AGRONOMIC EVALUATION OF THE NORTH CAROLINE PHOSPHORIC ROCK IN A ULTISOL, IN A RICE-BEEN ROTATION CROP.

Abstract

In a typic isohyperthermic plintudult soil of Panama was evaluated the effect of doses, source and forms of application of the North Carolina Phosphoric Rock (NCPR) and Triple Super Phosphate (TSP) on a rice-been rotation crop. Highly significant differences were detected on evaluated doses. It was determined as possible response range biannual applications of NCPR or TSP at doses of 88 and 132 kg/ha of P for rice crop. In been as second crop, it was found that doses higher than 44 kg/ha of P do not increase yields. For yearling applications, optimum doses in rice was 44 kg/ha. The critical level of P-1048 rice variety in this soil is 2.3 ug/ml, while in vigna RH-209 been variety was 4.2 ug/ml.