生物质炭对旱地红壤理化性状和水力学特性的影响

目的]研究生物质炭对旱地红壤基本理化性质及水分特征曲线的影响,为红壤地区土壤改良提供依据。方法]分层测定不同生物质炭施用量水平下的土样容重、孔隙度和有机碳含量,采用原状土压力膜法分层测定土壤的水分特征曲线。结果]施用生物质炭能显著降低土壤的容重,提高土壤的孔隙度及有机碳含量,且随着施用量的增加,土壤容重逐渐降低,孔隙度及有机碳含量逐渐提高;随着生物质炭施用量的增加,土壤饱和含水量、田间持水量和有效水含量逐渐增加,凋萎系数逐渐减小,施用生物质炭30t/hm2的土壤处理饱和含水量、田间持水量和有效水含量最高;生物质炭施用量与土壤饱和含水量、田间持水量和有效水含量呈极显著正相关关系,与凋萎系数呈极显著负相关关系。结论]施用生物质炭能显著提高红壤田间持水量和有效水含量。

Effects of Biochar on Physicochemical Properties and Hydraulic Characteristics in Upland Red Soil

Objective] The impacts of biochar on the physicochemical properties and hydraulic characteristics were assessed in order to guide the improving of the red soil at uplands.Methods] Soil bulk density and porosity were measured for samples of two different layers of undisturbed red soil treated with varying amount of biochar, and curve of soil water characteristics were studied by pressure membrane method.Results] Application of biochar could significantly decrease bulk density as well as improve porosity and soil organic carbon content. With the increase of application amount, soil bulk density decreased; While porosity and soil carbon content increased gradually. Soil saturation moisture content, field capacity and available water content increased and wilting coefficient decreased with the increasing application of biochar. The saturated moisture content, field capacity and available water content were at their highest when the application biochar was 30 t/hm². The application amount of biochar was significantly and positively correlated with soil saturation moisture content, field capacity and available water content, and had significant negative correlation with wilting coefficient.Conclusion] Application of biochar can significantly increase field capacity and available water content of red soil.