Grassland Management By Burning Alters Soil Physiochemical Properties Of Sandy Clay Loam Soil

The influence of fire on the physiochemical properties of grassland soils varies with soil texture. Understanding the nutrient fluxes associated with such fires at different soil depths is important for maintaining soil ecosystem functions and processes as well as grassland aesthetics. The study focused on the post-fire burnt and unburnt lawn at the Faculty of Agriculture, University of Nigeria, Nsukka. Soils were sampled in triplicates at the two sites with the aim of evaluating their physiochemical properties at 0-15, 15-30 and 30-45 cm depth. The results indicate that the unburnt soil was characterized by a sandy clay loam texture, good drainage, acidic, high soil organic matter content and low nutrient reserves. The post-fire burnt soil showed a significant decrease in silt (29%) content, and an increase in coarse sand (19%) content and saturated hydraulic conductivity (18%). Additionally, the burning increased soil C:N (51%) but reduced total N (18%) and soil acidity from 3.98 to 4.42 due to increased Ca2+ (38%) and the associated decrease in Al3+ (49%). The influence of grassland burning at the soil depths changed the sand, silt and clay content with a textural transformation to sandy loam at 0-15 cm depth. Soil available P decreased with soil depth, in addition to P addition (52%) at 0-15 cm depth. For reasons of climate change due to N loss from post-fire burnt soil, management of the grassland through burning should be avoided.