Lime and P-fertilizer management for acid upland soils grown to rice.
1992
Novero R.P. | Aragon E.L. | Pabico J.P.
Acid upland soils which occur widely in humid tropical areas are a big potential for increasing the world's rice production. However, problems of P deficiency and soil acidity are associated with acid soils. Proper soil fertility management technique therefore must be developed to increase the productivity of such soils. The study was conducted at two sites, Cavinti, Laguna, and Claveria, Misamis Oriental [Philippines]. The trial in Cavinti began in 1984 and the one in Claveria, in 1986. Several sources and rates of P were tested with or without lime. Rice grain yield (GY) and dry matter (DM) were determined. Changes in soil chemical properties were monitored. Dry matter and GY of cowpea, the dry season crop were measured. Initially, upland rice had no immediate response to lime application and little to P fertilizers. However, GY and DM in all fertilized plots improved with time while those of the control gradually declined. The same response was observed in the nonfertilized cowpea. Combination of lime and P consistently showed the highest response from both rice and cowpea especially at Cavinti suggesting that both materials are needed to improve crop yields. With time, slight improvement in some soil chemical properties was observed in all plots fertilized with combined P and lime.
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