Effectiveness of biochar in soil conditioning under simulated ecological conditions

Biochar is getting momentous importance due to its potential use in various fields like agriculture, organic fertilizers and green house gas (GHG) sequestration. The mineralization of biochar in soil is greatly dependent upon the temperature and moisture level of the soil, therefore under simulated ecological conditions, there is varying effect of biochar on soil properties. In the present study, the potential of biochar to improve soil properties was focused under simulated ecological conditions of Pakistan. Experiments were carried out on soils of seven ecological zones of Pakistan applying biochar in 0.6:100 ratio (biochar: soil, w/w) in pot experiments. Temperature and moisture conditions of the experiments were maintained in laboratory according to the respective ecological zones. The effect of biochar was periodically analyzed for two months on various soil parameters such as pH, bulk density, organic matter, total organic carbon and available phosphorus. The results showed that the alkaline nature of biochar contributed to high shift in pH of all the ecological zones. Maximum rise (0.5 units) was observed in Zone 10 (Sulaiman Piedmont, Temperature (T): 46 degree C; Field Capacity (FC): 26%). The biochar application showed a decrease in bulk density of the soil of all ecological zones. The high carbon and nutrient content of the biochar contributed to increase in total organic carbon, organic matter and available phosphorus of soils of all the ecological zones. The most profound effect of biochar was observed for Z6 (Wet mountains, T: 36 degree C, FC: 50%), where the concentration raised from initial 1.15 mg per kg to 2.43 mg per kg. Overall, the study revealed that ecological zones of Pakistan with higher moisture level and temperature conditions cause increase in mineralization of biochar and contributed to nutrients release in the soil which ultimately improved the soil properties.