A 21-year experiment showed the combined fertilization was better than the single fertilization in fertilizer supply. The combined fertilization of organic fertilizers and nitrogenous chemical fertilizers showed the best performance with an interactive value of 1.33 and its yield-increasing effect was more than the single fertilization of either of the two. The combined fertilization of organic and phosphorous fertilizers had a interactive value of 0.90 and increased crop yields by 19.3% on average compared with the single fertilization of the two; the combined fertilization of organic and potassium fertilizers had an interactive value of 0.57 and increased crop yields by 8.4% compared with their single fertilization; in the combined fertilization of organic fertilizers and nitrogen fertilizers, the residual nitrogen rate ranged between 26.5% and 35.1% and the total nitrogen and available nitrogen increases respectively by 9.3%～73.3% and (10.1%)～46.9% compared with those in their single fertilization; in the combined fertilization of organic and phosphorous fertilizers , the residual phosphorous rate ranged between 68.3% and 69.7% and the total phosphorous and available phosphorous increased by 5.3%～26.6% and 200%～207% compared with those in their single fertilization; in the combined fertilization of organic and potassium fertilizers, the shortage of soil potassium decreased by 28.8%～78.5% and the available potassium increased by (84.6%～)128% compared with those in their single fertilization. In the combined fertilization, the soil organic matter increased by 41.8%～56.8%.