The Impact Of Root-cutting And Fertilization On Plant Community In Mowing Pasture Of Leymus Chinensis Typical Steppe

As a feed storage depot for livestock in winter,the mowing pasture plays an important role in the animal husbandry development.The degradation and improvement of grassland is one of the focal points of the current research on grassland ecology.In order to explore the effect of root-cutting and fertilization on mowing pasture improvement in typical steppe,the experiment was conducted in the mowing pasture of MaoDeng ranch characterized by Leymus chinensis grassland in Xilinhot,Inner Mongolia,China.The different concentration gradients addition of nitrogen(N)and phosphorus(P)was performed on the basis of root-cutting and without root-cutting.In the present study,the characteristics of plant community and soil physical and chemical characteristics were compared and analyzed to provide theoretical guidance and reference for the degraded grassland improvement.,The main results are as follows:1.The above-ground biomass increased significantly by 56.63%in the RC3(root-cutting +N 12.6g/m2 + P 2.7g/m2)compared with the control(P<0.05),and the above-ground biomass of Leymus chinensis of the RC2(Root-cutting +N 8.4g/m'+P 1.8g/m2)was significantly higher than that of the control group,with a observably increase of 80.32%(P<0.05).2.Both the root-cutting and fertilization increased the population density and the biomass of Leymus chinensis.The fertilization also reduced the stem-leaf ratio of Leymus chinensis yet enhanced the photosynthesis.However,the stem-leaf ratio increased in the mixed treatment of root-cutting and fertilization.3.When the climate was wetter,the root-cutting could evidently increase the above-ground biomass of both the community and the population of Leymus chinensis(P<0.05),and the fertilization could evidently increase the above-ground biomass of Leymus chinensis(P<0.05).In contrast,the effect was not remarkable when the precipitation was scarce(P>0.05).In addition,there was no remarkable interaction of root-cutting and fertilization on the above-ground biomass of both the community and the population of Leymus chinensis between two years(P>0.05).4.In a short term,the different treatments had no effect on soil physical and chemical properties(P>0.05).5.The production and economic benefits of the RC2 treatment were increased 813.7 kg/hm2 and 233.7 yuan/hm2.In summary,Taking into consideration various factors,such as ecological,productive and economic benefits,the treatment of Root-cutting +N 8.4g/m2+P 1.8g/m2 is the best choice for improving the mowing pasture of Leymus chinensis when the climate was wetter.