生物炭添加对皖南旱地土壤物理性质及水分特征的影响

Effects of Biochar on Soil Physical Properties and Water Retention Characteristics of Upland in South Anhui Province

为明确生物炭添加对皖南旱地典型土壤供水能力的影响,采用室内模拟实验,研究了3种生物炭(竹炭、稻炭和烟炭)及3种添加比例(2%,5%,10%)对皖南旱地土壤物理性质及水分特征的影响。结果显示:土壤容重随生物炭添加量的增加而减小,土壤总孔隙度、毛管孔隙度、吸湿系数、凋萎湿度、饱和持水量及田间持水量随生物炭的添加而呈增加的趋势,竹炭2%、5%和10%添加处理及稻炭与烟炭5%和10%添加处理在降低土壤容重、增加孔隙度、吸湿系数、凋萎湿度、饱和持水量和田间持水量较对照有差异显著(P<0.05)。随着生物炭添加量的增加,土壤有效水分范围进一步增大,速效水与中效水含量增加,提高了土壤对作物的供水能力;同时,生物炭在一定程度上减少了水分蒸发,提高了土壤的保水保湿能力。因此,合理施用生物炭对改善土壤供水能力有着重要作用,在我国南方红壤旱地中有很强的适用性。

A batch of lab experiments was conducted to investigate the effects of 3 biochar materials（from bamboo,rice and tobacco stems） on soil physical properties and water retention characteristics for a better understanding of the role of biochar in soil water supply capacity. The biochar addition rate was set as 2%, 5% and 10% of soil. Results showed that soil bulk density decreased, while soil total porosity, capillary porosity, moisture adsorption coefficient,wilting moisture capacity, saturated water capacity and field water capacity increased significantly with increasing biochar addition rates（P〈0.05）. Again, soil available water increased in a various range, and the rapidly and moderately available water capacity increased. At the same time, the addition of biochar decreased water evaporation rate and increased water retention capacity. Therefore, biochar application at a reasonable rate would improve soil water supply of uplands in south China.