[Objective] Effective improves the soil fertility of abandoned lands of mines in gully region of the Loess Plateau

suitable plant species and cropping pattern selection were researched in order to provide a scientific basis for optimizing allocation of resources and promoting the sustainable development of agriculture in this area.[Methods] The experiments were conducted at the Changwu agro-ecological experimental station of the Chinese Academy of Sciences on the Loess Plateau. In order to explore the soil nutrient content under different available nitrogen condition in the 0-10 cm and 10-20 cm

five species plants were choosed(Trifolium repens

Melilotus suaveolens

Amorpha fruticosa

Caragana korshinskii and Lolium perenne). The treatments included three fertilization conditions﹝Organic manure(sheep manure) was used with the amount of 30 000 kg/hm2 as the treatment of A. Straw was used with the amount of 9 000 kg/hm2 as the treatment of B. No fertilization was used as a control group﹞

to explore the effect of soil available nitrogen under the different cropping pattern of single and mixed condition.[Results] The content of the average nitrate nitrogen was 9.05 mg/kg in the soil under the cropping pattern of single

which was more than 0.44 mg/kg compared with cotrol. The content of average nitrate nitrogen was 9.02 mg/kg in the soil under the cropping pattern of mixed

which was 0.41 mg/kg more than the cotrol. Under the condition of non-fertilization

the effect of cropping pattern on soil improvement was the single better than the mixed. The content of average ammonium nitrogen was 4.49 mg/kg in the soil under the cropping pattern of single

which was 2.06 mg/kg less than the control. The content of average ammonium nitrogen was 7.06 mg/kg in the soil under the cropping pattern of mixed

which was 0.51 mg/kg more than the cotrol. The effect of cropping pattern on soil improvement was the single better than the mixed.[Conclusion] The effect of cropping pattern on soil improvement was the single better than the mixed under the condition of non-fertilization and straw-fertilization. The effect of cropping pattern on soil improvement was the mixed better than the single under the condition of organic-fertilization.