The objective of this study was to compare phosphate fertilizers in different methods of application during three successive maize cultivations in a Red Argisol (Hapludults) which had been previously fertilized. Treatments arranged in a 4x2+1 factorial design combined four P sources in the amount of 180 kg ha-1 P2O5 (triple superphosphate - TS, magnesium termophosphate - MT, Arad reactive rock phosphate - RP, and Araxá rock phosphate - AP), two application methods (broadcasted or banded in the seeding furrow), and a check plot (without P) as an additional treatment. The applied P ratio was based on the total P2O5 content of each fertilizer. After the first cultivation, the soil was no longer revolved. Soil and leaf nutrient concentrations, and the grain yield were determined. The responses to treatments were more contrasting initially and tended to level off with successive cultivations. In the first two cultivations, the most soluble sources (TS and MT) promoted greater yields. The rock phosphates (RP and AP) presented increased efficiency with time. Banded application of RP provided a higher grain yield in the third cultivation. The residual effect of previous fertilizations and the climatic conditions influenced the effects of the treatments.
Soil fertility; reactive rock phosphate; rock phosphate; phosphated fertilization; Zea mays
