Abstract: 【Objective】The research was conducted to explore the responsive mechanism of wheat yield stability to long-term fertilization. 【Method】 Based on long-term fertilization experiment in Yangliu village of Anhui province, the trend of change in wheat average yield, annual fluctuation of wheat yield and soil nutrients content in 5 fertilization patterns were investigated: non-fertilization (CK), application of single chemical fertilizer (NPK), application of single organic fertilizer (M), mixed application of organic and chemical fertilizer with the same amount of nitrogen (MNPK), mixed application of organic and chemical fertilizer with the larger amount of nitrogen (HMNPK).【Result】It was discovered that wheat yield in CK showed a declining trend by 5.81 kg•hm-2•a-1, while fluctuated increasing emerged in fertilization treatments. Wheat yield trend line of HMNPK was in the first place, but MPK had been chasing after by 9.75 kg•hm-2•a-1. Wheat yield trend line of NPK was higher than M in the earlier stage of experiment, whereas it was caught up by M after 22 years. In respect of wheat average yield of 32 years, HMNPK and MNPK were higher than other fertilization treatments, with 5 544.3 kg•hm-2 and 5 200.6 kg•hm-2, respectively; NPK took the third place, by increasing 614.6% of that in the non-fertilization treatment; wheat yield increasing of M was the lowest, however, no obvious difference was found between M and NPK. The contribution of soil capacity in lime concretion black soil had been decreasing in early 10 years then stopped and kept stable at 10%; the contribution ratio of fertilizer had been increasing in early 10 years, and then maintained dynamic balance at the level of 80%-90%. It enhanced the coefficient of variation (CV) and reduced sustainable yield index (SYI) without fertilization, which made yield stability the worst; the wheat yield stability of HMNPK and MNPK was better than NPK which was better than M. Compared with CK, fertilizer application increased the content of total nitrogen, organic matter, available phosphorus and available potassium in soil. Addition of organic fertilizer intensified the content of soil total nitrogen and organic matter. Available phosphorus content was related to application of chemical fertilizer. Available potassium content was at the relatively higher level in M, but the differences with other fertilization treatments were not significant. The contents of total nitrogen, organic matter and available phosphorus were significantly positively correlated with yield in Huaibei lime concretion black soil (P＜0.01).【Conclusion】Fertilizer application increased wheat yield significantly in Huaibei. The yield of HMNPK and MNPK were at the higher level, but the yield gap between the two treatments was shortening with growing years. Wheat yield of NPK was higher than M in earlier stage of experiment, while it was caught up with M after 22 years. Compared with CK, mixed application of organic and chemical fertilizer conduced to enhance wheat yield stability and sustainability, NPK took the second place, M placed the last. Fertilization increased soil nutrient content: organic fertilizer enhanced organic matter, total nitrogen, while chemical fertilizer enhanced available phosphorus. Wheat yield correlated positively with total nitrogen, organic matter and available phosphorus significantly. In a word, mixed application of organic and chemical fertilizer is the best fertilization mode in Huaibei lime concretion black soil area, which made soil nutrient more balanced, wheat yield more stable and agricultural ecosystem quality better.

Key words: lime concretion black soil , long-term fertilization , yield stability , yield sustainability