Background and aims

Mowing is used as a management practice in tree-grass agroforestry, but the water relationships between trees and grasses have been divergent. Here, we aim to reveal the effect of mowing frequency on the interspecific water relationships.

Methods

Walnut (Juglans regia L.) was intercropped with alfalfa (Medicago sativa L.) from 2021 to 2022, and the responses of soil moisture, plant roots and moisture sources, water use efficiency (WUE) and water consumption to different mowing frequencies (once, twice and thrice) were investigated.

Results

The soil moisture did not respond significantly to the mowing frequency; mowing significantly increased the root length density of alfalfa in all soil layers, especially in the 0–20 cm layer; mowing twice and thrice affected the water sources of walnut and alfalfa, and it increased the proportion of walnut trees that used deep soil water (up to 64.60%) and the proportion of alfalfa that used surface soil water (up to 58.5%); The WUE of walnut did not respond significantly to mowing, while that of alfalfa did (the highest average WUE of 5.44 mmol C/mol H₂O was found when alfalfa was mowed twice, which increased by 4.42% over the WUE of the mowing once treatment (CK)); compared to CK, the total water consumption of the intercropping system was unchanged when mowed twice but increased significantly when mowed thrice.

Conclusion

In the early stages, the walnut-alfalfa intercropping system can be managed by mowing twice, which can improve the WUE of alfalfa and maintain soil moisture.

中文翻译：

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割草频率对核桃 (Juglans regia L.)-苜蓿 (Medicago sativa L.) 间作系统种间水分关系的影响

 背景和目标

割草被用作树草农林业的管理实践，但树木和草之间的水关系却有所不同。在这里，我们的目的是揭示割草频率对种间水分关系的影响。

 方法

2021-2022年核桃（Juglans regia L.）与苜蓿（Medicago sativa L.）间作，研究土壤湿度、植物根系和水分来源、水分利用效率（WUE）和耗水量对不同割草频率（一次）的响应。 ，两次和三次）进行了调查。

 结果

土壤湿度对割草频率的响应不显着；割草显着增加了各土层中苜蓿根长密度，尤其是0~20 cm土层；二、三次割草影响了核桃树和苜蓿的水源，增加了核桃树利用深层土壤水的比例（高达64.60%）和苜蓿利用表层土壤水的比例（高达58.5%）；核桃的WUE对割草反应不显着，而苜蓿则对割草反应显着（苜蓿割两次时平均WUE最高，为5.44 mmol C/mol H ₂ O，较割草两次增加了4.42%）。一次割草处理（CK）的WUE）；与CK相比，间作系统的总耗水量在两次割草时没有变化，但在三次割草时显着增加。

 结论

核桃-苜蓿间作系统前期可进行两次刈割管理，可提高苜蓿的WUE，保持土壤墒情。