Studies on impact of forest fire on physical and chemical properties of soil under different vegetation types in Uttara Kannada district

Abstract

A study was carried out to analyse the impact of forest fire on the physical and chemical properties of soil under different vegetation types in Uttara Kannada district during 2021-2022. Composite surface soil samples (0-30cm) were collected from two vegetation types (dry deciduous and moist deciduous forests) and two canopy density classes (very dense and moderately dense canopy) along with three fire disturbance levels (completely fire affected, partially fire affected and non-fire affected). Three-factor factorial RBD was carried out with twelve treatments and three replications. The individual effect and interaction effect of factors were studied. The results revealed that soils of moist deciduous forests showed higher porosity (49.72%), pH (6.36), organic carbon (1.77%), organic matter (3.05%), available nutrients such as N (203.50 kg/ha), P2O5 (26.15 kg/ha), K2O (210.78 kg/ha), exchangeable Ca (4.86 meq/100g), Mg (2.15 meq/100g) and micronutrients viz., Mn (31.49 ppm), Fe (64.32 ppm), Cu (3.75 ppm), Zn (3.17 ppm). But bulk density (1.12 g/cc) and particle density (2.13 g/cc) were found lower. Soils under very dense canopy showed maximum pH (6.31), organic carbon (1.98%), organic matter (3.41%), available P2O5 (25.56 kg/ha), available K2O (211.73 kg/ha), exchangeable Ca (4.55 meq/100 g) and available S (18.61kg/ha). Soil bulk density (1.23 g/cc), pH (6.55) and available P2O5 (25.12 kg/ha) increased in the fire-affected soils while soil porosity (46.06%), organic carbon, organic matter, available K2O (188.49 kg/ha), available S (20.36 kg/ha), micronutrients viz., Fe and Cu decreased in the fire-affected soils.