Short term effects of low intensity prescribed biomass combustion on soil physicochemical properties in degraded paleudult in enugu area southeastern Nigeria

The short-term impacts of prescribed combustion of wood shavings biomass (WSB) on soil properties were examined. The experimental five treatments comprising dried wood shavings biomass were spread uniformly on the experimental plots at the rate of 0, 12.5, 25, 37.5, and 50 tons ha⁻¹. The WSB was burned in situ to produce different fire intensities. The soil temperature in plots amended with prescribed wood shavings biomass of 50 kg ha⁻¹ was higher than that in other plots by 18–26%, respectively, at both soil depths. The highest bulk density (1.59 and 1.62 Mg m⁻³) were in plots amended with 50 t ha⁻¹ wood shavings biomass, and was higher than other. Soil saturated hydraulic conductivity in the plots amended with 37.5 and 50 t ha⁻¹ wood shavings biomass was lower) than that of the other plots by 33% in both soil depths. The volumetric water content and soil water droplet penetration time decreased with burn severity. In contrast, soil pH, soil organic carbon, total nitrogen, exchangeable potassium, calcium, and magnesium and available phosphorus increased with burn severity by between 5–66%, respectively, after biomass burning at the rates applied. During low intensity prescribed fires, volatile constituents of soil organic carbon are not entirely incinerated at soil temperatures <50°C, and the quantity of SOC at the surface in the short run determines thepercent SOC and other nutrients available in the topsoil.