Effects of Nitrogen,Phosphorus and Fungicide Additions on Net Primary Productivity in Desert Steppe
An in-situ experiment was conducted to evaluate the effects of nitrogen(N),phosphorus(P),and fungicide application on net primary productivity(NPP)in desert steppe in eastern Ningxia,China.The results showed that N,P and fungicide addition significantly increased aboveground net primary productivity(ANPP),belowground net primary productivity(BNPP),and NPP(P<0.01).P and fungi-cide additions displayed antagonistic effects on ANPP and NPP.Fungicide had minimal effects on control plots but significantly increased ANPP and NPP in P addition plots(P<0.01).No significant interactive effects of N and P on any NPP measures were observed.N addition significantly increased BNPP in the 10-30 cm soil layer(P<0.01),while P addition significantly promoted BNPP across all three soil depths(0-10 cm,10-30 cm and 30-40 cm).In P addition plots,fungicide significantly increased shoot biomass of deep-rooted plants(P<0.01).The relative biomass of deep-rooted plants positively correlated with BNPP(P<0.01).This findings suggested that P addition promoted BNPP by enhancing the relative bio-mass of deep-rooted plants.Overall,this study demonstrated that N,P,and fungicide additions all influ-enced NPP in eastern Ningxia desert steppe,with P addition having the strongest effect.
NETL
NSTL
万方数据
