| In order to deal with grassland degradation problems of semi-arid farming-pastoral zone in Inner Mongolia, which is caused by excessive use and lack of necessary cultivation measures, we carried out three fertilization measures, such as chemical and organic single fertilizations, NPK combined applications and compound bio-fertilizations. Chemical fertilization was of nitrogen and phosphorus combined fertilization(N, P2O5), organic fertilization was of local purchased sheep dung, then chose three kinds of different fertilization rate of each of them to do experiment; To exert "3414" design to process NPK experiment, that was combination the nitrogen(urea 46%, N), phosphate(calcium superphosphate, 12% P2O5) and potash fertilization(potassium sulphate 51%, K2O) with three levels in different ways to conduct the experiment. The compound bio-fertilization of third experiment was Humic acid, molasses fermentation and alginate compound bio-fertilization, include three fertilization mixed adopted to conduct experiment. To measure the grass yield, soil physical and chemical properties and the change of the community features under different processing, respectively. The results were as follows:(1) On chemical and organic fertilization experiment, the total aboveground biomass increased significantly in RC1(260.66 g/m2)compared to the control(P < 0.05); On NPK combined fertilization experiment, the above-ground biomass of L. chinensis increased significantly by 235.66% and 235.66% in N2P1K1 and N2P3K2(133.63 g/m2 and 129.01 g/m2) compared with the control, respectively. The total aboveground biomass in N2P2K2, N2P1K1, N2P0K2 and N2P3K2 are high significant than control(P < 0.05); In compound bio-fertilization experiment, alginate made l. chinensis production increased significantly compared to the control(p < 0.05).(2) The influence of chemical and organic fertilization on soil physical and chemical properties was mainly manifested in the change of soil organic matter, such as, the organic matter in RO3 show the significance of difference both in the 0-10 and 10-20 cm soil layer; On NPK combined fertilization experiment, only conductivity, total nitrogen and total potassium had significant changes; the application of bio-fertilization can increase the soil organic matter, and molasses fermentation can cause the reduction of total phosphorus in surface soil layer.(3) The l. chinensis had been always in a dominant position among three of different measure. Chemical and organic fertilization experiment had no significant impact on the α diversity indexes(P > 0.05); On NPK combined fertilization experiment, Margalef abundance index(Dma) increased significantly in N0P2K2 compared with the N2P2K0, N2P2K3 and N3P2K2(P < 0.05), while significantly reduced in N3P2K2 compared to the N0P2K2 and N2P1K1(P < 0.05); Compound bio-fertilization experiment let the Simpson dominance index(C) decreased significantly in alginate and three fertilization mixed treatment compared to the others(P < 0.05). |
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