Variation of Microflora in Cucumber Rhizosphere of Continuous Cropping in Greenhouse
[Objective] The aim was to study the occurrence mechanism of cucumber replant disease.[Method] The greenhouses with planting years of 1, 3,5,7 and 8 were selected and the tilling layer soil in root zone of 0 - 20 cm was collected to determine the microbial group and quantity.[Result] The microbe quantity in the soil continuously cropping for 5 yr was the most, reaching 2.2 × 108 cfu/g dry soil and that in soil for 8 yr was least, being 2.7 × 107 cfu/g dry soil.The bacteria accounted for more than 97% of total microbe number.With the increase of continuous cropping year, the quantity of bacteria and actinomycetes showed the tread of first increase and then decrease and reached the biggest value at 5 yr, being 2.17×108 and 1.92 ×106 cfu/g dry soil resp.The fungi quantity showed the increasing tread with the increase of continuous cropping year.With the increase of continuous cropping year, ammonifying bacteria, azotobacter and cellulolytic bacteria showed the tread of first increases and then decreases and reached the biggest value at continuous cropping for 5 and 3 yr, while the nitrifying bacteria quantity was decreased sharply with the increase of continuous cropping year.[Conclusion] Continuous cropping cucumber obviously changed the microflora in rhizosphere.
国家科技期刊平台
NSTL
万方数据
维普
