Fertilizer trial for maize on red yellow latosol under "cerrado" vegetation

Abstract

A five year fertilizer field study was conducted in the São Simão Experimental Station in the State of São Paulo on a red yellow latosol developed under "cerrado" vegetation. A 3 x 3 factorial experimental design was used to study the influence of various combinations of nitrogen, phosphorus and potassium fertilizers on the growth of corn. The fertilizers were applied during each of the first three years of the five year study. Yields were highest on the treatment receiving 120 kg/ha N, 60 kg/ha P₂O₅, and 60 kg/ha K₂O (N₃P₂K₂). On and adjacent plot area several of treatments in the factorial were treated with zinc. Treatments N₂P₂K₂ and N₃P₃K₃ with zinc produced the highest corn yields and were not significantly different. The residual effect of zinc could not be measured. After analyzing the economical data obtained from the 27 treatments during the three years when fertilizer was applied no conclusions could be drawn as to the most desirable economical rates of fertilizer to use.