Journal of Northern Agriculture ›› 2022, Vol. 50 ›› Issue (6): 63-71.doi: 10.12190/j.issn.2096-1197.2022.06.09

• Soil and fertilizer·Prataculture • Previous Articles     Next Articles

Influence of nitrogen addition on the productivity of desert steppe under different grazing intensities

JIN Zhengliang1,2,3, FAN Wentao2,4, ZHANG Pujin1, ZHANG Guolong2, CHU Wenbin5, WU Dianjun6, Qinggele 1   

  1. 1. Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences,Hohhot 010031,China
    2. School of Ecology and Environment,Inner Mongolia University,Hohhot 010020,China
    3. Chengkou County Bureau of Water Resources,Chongqing 405900,China
    4. Hohhot Service Center of Environment and Sanitation,Hohhot 010020,China
    5. Liangcheng County Bureau of Agricultural,Animal Husbandry and Science and Technology,Liangcheng 013750,China
    6. Hohhot Science and Technology Extension Center of Ecology and Environment,Hohhot 010090,China
  • Received:2022-06-24 Online:2022-12-20 Published:2023-03-24
  • Contact: ZHANG Pujin

Abstract:

【Objective】To study the influence of nitrogen addition on the productivity of desert steppe under different grazing intensities and to propose effective measures to increase the productivity of desert steppe under different grazing backgrounds.【Methods】In Siziwang Banner,Inner Mongolia,nitrogen addition were conducted on desert steppe that had undergone various grazing intensities with addition levels of 0(CK),7,14 and 21 g/(m2·a). The effects of historical grazing intensities and years on plant biomass as well as the effects of nitrogen addition on biomass of various functional groups were analyzed. 【Results】Plant community biomass decreased as grazing intensity increased in the drought years,and was highest under moderate grazing in the rainy years. Nitrogen addition promoted the increase of above ground biomass of plant community under light grazing and moderate grazing,with increases of 10%-65% and 15%-35% respectively. Nitrogen addition in the rainy years increased the biomass of perennial bunch grasses under heavy grazing by 13%-23%. The optimum amount of nitrogen addition in the three-year experiment was 7,14 and 21 g/(m2·a) under light grazing,14,14 and 7 g/(m2·a) under moderate grazing,and 21 g/(m2·a) in the first year,with no addition in the following two years under heavy grazing.【Conclusion】Nitrogen addition promoted the increase of plant community biomass under light and moderate grazing. The optimum amount of nitrogen addition to promote the plant community biomass recovery was different under different grazing backgrounds,this relates to community species composition and annual precipitation.

Key words: Nitrogen addition, Grazing intensity, Desert steppe, Productivity

CLC Number: 

  • S812