Oat fertilization in two planting systems

Abstract

The objective of this work was to determine the best rates of N, P, and K to obtain maximum economic return per area of forage yield for the oat line UPF 87111 grown in two planting systems i.e conventional tillage and with a corn-residue mulch. The experiments were carried out in a Dark-Red Latosol (Hapludox). The experimental design was a incomplete (1/2)4³ factorial, with two randomized blocks, with a total of 32 plots, without replication. The treatments comprised four rates of N and K₂O (0, 70, 140, and 210 kg ha^-1), using urea and potassium chloride, respectively, and four rates of P₂O₅ (0, 60, 120 and 180 kg ha^-1), using triple superphosphate. The N, P, K rates for maximum profit were, in kg ha^-1 for conventional tillage: N = 165, P₂O₅ = 50, K₂O = 53; and for mulch-covered field: N = 210, P₂O₅ = 90, resulting in forage yields of, respectively, 6,641 and 7,322 kg ha^-1 of dry matter. In both planting systems there was response only to N, and its use resulted in higher forage yield per unit of applied fertilizer.