The Effect of N, P, K and Si Fertilizers on Some Soil Chemical Properties, N, P uptake and Growth of Black Rice (Oryza sativa L. indica) in Ultisols

This study aims to determine the effect of the combination of fertilizers N, P, K, and Si on the pH, N-total, Al-dd, N, P- uptake, and grown of black rice (Oryza sativa L. indica) in Ultisols from Jasinga. This research was conducted from October 2021 to January 2022 at the Experimental Land for Soil Chemistry and Plant Nutrition in Jatinangor, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor, Sumedang, West Java with an altitude of 752 meters above sea level. The experimental design was carried out using a Randomized Block Design (RAK) consisting of eight treatments and three replications, consisting of: control; 1 N, P, K without Silica; 1 N, P, K + ½ Silica; 1 N, P, K + 1 Silica; 1 N, P, K + 2 Silica; ¾ N, P, K + 1 Silica; ¾ N, P, K + 1½ Silica; ¾ N, P, K + 2 Silica; and without N, P, K + 2 Silica. The results showed that the combination of fertilizer doses of 1 N, P, K (Urea 300 kg/ha, SP-36 100 kg/ha, and KCl 100 kg/ha) with 1 Silica (2 mL/L) gave the best black rice yields in increasing plant height by 60.34 cm and number of tillers 34, plus those dose is the best dose in increasing soil pH by 5.63, but the fertilizer dose was not able to increase soil P-Availability and N-Total.