intermediate and similar for brs 1501 and sorghum. the greater dry weight and slower decomposition of cultivar ena 2 make it the recommended genotype for use as soil cover and nutrient recycling.