Effects of maize as a catch crop on subsequent garland chrysanthemum and green soybean production in soil with excess nitrogen

摘要

Greenhouse vegetable cultivation is often associated with the rapid accumulation of nitrate in soils. Therefore, N management strategies are needed for greenhouse vegetable production systems. The objective of the present study was to evaluate the effects of a summer catch crop on vegetable crop yields. Maize, as an N catch crop, was planted in leafy vegetable (garland chrysanthemum) and fruit vegetable (green soybean) greenhouse cropping systems during the summer of two consecutive years. Maize removed 4.9-11.8 g N m(-2) from the greenhouse soil and also improved soil penetration resistance. The first year cultivation of maize increased the yield of garland chrysanthemum leaves but not the yield of green soybean. In first year, the yield of garland chrysanthemum showed negative correlation with SPAD value and nitrate content in leaves, while the yield of green soybean was positively correlated with shoot fresh weight and dry weights of roots and nodules. During the second year, cultivation of the catch crop clearly increased the yield of both garland chrysanthemum and green soybean. Positive correlations were observed between yield and SPAD value in garland chrysanthemum, and between yield and nodule dry weight in green soybean, respectively. These results indicate that using maize as a catch crop in soil with excessive N accumulation can improve soil conditions and promote subsequent crop growth. However, the effect of catch crop cultivation on yield was dependent on the type of subsequent crop.