Abstract: Grey system decision-making method is used to make optimization sequence of intercropping combinations for the agroforestry of young Taxodium ascendens stands in Lixia river basin of Jiangsu province. The rape-water melon-vegetable combination is selected as the optimum and then is the rape-soybean combination. Several other designs are also suggested, which are economically rational and actually practicible for reference in production.

Key words: wheat/maize/soybean relay strip intercropping, soil nitrogen content, soil enzyme activity, nitrogen transformation