Residual effects of rock phosphate on soybean growth at tidal swampland South Kalimantan

Abstract

Abstract Phosphorus fertilizer application could be an option to improve soybean yield in Indonesia. As in tidal swampland, phosphate deficiency is one of the main obstacles in the soil because it fixates ferro as insoluble phosphates. This experiment aimed was to determine the residual effects of Reactive Phosphate Rock (RPR) in the second cropping season on soybean growth in tidal swampland of South Kalimantan. The experiment was conducted at Barambai Village, South Kalimantan. This study was set in a factorial randomized block design with sixth treatments and three replications. The treatments were farmer practice, P Fertilizer (SP 36), residual of RPR, residual of RPR with soluble P Bacteria, residual of RPR with mycorrhiza, residual of RPR with Rhizobium and Soluble P Bacteria. The residual effect of RPR treatments with rhizobium and soluble P bacteria in the second planting season gave higher plant height of soybean compared to farmer practice and SP 36 treatment. The residual effect RPR treatment with rhizobium increased soybean yield up to 40.9% compared to without RPR and microbe in second cropping season. The released soluble P derived from RPR is relatively slow, therefore the application of high-dose RPR increases crop production.