Effects of amendment and phosphatic fertilizing in a red-yellow podzolic soil

Abstract

This work was carried out in a green house where a preliminary study was done on the action of CaCO₃, in the neutralization of the exchangeable aluminum present in the soil and the effect of phosphorus on corn development. The soil used had a pH of 4.1 and exchangeable aluminum 0.9 me/100 gm of soil. The treatments, consisting of varying amounts of an amendment and a phosphatic fertilizer, were arranged in a 3x3 factorial design with four replications. Calcium carbonate (Guaranteed Reagent) was used as an amendment and as source of P₂O₅. Triple Super phosphate 40-45%. The CaCO₃ was applied to the soil (in 3 kilogram pots) 30 days before the employment of fertilizers. Applications of P₂O₅ as well as N and K₂O were added to the pots at planting time. Seeds used were of the Amarelão variety. The soil pH for the highest level of CaCO₃ at the end of incubation was 4.5. This same amount of amendment neutralized 63% of the exchangeable Al after a period of thirty days from application and 72% after 75 days, at the time of harvesting. According to the statistical interpretation of data obtained it is permissible to conclude that: 1) maximum growth of plants in relation to plasphorus is between the O and 2 levels; 2) maximum growth of plants was not obtained with the CaCO₃ levels employed; 3) there was no interaction between phosphorus and lime.