Kajian Pemupukan Fosfor pada Tiga Tingkat Status Fosfor Tanah terhadap Tanaman Padi Sawah di Kabupaten Dharmasraya Sumatera Barat

Study of P Fertilization on Three Levels of Soil P Status Towards Lowland Paddy Field in the Dharmasraya District, West Sumatra Province. Based on phosphorus (P) status map (1: 250,000), from the total area of paddy soils in West Sumatra (225,165 ha), about 37,389 ha (16.6%) shows low level of P status, while 95,983 ha (42.6%) and 91,793 ha (40.8%) show medium and high P status, repectively. To obtain the specific fertilization rate based on the type of soil, it is necessary to study the effect of P fertilization and its residual effect on the high P status of lowland paddy soil. The research objective was to determine the optimum rate of P fertilizer on the three level of P status of paddy soils (low, medium, high) towards lowland paddy field in the production center area located in Dharmasraya district, which has Typic Hapludults soil type. Research had been done at three locations (low, medium, and high P status). The first planting season tested five levels of P fertilizer rates. The rates were 18, 36, 72, and 114 kg P2O5 per ha in three P status (low, medium, high) using a Randomized Completely Block Design with four replications. Based on the sufficiency and balance of P in the soil, the optimum rates of P fertilizer for each P status (low, medium and high) were 88.58 kg P2O5/ha; 74.86 kg P2O5/ha; and 0 kg P2O5/ha, repectively