Effectiveness of phosphorus fertilizer on soybean plants in the coastal sands soil

Abstract

The study aimed to determine the effectiveness of P fertilization on soybean plants in coastal sands soil. Pot research in the field using complete randomized block design with four replications. Treatment factors include soybean cultivars namely Anjasmoro, Demas 1, Gema, and Gepak Ijo; and P fertilizer dosage consisted of 0, 36, 72, and 108 kg P2O5 ha−1 or equivalent to 0, 100, 200, and 300 kg SP36 ha−1. Data were analyzed using variance analysis, continued with Duncan's Multiple Range Test at 5% error level. The results showed the interaction of soybean cultivars with P fertilizer dosage on all observed variables. The growth of leaf area and P uptake of soybean plants increased by P fertilization until the optimum dose depends on soybean cultivars. The dry weight of plants and soybean yields on Anjasmoro, Demas 1 and Gepak Ijo cultivars increased by fertilizing SP36 up to the optimum dose and no further increased or even decreased at higher P fertilizer doses. P fertilization on Gema cultivar showed ineffectiveness based on leaf area, plant dry weight and the yield of seeds which were actually inhibited by P fertilizer.