Nutrient Uptake and Dry Matter Accumulation by Intensively Managed Pigeon Peas Grown on a Corozal Clay, An Ultisol

Abstract

Pigeon peas grown on a typical Ultisol of the humid mountain region of Puerto Rico and fertilized with 450 kg/ha of 10-10-10 took up an average of 216, 12, 168, 54 and 19 kg/ha of N, P, K, Ca and Mg, respectively, over a planting-to-harvest season of 147 days. Total dry matter production and yield of mature-green pods were 12,340 and 8,104 kg/ha, respectively. Computations based on nutrient uptake, available nutrients in the soil, capacity of pigeon peas to fix atmospheric N, and losses of fertilizer nutrients showed that to support near optimum yields of pigeon peas, applications of 296, 32, 211, and 30 kg/ha of N, P₂O₅, K₂O and MgO, respectively, are required. These amounts are roughly equivalent to those of the nutrients in 2,000 kg/ha of 15-2-10-2 commercial fertilizer. The fertilizer should be applied in two equal portions 3 and 10 weeks after planting.