生物炭和保水剂施用对凉山州紫色土理化性质及水分特征的影响.

【Objective】Water shortage in dry season and nutrient deficit in Liangshan Prefecture, Sichuan Province are the main factors limiting agricultural production. The present paper aimed to investigate the effects of biochar and polyacrylamide on water and fertilizer retention capacity of purple soil in Liangshan Yi Autonomous Prefecture.【Method】The field experiment was carried out with biochar application rates of 0, 10, 20, 40, 60 t/hm~2, polyacrylamide application rates of 0, 45, 90, 135, 180 kg/hm~2. 【Result】Compared with control, the percentage of effective particle size of >50 μm increased by 8.9 % under 60 t/hm~2 biochar treatment, 7.4 % under 180 kg/hm~2 polyacrylamide treatment, respectively; the soil bulk density decreased by 17.0 % under the treatment of 60 t/hm~2 biochar, which was 1.08 g/cm~3, and decreased by 13.1 % under the treatment of 135 kg/hm~2 polyacrylamide which was 1.13 g/cm~3; The soil saturated water content increased linely with the increasing application rates of biochar, 60 t/hm~2 biochar treatment increased by 20.8 %, which was 51.2 %. However, the soil saturated water content, field water holding capacity and the capillary water content increased first and then decreased with the increasing application rates of polyacrylamide, and 180 kg/hm~2 polyacrylamide treatment increased by 23.5 %, 21.3 % and 25.0 % which was 53.9 %, 32.3 % and 45.6 %, respectively. For soil organic matter, the treatment of 60 t/hm~2 biochar, the treatment of 135 and 180 kg/hm~2 polyacrylamide were improved by 86.4 %, 146.4 % and 186.4 % which was 11.52,15.23 and 17.70 g/kg, respectively. 【Conclusion】The application of biochar and polyacrylamide can improve the soil structure and the ability of purple soil to store water and maintain fertilizer. The most suitable biochar and polyacrylamide application rate were found to be 60 t/hm~2 and 135 kg/hm~2, respectively. [ABSTRACT FROM AUTHOR]