三种套作模式对连作西瓜生长和土壤微生物区系的影响

摘要

在发生西瓜连作障碍的土壤上,将香葱、芹菜、大蒜三种作物分别与西瓜套作,对西瓜生长状况及土壤微生物区系特征进行了研究.结果表明:三种套作处理均促进了西瓜生长,其株高增长明显,分别为对照的1.82、1.24和1.68倍,套作香葱对提高西瓜根系参数效果最好,根系活力为对照的2.67倍.套作香葱后土壤中细菌数量比套作前增加了154.83％,套作芹菜使放线菌数量增加48.00％,套作大蒜土壤真菌数量减少了75.01％,套作香葱土壤微生物总量比对照提高了1.80倍.套作香葱可有效提高连作西瓜株高、叶绿素含量及根系参数,能显著改善西瓜连作土壤微生物的数量和区系,从而缓解西瓜连作障碍.%Relay intercropping experiments with onion and watermelon,celery and watermelon, and garlic and watermelon were carried out to study the watermelon growth and soil microflora characteristics in the soil where watermelon continuous cropping obstacle occurred. The results showed that all the three relay intercroppings promoted the watermelon growth and increased the watermelon plant heights respectively by 82% ,24% and 68% over the control; The relay intercropping with onion and watermelon gained the best effect on improving watermelon root parameters,increasing the watermelon root activity by 1.67 times over the control, and also increased the soil bacteria count by 54.83%; The relay intercropping with celery and watermelon increased the actinomycetes by 48.00%; The relay intercropping with garlic and watermelon decreased the fungi by 75.01%; The relay intercropping with onion and watermelon improved the soil microorganism amount by 1. 80 times. The comparative analysis indicated that the relay intercropping with onion and watermelon could effectively improve the plant height, chlorophyll content and root parameters of successional crop watermelon and significantly improve the soil microorganism amount and microflora,thus relieving watermelon continuous cropping obstacle.