Fertility of soils in the region of the tranzamazonic highway. I. Neutralization of the exchangeable aluminum in a Red-Yellow Podzolic soil

Abstract

Neutralization of exchangeable aluminum (1,0 me/100 g) under laboratory conditions was investigated by application of CaCO₃ p.a. in increasing doses - until 2 x Al⁺⁺⁺ - to 500 grams of soil samples, totalizing nine treatments with two replications for each treatment, including a control. Samplings at 2, 10, 15,20,45,60 and 80 days of incubation followed by analysis showed total neutralization of exchangeable aluminum at the dose corresponding to 2 x Al⁺⁺⁺, at 20 days incubation. Determinations proceded at 45,60 and 80 days for the same treatment showed 0,3 me/100 g of exchangeable increase at the 2nd day of incubation, going from 4,8 to 5,9 in the "2 x Al⁺⁺⁺ treatment. At the end of the test (80 days) such value had come down to 5,2.