Impact of Bush Burning on Chemical Properties of Some Soil in Igboora, Oyo State, Nigeria

Soil is used in agriculture as an anchor and primary nutrient base for plants, and the types of soil and available moisture determine the species of plants that can be cultivated. Bush burning, whether as result of a wildfire or a controlled burning, affects not only the appearance of the landscape, but the quality of the soil. Bush burning method of land clearing is a traditional farming system used as a means of land clearing for crop production. This method of land clearing has both beneficial and detrimental effects on soil physical and chemical properties. Therefore, this study investigated the effects of bush burning on soil chemical properties at different soil depth of 0-30 cm and 30-60 cm respectively base on the rooting depth of crop planted. The experiment was carried out in six selected farms in Igboora, Ibarapa central Local Governmental, Oyo State. The soil sampled were collected from burnt and unburnt experimental soil and analyzed using USDA standard methods for soil analysis for the selected chemical characteristics (pH, Ca2+, Mg2+ Na+. TN and P). Two samples were taken from each burnt and un-burnt locations at depth of 0-30 and 30-60 cm. Paired t-test was used to compare means value of soil chemical properties determined from burnt and un-burnt soil. ANOVA was used for significance difference between soil from burnt and un-burnt soil. pH increased from moderately acidic to slightly acidic, phosphorus content of the soil increased greatly from un-burnt soil to burnt soil at 0-30 cm and 30-60 cm depths from 6.64 to 22.21 ppm and 3.53 to 24.95 ppm, respectively. Similarly, potassium increased from 0.27 to 0.40ppm at 0-30cm depth but decreased from 0.23 to 0.17 ppm at 30-60 cm depth. Nitrogen reduced at both depths from 0.80 to 0.76% and 0.72 to 0.68% respectively. Magnesium also increased from 1.3 cmol/kg to 2.00 cmol/kg and 1.65 to 1.75 cmol/kg at both 0-30 cm and 30-60 cm depth respectively. Whereas calcium showed a reduction from 3.17 to 2.85 cmol/kg and 1.65 to 1.45 cmol/kg at both depths. The variations observed between burnt and un-burnt soil for Ca, Mg, exchangeable acidity, pH, Nitrogen, potassium was significant at p<0.05 probability level. This indicates that bush burning has an impact on soil physical and chemical properties which may affect the suitability of the soil for crop production. Based on this, there is need for environmental education for farmers in the area in order to know the implications of bush burning on soil properties for soil sustainability which will boost food production.