Soil acidity correction and nutrient availability as a function of segmental liming

Resumen

Segmental liming involves the incorporation of lime into the subsoil as narrow seams, typically associated with deep ripping. This study aimed to evaluate the vertical and horizontal distribution of soil acidity and nutrient availability in a Ferralsol under no-tillage after five months of segmental liming. The equipment used for segmental liming had seven rods with a spacing of 70 cm, and a working depth of 40 cm. The lime rate used was 1 Mg ha^-1 of limestone with high effective neutralizing power (ENP = 170%). The soil was sampled in eight layers (0–5, 5–10, 10–15, 15–20, 20–25, 25–30, 30–35, and 35–40 cm), in the passage line of the equipment and at 10, 20 and 30 cm to the side between rods. Soil available P and K was not changed horizontally and vertically due to segmental liming. On the other hand, the 10-25 cm soil depth in the rods application line increased the soil pH from 5.3 to 5.9, the exchangeable Ca from 60 to 78 mmol_c kg^-1, the exchangeable Mg from 21 to 32 mmol_c kg^-1, the base saturation from 56 to 73%, and decreased the Al saturation from 11 to 2%, compared to the samples collected at 10, 20 and 30 cm from the segmental liming application line. Soil acidity correction by segmental liming was restricted to the chisel line, which represented a correction of soil acidity in only 14.2% of the useful area of the crop.