Phosphorus Agronomic Efficiency Index Under Different Fertilizer Application Methods in Two Cycles of Sugarcane Cultivated in Tropical Soils

Abstract

ABSTRACT Our objective was to evaluate the agronomic and industrial sugarcane parameters under different P application methods in two cycles of sugarcane cultivated in tropical soils with different mineralogic composition. The experiment was carried out in sandy (PVAd1), sandy-clay (PAdx) and sandy-clay-loam (PVAd2) soils during two sugarcane cycles (plant-cane and ratoon-cane). We tested the localized and non-localized application methods of P with and without fractionation of the P rate. We evaluated extraction, allocation, and efficiency use of P, as well as the growth, yield, and technological quality of the sugarcane. The non-localized application provided greater P extraction, regardless of the soil mineralogy, however showed a greater residual effect in ratoon-cane in the PVAd1. The non-localized application increased the P content in the juice in plant-cane in the PVAd2 but reduced the recoverable sugar. The agronomic efficiency index showed that the localized application is suitable for PVAd2 while the non-localized application is recommended for PVAd1 in plant-cane. Thus, the non-localized application and the P fractionation showed better agronomic and industrial parameters in tropical soils, especially on the sandy despite the localized application being the traditional method.