Impact of biochar on the physicochemical properties of sandy loam soil under high temperature

Abstract

Climate is changing and affecting the world on multiple scales. The average temperature of the world has risen by 1.2 °C compared to that of pre-industrial times and is deemed to cross the threshold of 3 °C at the current century’s end. This average rise in temperature has direct impacts on agriculture and the physicochemical properties of soil, which are the basic parameters of soil health and fertility. To tackle the negative effects of temperature rise, on the properties of soils, especially during the hot summers of Pakistan, biochar amendments could be utilized. In this study, soil incubation experiments were performed to evaluate the effects of biochar under high temperature (50 °C) on physicochemical properties of sandy soil. Three types of biochars derived from the shells of coconut (CBC), almond (ABC) and walnut (WBC) were applied at 1%, 2% and 5 % rates. The results illustrated that biochar had significant impact on the physicochemical properties under high temperature. Biochar showed less rise in the pH and EC of the soil, thus proving beneficial for the alkalinity control. It increased the soil organic matter up to 52% as compared to control. An increase in water holding capacity to 53.34% was observed in the soil treated with ABC (at 2% application rate) as compared to control (39.04%). Decrease in soil bulk density was observed in the soil treated with biochar amendments. It decreased from 1.30% observed in control to 1.12% of CBC treated soil at the rate of 2%. The significant rise of 53.5% in aggregate stability was observed in CBC treated soil (at the rate of 2%) as compared to the control (36.6%). Total porosity was also significantly improved from 40.2% in control to 47.07% in the soil treated with CBC (at the rate of 2%). Among all the tested biochars, the CBC application at 2% rate is recommended under high temperature conditions to improve the various physicochemical properties of soil.