The Effects of Catch Crops on Properties of Continuous Cropping Soil and Growth of Vegetables in Greenhouse

Continuous cropping has become a key factor limiting the sustainable development of greenhouse vegetables. It is a matter of great importance to maintain and improve the effective fertility of greenhouse soil. Catch crops planted as green manure is an effective method to improve soil quality. In order to determine the effects of catch crops on soil characteristics and the growth of afterculture vegetables, onion, corn, wheat, soybean and cabbage were planted as catch crops for two years during the summer fallow season, with no catch crop as CK. The results showed that the total porosity and organic matter content of the soil, with corn and wheat as catch crops, was significantly increased by 2.93%, 5.25% and 21.32%, 51.61%, respectively, while pH was decreased, compared with CK. The urease, sucrase, invertase, catalase and FDA enzyme activity of the soil with corn and wheat as catch crops was significantly increased by 30.14% and 30.21%, 14.81% and 25.31%, 15.43% and 15.21%, 29.37% and 28.69%, 46.32% and 44.23%. Meanwhile, the enzyme activity of the soil was increased with each catch crop planted. The amount of culturable bacteria and actinomycetes in the soil with corn and wheat as catch crops was increased by 33.42% and 38.12% at the period of 150dayII, while fungi was decreased by 59.95%. The yield of vegetables with corn and wheat as catch crops significantly increased by 5.59~13.33% and 4.35~11.18% compared with CK. Overall, catch crops could improve the soil quality as well as the growth of afterculture vegetables.