DRY MATTER YIELD AND MACRONUTRIENT CONCENTRATION IN Brachiaria decumbens UNDER DIFFERENT MANAGEMENT SYSTEMS IN COASTAL REGION OF THE PERNAMBUCO STATE, BRAZIL

Abstract

The cultivation of pastures for long time under different management systems can cause alterations in the dry matter production and in the macronutrients concentration in shoots of plants. In an experiment carried out at the Pernambuco Agricultural Research Institute (IPA) experiment extension, district of Itambé, Pernambuco State, Brazil, the effects of different management systems in the dry matter production and macronutrients concentration in pasture shoots were studied. The management systems consisted of a fertilized area under Brachiaria decumbens pasture consortiated with Calopogonium mucunoides, a fertilized area cultivated with B. decumbens pastures, a non-fertilized area under B. decumbens pasture, and a non-fertilized pasture of B. decumbens and native leguminous of the genus Sesbania. The plant shoots were collected at 0.15 m height, for determination of shoot dry matter production and N, P, K, Ca, and Mg concentrations. The fertilized areas with B. decumbens or with B. decumbens consortiated with C. mucunoides promoted the greatest concentrations of N, P and K in the rainy and dry seasons, and greatest shoot dry matter production in the dry season, as related to the other studied treatments.

KEY-WORDS: Brachiaria; Calopogonium; Red-Yellow Argisol; coastal plain tablelands.