Recuperação de capim Mombaça estabelecido com omissão parcial e total de macronutrientes primários

Abstract

The objective of this research was to verify if it is possible to recover the productivity of the Mombaça grass, which was implanted in primary macronutrients omission, and to identify the most limiting nutrient for the implantation of this grass in Oxisol with low nutrients. Treatments consisted of Mombaça grass implantation in: omission of nitrogen (without N), phosphorus (without P), potassium (without K), omission of this three nutrients (without NPK) and presence of this nutrientes (with NPK). Experimental design was completely randomized with five treatments and three replicates. Each experimental unit consisted of a vessel with a capacity of 8.0 dm³ containing three plants. Thirtyone days after sowing, the standardization cut and maintenance fertilization with NPK were performed in all treatments. Twenty days after the standardization cut, the height of the plants was measured, counting the tillers and leaves number and measuring the forage mass, assuming residue height of 20 cm. This procedure was repeated two more times, which totaled three evaluations. Nutrients omission affected forage mass in first regrowth of Mombaca grass, the nutrient that most restricted the development was phosphorus. Maintenance fertilization recovers nutrientes omission in Mombaça grass implantation, however, under field conditions, due to the greater water deficit, it is probable that the recovery will be later than observed in this research. Thus, for the establishment of pastures of this forage, in Cerrado soil, it is recommended to perform, as a matter of priority, the phosphate fertilization.