高温高压间歇灭菌对中国典型土壤性质的影响

INFLUENCE OF AUTOCLAVING STERILIZATION ON PROPERTIES OF TYPICAL SOILS IN CHINA

以中国8种典型土壤（砂质潮土、壤质潮土、黄泥土、乌栅土、红壤、红黏土、赤红壤和砖红壤）为代表,首先比较土壤高温高压间歇灭菌前后细菌、真菌、放线菌的数量,以评估灭菌效果,其次评价灭菌前后主要土壤性质的变化,包括土壤有机质（OM）、比表面积（SSA）、pH、阳离子交换量（CEC）、游离铁铝氧化物（Fed、Ald）、电荷零点（ZPC）。结果表明,该方法可以达到理想的灭菌效果,对部分理化性质则会造成一定的影响。除砂质潮土和红壤高温高压灭菌后OM含量显著增加外,其他6种土壤的OM含量受该灭菌方法的影响不大;酸性和有机质含量高的土壤,pH受高温高压灭菌影响较大,而碱性和有机质含量低的土壤则影响不大;所有供试土壤的SSA均显著降低,而CEC和Fed,Ald没有显著变化;4种可变电荷土壤中,红黏土、赤红壤和砖红壤的电荷零点（ZPC）没有变化,而红壤的ZPC则显著降低,且未出现于本研究测定的pH范围内（pH2.5-8）。由于土壤是一个复杂的多物质体系,受高温高压灭菌导致其性质变化还有待进一步的研究。

Populations of bacteria,fungi,and actinomycetes in eight soils（Usti-Sandic primosols,Usti-Alluvic Primosols,Hapli-Stagnic Anthrosols,Gleyi-Stagnic Anthrosols,Ferri-Udic cambosols,Argi-Udic Ferrosols,Alliti-Argiudic Ferrosols,Rhodi-Udic Ferralosols） typical in China were measured before and after the soil samples were sterilized to evaluate effect of the sterilization under high temperature and high pressure.Then changes caused by the treatment were analyzed in basic properties,including organic matter（OM）,specific surface area（SSA）,pH,cation-exchange capacity（CEC）,free iron/ aluminium oxides（Fed,Ald） and zero point of charge（ZPC） of the soils.Results show that the method satisfied the requirements of sterilization,but affected some of the basic properties.OM was not affected in all the samples except for Usti-Sandic primosol and Ferri-Udic cambosols,where it increased greatly.Soil pH was obviously affected in acid soils or soils high in organic matter content,but not much in soils high in pH and low in organic matter content.SSA was lowered in all the studied soils,while CEC,Fed and Ald remained almost unchanged.Zero point of charge（ZPC） of all the four variable charge soils was not affected,except for Ferri-Udic cambosols where it was decreased significantly.As soil is a complicated multi-substance system,the effects of sterilization under high temperature and high pressure need further study.