Correção da acidez do solo e desenvolvimento do sistema radicular do amendoim em função da calagem

Abstract

To study the effects of liming on soil acidity and root growth of peanut, a field experiment was carried out, in Botucatu, State of São Paulo, Brazil. Two peanut cultivars (Tatu and Tupã), grown in four rates of lime (0, 4, 6 and 8 t/ha) were studied in a Dark Red Latosol (Haplortox) on a split-plot experiment with three replications. Liming decreased soil acidity and increased calcium and magnesium contents up to 40 cm depth. These effects were observed three months after liming and lasted at least sixteen months. Soil acidity parameters were related to peanut root density, in the plant rows, in the 0-20 cm soil layer. Root density was best related to calcium concentration in the soil, irrespective of cultivars. The highest root density occurred in the 0-20 cm soil layer. Liming increased calcium uptake by peanut, and highest absorption was observed when calcium reached in the soil 25.3 mmolc /dm3, in the 0-20 cm layer, and 8.9 mmolc /dm3, in the 20-40 cm layer. Calcium uptake was similar to two cultivars.