刈割频率对无芒雀麦、苜蓿混播草层产量竞争及翌年叶片功能的影响

试验以草原3号杂花苜蓿和无芒雀麦为试验材料,对2年生混播牧草进行刈割处理,通过对两种牧草产量及翌年头茬牧草净光合速率测定结果表明:首次刈割时间推后,无芒雀麦的竞争力下降,产量降低.年刈割频率降低无芒雀麦竞争力增大,而抑制苜蓿的竞争力;刈后翌年头茬苜蓿叶片的光合速率、气孔导度、蒸腾速率随上一年刈割频率升高逐渐下降,而无芒雀麦随刈割频率的升高呈逐渐增加的趋势,说明低频刈割翌年苜蓿地上部分具有竞争优势,而高频刈割增强了无芒雀麦的种群竞争力.

Effect of Mowing Frequency on Yield Competition and Leaf Function of Mix-sowing Grassland of Bromus inermis and Alfalfa

Two-year grass Caoyuan NO. 3 alfalfa and bromus inermis were used as the experiment materials,and two pasturages were treated to mow. By analyzing yield and net photosynthetic rate of head stubble of the next year,the results showed that the competition of bromus inermis decreased and yield reduced with pushing the first mowing time. Reducing the year mowing frequency could increase the competition of bromus inermis,but restrain the competition of alfalfa. The net photosynthetic rate.leaf stomata conductance and transpiration rate of head stubble alfalfa gradually reduced after mowing in the next year, with last year mowing frequency increased, and net photosynthetic rate, leaf stomata conductance and transpiration rate of bromus inermis gradually increased with increasing mowing frequency. The results showed that next-year alfalfa had competition advantage with low mowing frequency in growth course,and next-year bromus inermis had competition advantage with high mowing frequency in growth course.