连作对植棉区土壤微生物数量的影响

摘要

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 actino-mycetes 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 differ-ent years of continuous cropping cotton fields varied throughout the growing period of cotton .The number of bacteria and fun-gi in the four growth period showed significant difference , the actinomycetes in the seedling stage were significant difference compared with other three growth periods.%2011年，对湖南常德植棉区不同连作年限棉田土壤中可培养微生物的数量变化进行了研究。结果表明，棉花连作导致土壤中可培养微生物数量减少，不同连作年限棉田的土壤微生物数量差异显著，连作5、10和15年的棉田与种植1年的棉田相比，土壤中的细菌和放线菌数量明显减少，而真菌数量在连作10年后大量增加；在棉花的整个生育期，不同连作年限的棉田土壤微生物菌群数量因生育期的不同而有较明显的差异，其中细菌和真菌数量在4个生育期（苗期、现蕾期、花铃期、吐絮期）的差异显著，放线菌在苗期的数量与其他3个生育期的差异显著。