Abstract: With cucumber (Cucumis sativus L.) variety Jinyou 1 as test material, a greenhouse experiment was conducted to study the effects of different water an d fertilizer supply on the cucumber soil nutrient content, enzyme activity, and microbial diversity. Three water regimes (50%〖KG-*2〗-〖KG-*7〗60%, 70%〖KG-*2 〗-〖KG-*7〗80%, and 90%〖KG-*2〗-〖KG-*7〗100% soil relative moisture content) and two fertilization practices (600 kg N·hm-2 + 420 kg P2O5·hm-2 and 420 kg N·hm-2+294 kg P2O5·hm-2) wer e designed. The increase of water and fertilizer supply benefited the increase o f soil available P content and sucrase activity. Increasing fertilization rate i ncreased soil NH4+-N content but decreased soil protease activity, and incr easing soil relative moisture content decreased the soil NH4+-N content and urease activity. Soil microbial diversity had no significant correlations with soil nutrient contents, but significantly positively correlated with soil urease activity and negatively correlated with soil sucrase activity. Among the treatm ents, the treatment 70%〖KG-*2〗-〖KG-*7〗80% soil relative moisture content + 6 00 kg N·hm-2 and 420 kg P2O5·hm-2 had the highest soil nutrien t contents, soil urease, sucrase, and phosphatase activities, and soil microbial diversity and evenness, being the best in soil potential productivity.

Key words: poplar plantation, ion exchange resin membrane, nutrient availability, soil enzyme activity, canonical correlation analysis.