不同氮磷施量对河西走廊紫花首蓿产量和品质的影响

打开文本图片集

中图分类号：S541.9 文献标识码：A 文章编号：1007-0435（2025）05-1486-11

Abstract：To investigate the efects of diferent fertilization treatments on the production performance and qualityof alfalfa （Medicago satia L.），a two-year field experiment was conducted in the irrigated decertified area of the Hexi Corridor，Gansu Province，with two nitrogen （N） application levels （O and 103.5kg⋅hm-2. ）and four phosphorus （P2O5 gradients（0，45，90，and 135kg⋅hm-2; .The results demonstrated that combined nitrogen-phosphorus fertilization significantly enhanced alfalfa yield and quality. The optimal treatment （N1P2 N103.5kg⋅hm-2 ， P2O590kg⋅hm-2） achieved a hay yield of equivalent to 16.64t⋅hm-2 ，representing a 26.41% increase compared to the control. Additionally，in comparison with the control，this treatment elevated crude protein（CP）content by 14.3% to 19.8% and improved the relative feed value（RFV）by 11. 2% ，while maintaining acid detergent fiber（ADF）and neutral detergent fiber （NDF）at 32.5% and 41.7% ，respectively，approaching international standards for premium alfalfa. Structural equation modeling （SEM）revealed that nitrogen directly promoted CP accumulation by increasing internode number（path coefficient =0.24⋅ ，whereas phosphorus indirectly reduced fiber content by enhancing leaf area expansion （path coefficient ：=-0.17） .Economic analysis indicated that the N1P2 treatment yielded the highest net profit （39，791 yuan hm-2 ），exceeding the high-phosphorus treatment （N1P3） by 2.7% ，with phosphorus use efficiency reaching 42.6% . Based on these findings，we recommend fertilization rates of N103.5kg⋅hm-2 and for second-and third-year alfalfa cultivation in the Hexi Corridor.Furthermore，split nitrogenapplication combined with soil nutrient diagnostics is proposed to optimize nutrientutilization eficiency，which provides a scientific guidance for sustainable forage-livestock systems in arid regions.

Keywords：Medicagosatiua;Fertilization;Yield;Quality

紫花苜蓿（Medicagosatiua）为多年生豆科牧草[1]，适应性强，适口性好，蛋白质含量高[2-4]，促产奶性能明显，在畜牧业生产中发挥着极为重要的作用[5。（剩余13733字）