关键词: 土壤质地, 棉花, 根际微生物, 土壤酶活性

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