Effects of intercropping different leguminous green fertilizers on navel orange yield, quality, and basic soil fertility

Using a field plot experiment method, the effects of intercropping three leguminous green fertilizer varieties (i.e., Chamaecrista rotundifolia (Pers.) Greene, Vigna sesquipedalis, and Indigofera hendecaphylla Jacq.) on the fruit appearance, nutritional quality, soil erosion in the topsoil layer, and basic fertility of the navel orange orchard were studied, with no intercropping green fertilizer treatment as a control. The results showed that intercropping those three green fertilizer varieties in the navel orange orchard, compared to the control treatment, the vertical diameter of navel orange fruit increased by 3.34%~11.35%, the horizontal diameter increased by 3.05%~7.46%, the single fruit weight increased by 2.45%~28.15%, and the yield increased by 6.85%~19.94%; Increasing the water-soluble total sugar content of the fruit by 19.93%~ 41.09%; The loss thickness of the surface soil of the orchard can be reduced by 0.9cm, 1.0cm, and 1.1cm, with a reduction rate of 30.6%, 27.8%, and 25.0%, respectively; Improve the organic matter of the surface soil of the orchard by 86.7%~214.9%, total nitrogen by 100.0%~238.7%, total phosphorus by 50.0%~450.0%, alkali hydrolyzed nitrogen by 90.8%~145.3%, available phosphorus by 18.4%~571.1%, and available potassium by 94.9%~205.1%. Among them, intercropping Vigna sesquipedalis treatment has a relatively better effect on improving the basic fertility of the surface soil of the navel orange orchard.