Acúmulo de matéria seca e marcha de absorção de nutrientes em soja de crescimento determinado e indeterminado

Abstract

Absorption and distribution of nutrients in plants are essential for proper growth of various vegetal organs, branching, leafing, and development of pods and grains. The goal of this study was to determine the dry matter yield and nutrient accumulation in the shoot of soybean cultivars of determined and undetermined growth. The experiment was carried out in an experimental farm of the Agricultural Sciences sector, Federal University of Grande Dourados (UFGD), in the city of Dourados - MS (Brazil). It was conducted during the 2016/2017 growing season, using cultivars BRS 317 (determined growth) and BRS 1001 IPRO (undetermined growth). The experimental design was a randomized block, the factors consisted of two soybean cultivars (BRS 317 and BRS 1001 IPRO) and seven sampling times (15, 30, 45, 60, 75, 90, and 105 days after plant emergence). Each experimental unit contained six 20- m rows spaced 0.45 m apart, and sowing density to obtain 13 seedlings per meter. Plant shoot samples were taken from 10 plants per rampling time. Each sample was split into leaf (limbus and petiole), stem, branch, pods, and grains, and then weighed and subjected to analysis of macronutrients. the extraction order of macronutrients in the cultivars BRS 317 and BRS 1001 were : N > K > Ca > P > Mg > S. The cultivar BRS 1001 presented bigger accumulation of Mg in the leaves, K and Ca in the grains and Mg in the pods related to the cultivar BRS 317. The accumulation of S follows the following order: for the cultivar of determined growth BRS 317 grains > branch > leaf > pod > stem, while the cultivar of indeterminate growth presented the following order: grains > branch > pod > stem > leaf.