The Impact of Biofertilizers and NPK Fertilizers Application on Soil Phosphorus Availability and Yield of Upland Rice in Tropic Dry Land

Dry land in Indonesia is dominated by marginal soil which have low macro nutrient content, low organic matter content and low soil microbial activity. Improving soil quality it is necessary to increase nutrients availability such as biofertilizers application. Biofertilizers contains beneficial microbial inoculants to increase soil nutrient availability. The use of biofertilizers combined with NPK fertilizer will increase macro nutrients availability and optimize plant growth, thus will increase fertilizers efficiency. This experiment was carried out to study the impact of biofertilizers on available-P, plant P-uptake and yield of upland rice at Land Research of Agriculture Faculty, Universitas Padjadjaran. This experiment used a randomized block design consisting of ten treatments and three replications The treatments consisted with two doses of biofertilizers (50 kg ha(-1) and 75 kg ha(-1)) and three doses of N,P,K fertilizers (100%, 75%, and 50% from recommended doses). Biofertilizers contains N-fixing bacteria and phosphate solubilizing microbes. The result of experiment showed that application of biofertilizers 75 kg ha(-1) and biofertilizers 50 kg ha(-1) + N, P, K 50% increased soil phosphorus availability. The application of biofertilizers increased P-uptake up to 81%. Futhermore, biofertilizers 75 kg ha(-1) + N, P, K 75% increased the yield of upland rice by 164%.