关键词: 植被覆盖, 土壤养分, 风蚀, 甘草

Abstract:

To explore effects and mechanisms of liqorice (Glycyrrhiza Uralensis) vegetation conserving soil nutrients and reducing wind erosion, analysis was done of the liqorice vegetation cover for characteristic indices and of the soil 0-5 cm under the cover for soil nutrient conservation and effect on wind erosion reduction. Results show that with the liqorice vegetation growing on, coverage, height and above ground biomass of the vegetation, and organic carbon(OC), available N, P and K contents in the topsoil all increased, while wind erosion and bulk density decreased (P<0.05). Correlation analysis indicates that characteristic indices were significantly and positively related to soil nutrients (P<0.05), showing an order of vegetation coverage> height> aboveground biomass in terms of correlation coefficient. Regression analysis demonstrates that for every 1% of increase in vegetation coverage, the content of OC, available N, P and K in the topsoil increased 0.038 g·kg^-1, 0.052 mg·kg^-1, 0.113 mg·kg^-1 and 0.971 mg·kg^-1, respectively. Obviously, the adoption of the practice of maintaining vegetation coverage on farmlands of wind erosion stricken regions of Northwest China, may on the one hand, reduce wind erosion of the surface soil and hence the loss of soil nutrients, and on the other hand, increase the amount of litters and hence content of soil nutrient, of which the joint effects will eventually reduce the loss of soil nutrients correspondingly.

Key words: vegetation coverage, soil nutrient, erosion, liqorice (Glycyrrhiza uralensis)