Effect of Continuous Cotton Cropping on the Microbes Amount in Soil

This experiment studied the effects of continuous cropping to microbe amount cotton production regions soil in Changde of Hunan in 2011.Results showed that: Cotton continuous cropping decreased the culturable microbe amount.The number of different continuous cropping of microorganisms had significant differences.The cropping soil bacteria and actinomycetes amount decreased obviously after 5,10,15 years continuous cropping compared to the one year cropping,while a substantial increase in the number of fungi after 10 years of continuous cropping.The number of soil microorganism in different years of continuous cropping cotton fields varied throughout the growing period of cotton.The number of bacteria and fungi in the four growth period showed significant difference,the actinomycetes in the seedling stage were significant difference compared with other three growth periods.