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