Effects of three relay intercropping patterns on watermelon growth and soil microflora in continuous cropping

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.