Abstract:Field plot experiments were conducted to study the effects of biochar on the hehavior of soil moisture, temperature, organic matter and available nutrient contents in different growth periods of maize under mulched drip irrigation conditions. The dosages of biochar were set at 0 t/hm2 (A0), 15 t/hm2 (A15), 30 t/hm2 (A30) and 45 t/hm2 (A45), respectively. Results showed that, with the increase of biochar use, soil moisture increased first and then decreased in plough layer during the growth period of maize. Soil moisture in the treatments with biochar were higher than that in control (A0), significant differences were observed in the jointing, tasseling and filling stages of maize and the highest increase rate (13.74%) was found in A30. At three-leaf stage and early jointing stage, biochar application increased the temperature of surface soil layer remarkably. At tasseling, filling and maturity stages, the temperature of surface soil layer followed an order of A30>A0>A45>A15, with no significant correlation to biochar rate. Moreover, organic matter and available phosphorus contents in plough soil layer increased with biochar rate. During the growth period of maize, as compared with control (A0), soil organic matter contents in A15, A30 and A45 increased by 14%, 20% and 58%, while available phosphorus by 62%, 99% and 113%, respectively. The application of biochar significantly increased alkali-hydrolyzable nitrogen and rapidly available potassium contents in plough soil layer. In comparison with control (A0), alkali-hydrolyzable nitrogen of A15, A30 and A45 increased by 13%, 17% and 10%, while rapidly available potassium increased by 35%, 48% and 63%, respectively. In conclusion, biochar use under mulched drip irrigation effectively increased soil moisture, temperature, organic matter and rapidly available nutrients in plough soil layer, which indicate that biochar could maintain soil water-heat-fertility, is of great significance in improving soil water and fertilizer use efficiency.