MODEL STATISTIKA PENENTUAN BATAS KRITIS HARA FOSFOR

Abstract

The method commonly used in the determination of soil nutrient availability classes is a graphical method of Cate and Nelson (1965) and a modified analysis of variance model (Nelson and Anderson, 1977). Another models could be used by researchers in determining the nutrients critical levels are Mitscherlich and square root (Reciprocal) models. This study aims to compare statistical models for determination of rice field phosphorus critical level. The research using multilocation experimental data of P fertilization on rice in Java, Sumatera and Lombok. Each trial consisted of four to five levels of P fertilizer treatment. Measured response is relative yield (percent). Soil properties measured was total P (25% HCl) nutrient content before the experiment. The design used was a randomized complete block design with three replications. Results showed that statistical models and sufficiency levels have an effect on critical levels of phosphorus nutrient. Sequentially the AIC value of the models are Reciprocal_1 (X) = Reciprocal_1 (lnX)< Reciprocal_2 (X)< Reciprocal_2 (lnX) < Mitscherlich (lnX) < Mitscherlich (X). The best model is the Reciprocal_1 in sufficiency levels of 90 or 95 percent. Keywords: Cate-Nelson, Mitscherlich, Square root (Reciprocal), AIC.