Row spacing for pigeon pea sowing and its influence on the recovery of degraded pasture

Abstract

The objective of this work was to evaluate the effect of row spacing for sowing of ‘BRS Mandarim’ pigeon pea (Cajanus cajan) on soil fertility and on the yield and nutritional values of brachiaria (Urochloa decumbens) pasture. Pigeon pea was sown in an area in the initial stage of degradation and cultivated with brachiaria. Four row-spacing treatments were evaluated for pigeon pea sowing, using the following row spacing: single rows spaced at 40, 80, and 120 cm; and a double-row with 40 cm between rows, spaced at 120 cm. In addition, a reference area treatment without pigeon pea was used. The nutritive parameters of the total available forage and of the pigeon pea plants were measured at three following development stages of pigeon pea plants: vegetative stage, at 79 days after sowing (DAS); beginning of the reproductive stage, with green pods, at 157 DAS; and final stage of grain production (dry pods), at 281 DAS. The use of the legume provided an economy of up to R$ 1,716.30 ha−1 in the application of nitrogen fertilizers. Pigeon pea used as green manure provides a significant increase of 53.5 to 140% in the dry matter yield of brachiaria.