刈割和施氮对旱雀麦生长繁殖的影响OA

To reasonably utilize the resources of Bromus tectorum in the Junggar Desert,this study conducted a pot experiment exploring the effects of clipping intensity and nitrogen addition on its growth and reproduction.Three clipping intensities as well as nitrogen addition levels were established,respectively:no clipping(A0),stub-ble height of 7.6 cm(A1),and stubble height of 2.5 cm(A2);along with 0(N0),20(N1),and 40(N2)g·m-2·a-1.The results showed that clipping and nitrogen application significantly extend the growth period and accelerate re-growth of B.tectorum.Under clipping alone,A1N0 extended the growth period by 7 days,and A2N0 accelerated regrowth by 17%;after nitrogen application,A1N1 extended the growth period by 14 days and increased the re-growth rate by 67%.Clipping had no significant effect on growth parameters(P>0.05),whereas nitrogen applica-tion significantly affected plant height,flag leaf length and width,and leaf area(P<0.01).Under the same clip-ping intensity,total biomass increased significantly with increasing nitrogen application rates,with both aboveg-round and belowground biomass showing marked enhancements compared to the control treatment(A0N0).Spe-cifically,the A1N2 treatment elicited significant increases in aboveground and belowground biomass,resulting in a total biomass of 10.28 g.Under the same clipping intensity,seed number and seed weight increased with nitro-gen application rate.Without nitrogen application,A2N0 was greater than A0N0,whereas at nitrogen levels N1 and N2,the A0 treatment was slightly superior to A2.Clipping increased the number of seeds,seed weight,and biomass,with a compensation index greater than 1.Furthermore,nitrogen application enhanced the overcompen-sation growth pattern.Studies indicate that B.tectorum can be used as an early-spring forage for rational grazing,and the optimal treatment for improving its growth and reproduction is 40 g·m-2·a-1.at a 7.6 cm stubble height.