Produção e composição do "litter" de acessos de umbuzeiros

Abstract

Umbuzeiro, a species native to the Caatinga, is expanding as a commercial crop and requires studies for management adjustments. Nutrient cycling is essential to the sustainability of natural ecosystems and agroecosystems and translates into nutritional savings. The objective was to evaluate the productivity, contents and accumulated quantities of nutrients in the “litter” of umbuzeiro accessions of different origins. The experiment was conducted in a completely randomized design with 14 treatments, the accessions BGU-44, BGU-45, BGU-47, BRS-48, BGU-50, BGU-75, BRS-68, EPAMIG-03, EPAMIG-04, EPAMIG-05, EPAMIG-06, EPAMIG-07, EPAMIG-09 and EPAMIG-13, and three replicates composed of one plant. The yields, contents and accumulated amounts of nutrients in the “litter” vary between accessions. The decreasing order of the concentration of macronutrients in the “litter” is Ca>N>Mg>K>S>P and of micronutrients and Na, Fe>B>Mn>Na>Zn>Cu. The accumulated amounts of nutrients are more associated with the “litter” productivity of the accessions than with the concentration of nutrients. Accessions BGU-61, EPAMIG07 and EPAMIG-06 express higher litter productivity and accumulated amounts of nutrients, while EPAMIG-05, BGU-75, BGU-44, BGU-50 and BGU-45, lower ones. Data on the accumulated amounts of nutrients in the “litter” of accessions enable estimates of theoretical biogeochemical cycling and support the management of umbuzeiro as a crop, with nutritional savings.