Qual a relação nitrogénio : potássio adequada para o capim mombaça?

Abstract

Potassium and nitrogen are the most demanded nutrients for grazing and are extracted from the soil in similar proportions. Therefore, the objective was to identify the combination of nitrogen and potassium that provides greater development of Mombasa grass. Two experiments were carried out in a greenhouse and the design was completely randomized with five treatments and four replications. Each experiment was carried out with different nitrogen doses in the Mombaça grass maintenance fertilizer (140 and 280 mg dm-3). The treatments consisted of five potassium doses (0, 70, 140, 210 and 280 mg dm-3). The evaluations were performed when the grass reached a height of 60 cm, collecting the vegetable mass above 30 cm in height. All variables were described by RLP (Response Linear Plateau) model, except for leaf number per tiller, which was not influenced by nitrogen and potassium combinations. When the nitrogen dose of 140 mg dm-3 was used, a plateau was observed at the potassium dose of 70 mg dm-3, while at the nitrogen dose of 280 mg dm-3, there was no change when fertilized with doses of 70 mg dm-3. from 101 mg dm-3 potassium. Thus, the nitrogen: potassium ratio of approximately 2:1 provides the highest development of Mombasa grass.