断根对紫花苜蓿产量及根系形态的影响

Effect of tilling on yield and root morphology of alfalfa

【目的】解决紫花苜蓿(Medicago sativa)种植3~5年后,产量和品质下降的问题,延长紫花苜蓿利用年限。【方法】对种植4年的紫花苜蓿进行20~25 cm土层断根处理,研究断根后其产量、根系及土壤的变化。【结果】1)断根处理当年的紫花苜蓿株高增加18%,分枝数增加了20个/株,草产量增加了33.8%;2)断根处理使0~30 cm土层紫花苜蓿根生物量增加了54.5%,根长增加了8%,根表面积增加了24.6%,根体积增加了79.4%;3)断根处理降低了0~20 cm土层土壤容重和0~30 cm土层土壤紧实度(P<0.05)。【结论】断根技术可用于内蒙古中东部及东北种植多年的紫花苜蓿田,是这些区域维持紫花苜蓿高产、延长紫花苜蓿利用年限的一种有效方法。

【Objective】Yield and quality of alfalfa(Medicago sativa L.)decreased with the increase in cultivating years of 3~5.This study was to solve these problems and prolong the utilization of alfalfa.【Method】The yield,roots and soil condition of 4‐year old alfalfa were studied with tilled roots by 20~25 cm.【Result】The results showed that:1)The height was increased by 18%,the number of branches was increased by 20 branches per plant,and the grass yield was increased by 33.8%in first year;2)The root biomass was increased by 54.5%,the root length was increased by 8%,and the root surface area was increased by 24.6%,the root volume was increased by 79.4%;3)The volume weight of 0~20 cm soil layer and soil compaction of 0~30 cm soil layer was reduced(P<0.05).【Conclusion】Tilling technology can be used in alfalfa fields in central and eastern of Inner Mongolia and northeast China.Tilling is an effective method to maintain yield and pnnyrolong the utilization years of alfalfa in these areas.