Cultivares e épocas de corte no rendimento e composição mineral do feno de soja [Glycine max (L.) Merrill]

Abstract

The annual soybean has been detached among other leguminous plants as being rich in nutrients. Soybeans may be used to feed animals as grain, bran, roller, silage, green plant, as well as hay harvested during the vegetative, flowering, or fruit stages. With the objective of verifying the influence of the cutting periods on the yield and mineral composition of the soybean´s hay, an essay was conduced in Lavras, MG, in the agricultural year 2001/02, in a Dystrophic tipic Latosol. The experimental design used was in casualized blocks, in a factorial scheme 2 x 5, with three repetitions, containing two long life cycle soybean cultivars (Conquista and Monsoy 8400) and five cutting periods (stadium R2, R3, R4, R5 and R6). The tested soybean cultivars in this study had similar dry matter and hay yields, and higher yields were achieved when plants were harvested at R4, R5, and R6 stages. Protein content decrease when plants were harvested after R5 stage, which may be attributed to water stress and protein dilution in a high amount of dry matter. These results suggest that soybean plant for hay should be mowed at R4 stage regardless the cultivar. Monsoy 8400 cultivar presented higher total protein and K and Zn as compared to Conquista. For most of studied characteristics in this study, both cultivars, mowed for hay at more advanced vegetative stages, showed higher yields.