The Effects Of Fertilizer And Water Additions On Main Plants N Absorption And Utilization Stand In Kobresia Humilis Meadow Based On¹⁵N Isotope Labeled

This experiment was to study the effects of fertilizer and water addition on Eachorgan of typical alpine meadow plants N utilization rate based on15N isotope labeledin Haibei Station of Qinghai Province, comparison of intraspecific and interspecific(or functional groups) variation of nitrogen utilization rate. Nine treatments wereestimated installed, i.e., contrast (CK), increased rain in summer (W1), increasedsnow in winter (W2), applied N fertilizer (N), N fertilizer application and increasedrain together in summer (NW1), applied N fertilizer and increased winter snowtogether (NW2), applied P fertilizer (P), P fertilizer application and increased raintogether in summer (PW1), applied P fertilizer and increased winter snow together(PW2). Plants were installed, i.e., Elymus nutans Griseb, Kobresia humilis,Gueldenstaedtia diversiffolia, Potentilla sp.15N isotope labeled, the15N abundanceand biomass accumulation were affected by species N utilization rate, and highnitrogen utilization rate resulted in high15N concentration and biomass accumulation.So in this article, the differences of various species organ15N abundance and biomassaccumulation was analyzed and compared. The experimental results are as follows:(1) In the addition of applied fertilization or binding water and fertilization, thebiomass accumulation was the largest. P fertilizer or binding water and P fertilizerwas propitious to belowground biomass allocation of E. nutans, K. humilis andPotentilla sp., and N fertilizer or binding water and fertilizer was propitious toaboveground biomass allocation. But G. diversiffolia was difference, and applied Nfertilizer was propitious to belowground biomass, and applied N fertilizer waspropitious to belowground biomass.(2) The abundance of Nitrogen was increased by transporting from the root andstem to leaf and fruit.15N concentration in leaf and fruit was higher than that of rootand stem. Binding fertilization and water was propitious to each organ of species15Nabundance. Especially, the15N abundance of G. diversiffolia is highly enriched inwater and N fertilizer binding.(3) In the addition of N fertilizer or water and N fertilizer interaction, nitrogenutilization rate of these species was higher. Utilization nitrogen rate had littlevariation on these species in the addition of P fertilizer or water and P fertilizerinteraction, even sometimes played an inhibitory role (such as K. humilis). Nitrogenutilization rate of Potentilla sp.was not higher in water and fertilizer treatment.(4) The E. nutans aboveground nitrogen utilization rate was higher than that of K.humilis. The organ of G. diversiffolia and Potentilla sp.had the lower nitrogenutilization rate.