Effects of NPK application on degraded grassland productivity and community structure on Bashang plateau" />
Bashang plateau, degraded grassland, fertilization test;,biomass,species diversity,"/>
氮磷钾配施对坝上退化草地生产力及群落特征的影响
In this research, the typical Leymus chinensis degraded grassland in Zhangbei Basin was taken as the research object, and the “3414” orthogonal test design was adopted. A three-factor and four-level fertilization experiment of nitrogen, phosphorus and potassium was set up to study the impact of fertilization gradient and the type of fertilization on the grassland productivity, community structure, species richness and diversity on the Bashang plateau. The results showed that the effects of nitrogen, phosphorus, and potassium fertilizers on grassland aboveground biomass were nitrogen fertilizer, phosphorus fertilizer, and potassium fertilizer in descending order. With the increase of fertilizer application, the grassland biomass showed a trend of increasing first and then decreasing. When they were all at the medium level (N2P2K2), the above-ground biomass of the grassland reaches the best at 289.43 g/m2 . Nitrogen and phosphorus fertilizers can signifificantly increase the grassland vegetation density, while potassium fertilizer has no signifificant effect on the vegetation density, and the grassland density with N2P2K2fertilization reached the highest of 748.67 plants/m2 . Nitrogen fertilizer also promotes the increase of grassland vegetation coverage, while phosphorus and potassium fertilizers have no signifificant effect on vegetation coverage. The grassland coverage of N3P2K2 fertilizer treatment reached a maximum of 80.00%. With the combination of N, P and K, the Simpson index, Shannon-Wiener index, and Pielou index of grassland vegetation diversity all decreased, while the species richness index did not change signifificantly.
2020, Vol. 43 
