Phosphor rate for vegetable grown in the ultisol: Nanggung, Bogor, Indonesia

Amaranth (Amaranthus sp), Kangkung (Ipomoea aquatica L), Eggplant (Solanum melongena L), Chili (Capsicum annuum L), Tomato (Lycopersicon esculentum Mill), Green Bean (Pahaseolus vulgaris L), and Yard Long Bean (Vigna unguilata L) were grown on Ultisol Nanggung soil with low pH (5.2), low C-Organic (1.70%), very low N-total (0.21 %), low K content (0.33 me/100 g), but high soil P2O5 concentration (10.8 ppm) to optimize P rate application. Treatments were P rate : 0, 45, 90, 135 and 180 kg P2O5ha-1 or equal to 0, 125, 250, 375 and 500 kg SP36 (36% P2O5) ha-1. Treatments were arranged in Randomized Completely Block design with three replications. In the level of soil P concentration of 10.8 ppm (Bray-1) of Ultisol, application of P fertilizer up 180 kg P2O5 ha-1 increased linearly plant height of kangkung, eggplant, chili, tomato, yard long bean and green bean and increased linearly yield of amaranth, kangkung, eggplant, chili, tomato and green bean. To achieve optimum P fertilizer rate, the range of P rate application needs to be increased.