Abstract:

To address the dual challenges of soil degradation caused by long-term chemical fertilizer application in citrus orchards and livestock and poultry waste pollution, this study systematically reviews the biological configuration technologies of grass cultivation in citrus orchards, the assimilation potential of aquaculture waste, and the ecological and productive effects, aiming to construct an " citrus-grass-livestock" ecological recycling model and achieve resource utilization of agricultural waste. The results indicate that: (1) suitable grass species for citrus intercropping should be adapted according to tree age and season; young orchards are suitable for light-loving and high-yield forage grasses (e.g., peanut, ryegrass), while mature orchards prioritize shade-tolerant and dwarf forage grasses (e.g., white clover, bahiagrass); spatiotemporal configuration requires optimization of sowing dates and mowing frequency (ryegrass is suitable for autumn sowing, with 3-4 mowings annually). (2) Significant differences exist in nutrient requirements between citrus and forage grasses; citrus orchards of varying yields can assimilate cattle manure at 9.62-24.04 t/hm² and pig manure at 6.58-16.45 t/hm², while ryegrass demonstrates assimilation capacities of 9.21 t/hm² for pig manure and 13.4 t/hm² for cattle manure. (3) This model significantly improves soil properties (reducing bulk density by 17.26% and increasing organic matter by 39.6%), promotes growth of both citrus and forage grasses, with maximum citrus yield increase of 19.5%, and elevates fruit soluble solids content from 101.1 g/kg to 108.7 g/kg (a 7.6% improvement). In conclusion, the citrus grass cultivation model, through scientific biological configuration, efficiently assimilates livestock waste while simultaneously achieving soil improvement and yield-quality enhancement, representing a circular agriculture model that balances ecological and economic benefits. This study provides theoretical support for the promotion of the "citrus-grass-livestock" model; future research should focus on regional adaptability, long-term application risks, and the establishment of technical standards.

Key words: citrus grass cultivation, livestock waste assimilation capacity, forage spatial-temporal arrangement, nutrient demand traits, soil improvement, crop yield and quality