茬口对大豆苗期生物学性状及根部病虫害的影响

通过盆栽试验，对大豆正茬土、重茬土、迎茬土及连茬土施入有机肥，测定其土壤有机质含量变化对大豆苗期生物学性状及根部病虫害的影响。试验表明，正茬土的土壤环境优于其他3种茬口土壤，重茬土是最不利于大豆生长的土壤环境。施入有机肥后，4种茬口土壤有机质含量均有明显提高，提高幅度为14．8％～36．9％，对土壤酸碱度的影响不大。大豆根部病虫害的发生在正茬土中较轻，在其他3种茬口土壤中发生较重。施有机肥后能加重大豆根部病虫害的发生。

Effect of Stubbles on Biological Characters and Root Diseases and Insect Pests at Soybean Seedling Stage

The effects of stubbles and organic fertilizer application on soil organic matter content, soybean biological characters, and root diseases and insects pests at soybean seedling stage were studied, by pot culture tests and under the soil conditions of rotation stubble, replication stubble, intermittent working stubble and succession cropping stubble. The tests showed that any of the soil environment of the rotation stubble was better than any of the other three stubbles. Replication stubble soil was unfavorable for growing soybean. The soil organic matter of the four stubbles all increased obviously after the application of organic fertilizer, the increase rate of which ranging from 14.8% to 36.9%. The changes of soil pH were not too great when organic fertilizer was applied. The happening of the soybean root diseases and insect pests in the rotation stubble soil was lower than that of any other three stubbles. The soybean root diseases and insect pests were more serious after the application of organic fertilizer.