Abstract:  In order to investigate the effects of soil texture on changes of microbial quantity and enzyme activity in cotton rhizosphere during cotton flowering and bolling-forming stages, cotton variety named ‘Luyan cotton 21’  was used as test material, the quantities of rhizosphere bacteria, fungi and actinomycete, as well as the activities of urease, phosphatase and invertase of three texture soils (sandy soil, loam soil and clay soil) were studied by pool culture. The results indicated that the quantity and enzyme activities of rhizosphere microorganisms were affected by both soil texture and the development of cotton. Both amounts of rhizosphere microorganisms and enzyme activities of three texture soils showed a single peak curve with low-high-low dynamic change with development of cotton during flowering and boll-forming stages. The rhizosphere microorganism quantity and enzyme activity peaked at full-bloom stage and 11 d after full-bloom stage, respectively. Amounts of bacteria, fungi and actinomycetes in sand soil were significantly or extremely significantly lower than those in loam soil or clay soil during whole flowering and boll-forming stages. Three kinds of microorganisms amounts in loam soil were higher than those in clay soil during stages except the stage of 11 d after initial flowering. Activities of urease, phosphatase and invertase in sand soil were significantly or extremely significantly lower than those in loam or clay soil during flowering and boll-forming stages. Three enzymes activities in loam soil were higher than those in clay soil during the period from initial flowering to 22 d after initial flowering, lower during other stages, although there is no statistically significant differences. Sum up, rhizosphere microorganisms activities of cotton during flowering and boll-forming stages were influenced by both development processing of cotton and soil texture. The present research provided refferances for rational arrangment of cotton production areas.

Key words: soil texture, cotton, rhizosphere microorganisms, soil enzyme activity

摘要： 为了明确不同质地土壤对花铃期棉花根际微生物数量与酶活性的影响，采用池栽方式，以‘鲁研棉21’为材料，研究不同质地土壤(砂土、壤土、粘土)种植棉花在花铃期根际细菌、真菌、放线菌的数量及磷酸酶、脲酶和蔗糖酶的活性特征。结果表明，随着花铃期棉花的生长发育，3种质地土壤的根际微生物数量和酶活性均呈低-高-低动态变化的单峰曲线，其峰值分别出现在发育最盛的盛花期和盛花期后11 d。在土壤微生物数量方面，砂土整个花铃期3种微生物数量均显著或极显著低于壤土和粘土；而壤土中的微生物数量仅在初花后11 d低于粘土，其他时段均高于粘土。酶活性方面，砂土整个花铃期3种酶活性均显著或极显著低于壤土和粘土；壤土在初花至花后22 d时高于粘土，其余时段低于粘土，但差异均不显著。综上，棉花花铃期根际微生物活性受生长发育进程和土壤质地的双重影响。研究为棉花生产合理布局提供依据。

关键词: 土壤质地, 棉花, 根际微生物, 土壤酶活性