Productivity of Brachiaria decumbens as a function of the preceding crop and nitrogen and phosphorus fertilization

Abstract

The objective of this project was to study the effects of the preceding crop and N ( 0 and 40 kg ha-) and P (0, 20, and 40 kg ha-) fertilization on the yield and quality of seeds as well as the production of forage of Brachiaria decumbens. The experiment was carried out in Selviria, Mato Grosso do Sul, Brazil. Millet, grain sorghum, dwarf pigeon pea, forage turnip, and a fallow area were the species and the situation preceding the sowing of B. decumbens. Dwarf pigeon pea, forage turnip, and grain sorghum had the plants dry matter content, macronutrients contents, and grain production evaluated. Millet had not its grain production evaluated. The evaluations performed for B. decumbens included the analysis of the seeds quality by means of the germination, the tetrazolium, and the physical purity tests. Millet and grain sorghum had the highest dry matter (5,977 kg ha-) and grain ( 3,388 kg ha-) yields, respectively. Dwarf pigeon pea and forage turnip exhibited the highest levels of macronutrients. The incorporation of the preceding crop as green manure in association with N and P fertilization resulted in higher yields of seeds of better quality. When the preceding crop was dwarf pigeon pea, fertilizing with N was shown to be not needed due to its high N fixing capacity. Additional keywords: Brachiaria; green manure; dry matter; seed quality.