Abstract:

In order to explore the improvement effect of different crop rotation on soil secondary salinization, the soil improvement effect and the effect on the growth of later vegetables under three different irrigation and drought rotation modes were compared with the vegetable continuous cropping mode. The results showed that the salt content of secondary salinized soil decreased significantly after the rotation treatment which decreased by 29.3% in the whole soil layer and 56.6% in the surface soil. The pH value of soil was increased, while the contents of organic matter, available phosphorus and available potassium were decreased. The content of available phosphorus was decreased by 31.8%. These improvements were helpful to promote the growth of later crops. Compared with the three irrigation and drought rotation modes, the soil salt washing effect of vegetable-rice rotation was better and the salt of the whole soil layer and soil surface decreased by 31.0% and 57.9%, respectively. The growth promotion effect of the later vegetables was better with an average increase of 8.2%. The soil of vegetable-lotus root rotation had the best acid reduction effect, and its pH of surface soil increased by 0.48 units. However, the soil of vegetable-wild rice stem rotation had better phosphorus reduction effect, the surface soil available phosphorus content decreased by 44.4%. Implementing water and dryland rotation in facility vegetables can effectively alleviate the degree of secondary soil salinization and continuous cropping obstacles. And it can promote farmers' income growth and agricultural efficiency improvement.

Key words: facility cultivation, water and drought rotation, soil salinity, nutrient content, vegetable growth