Effect of rock phosphate and superphosphate fertilizer on the productivity of maize var. Bisma

摘要: Superphosphate (SP) fertilizers have been used widely to improved food crop production in Indonesia. However, the high cost of SP is now focusing attention on rock phosphate (RP) fertilizer as a natural phosphorus (P) source and because its relatively low cost. A field experiment was conducted evaluate effects RP SP-36 interaction between treatments productivity maize Latosolic soil (low available Bray-II extractable P). split-plot design with three blocks replicates used, sources P main plots four levels subplots. Results showed that increased grain yield, dry matter (DM) stover crude protein (CP) contents over those control did not receive fertilizer. Superphosphate-36 application resulted higher DM CP than crops treated at same rate. The highest P-use efficiency for obtained provided 66 kg ha−1.