Applicability of the Fertilizer-Yield Equation to Production of Sugar Per Acre in Puerto Rico

Abstract

The fertilizer-yield equation was used to describe the relationship between the applications of nitrogen, phosphorus, potassium, calcium and magnesium-bearing materials and the yield in tons of sugar per acre in 33 sugarcane experiments carried out in various regions of Puerto Rico. Similar curves were obtained when the equation was fitted using data in tons of sugarcane per acre (1,2). The B values estimated tend to be low for potassium and calcium and generally high for nitrogen, phosphorus and magnesium. C fluctuated from high to low values. This suggests it is more important to keep the levels of nitrogen, phosphorus and magnesium near their optimum levels than potassium and calcium. The coefficients of determination ranged from very good to very poor fit. From the practical standpoint, sugarcane per acre data may be more convenient for use in estimating optimum fertilizer applications than sugar per acre data.