为了探讨节水灌溉下土壤微生物特性和土壤酶活性的变化特征及其与土壤养分之间的关系，在华北平原旋耕条件下，研究了不同灌溉处理（常规灌溉 W1、节水灌溉 W2和无灌溉 W3，冬小麦全生育期总灌溉量分别为150，75，0 mm）对冬小麦田土壤微生物量氮、基础呼吸、土壤酶活性和土壤养分的影响。结果表明：减少灌溉量可显著降低土壤微生物量氮和土壤基础呼吸。随着灌溉量的减少，β－葡萄糖苷酶和多酚氧化酶活性随之降低；而 W3可显著提高脲酶活性。土壤含水量随灌溉量的减少而降低。水分胁迫可显著提高土壤有机碳和硝态氮含量，但有降低铵态氮含量的趋势。相关性分析可知，土壤微生物量氮与土壤铵态氮含量显著正相关。β－葡萄糖苷酶和多酚氧化酶活性均与土壤含水量和铵态氮含量显著正相关，β－葡萄糖苷酶活性与有机碳含量显著负相关；脲酶活性与有机碳和硝态氮含量显著正相关，而与土壤含水量显著负相关。可见土壤微生物特性和土壤酶活性受灌溉处理调控，并且与土壤 C、N养分的循环转化关系密切。%In order to investigated the dynamic change of soil microbial characteristics and soil enzyme activi-ties and the correlation among soil microbial characteristics,soil enzyme activities and soil nutrient,a field experi-ment was conducted to study the effects of different irrigation methods(conventional irrigation,saving-irrigation and no irrigation,150,75,0 mm of irrigation rate during winter wheat growing season respectively,named by W1,W2 and W3 respectively) on soil microbial biomass nitrogen,soil basal respiration,soil enzyme activities and soil nutri-ent in the winter wheat field.These results indicated that the reduction of irrigation rate decreased significantly soil microbial biomass nitrogen and soil basal respiration.With the decrease of irrigation rate,β-glucosidase and poly-phenol oxidase activities were decreased,but W3 increased markedly urease activity.Soil water content was de-creased as the irrigation rate decreasing.Water stress enhanced significantly soil organic carbon and nitrate nitrogen content,however,ammonium nitrogen content had a decreased trend under water stress.Soil microbial biomass nitro-gen was significantly positively correlated with soil ammonium nitrogen content.β-glucosidase and polyphenol oxi-dase activities were significantly positively correlated with soil water and ammonium nitrogen content,and there was a negative significant correlation between β-glucosidase activity and organic carbon content.Urease activity was sig-nificantly positively correlated with organic carbon and nitrate nitrogen content,but was significantly negatively cor-related with soil water content.The results suggested that soil microbial characteristics and soil enzyme activities were regulated by irrigation and they were correlated with recycling and transformation of C and N.
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