猪–沼–草–鱼循环模式下沼液种草养鱼及鱼类提质增值技术综述

Review on Technologies of Forage Cultivation and Fish Culture Using Biogas Slurry and Fish Quality Improvement in Pig-Biogas-Grass-Fish Circular Model

摘要: 规模化生猪养殖粪污废水是我国南方农业面源污染重要来源。传统高密度全配合饲料养殖草鱼，普遍存在养殖成本高、鱼体脂肪过度沉积、肌肉质地松散、土腥味突出、产品同质化、市场附加值偏低等问题。猪–沼–草–鱼生态循环模式以沼气工程为枢纽，构建“生猪养殖–粪污厌氧发酵–沼液资源化种草–青绿牧草生态养鱼–成鱼瘦身提质增值”闭环产业链。本文基于现有公开文献，系统梳理该模式技术框架，归纳沼液无害化预处理、沼液水肥一体化牧草栽培、牧草生态养鱼、成鱼生态瘦身提质等关键工艺的已有研究结论；对比不同文献报道的生态、经济效果，辨析现有研究分歧与局限，剖析模式推广现实障碍，并提出未来研究方向。综合文献表明，规范化运行条件下，该循环体系具备削减化肥、饲料投入，改善草鱼肌肉品质，实现产品市场溢价的潜力，但各项效益受沼液预处理水平、牧草投喂比例、瘦身工艺参数等条件约束，并非普适最优方案，适宜在广东丘陵农牧区因地制宜开展推广实践。

Abstract: Large-scale pig breeding produces massive manure wastewater, which constitutes an important source of agricultural non-point-source pollution in South China. Conventional high-density grass carp culture totally relying on compound feed faces prominent drawbacks such as high production cost, excessive fat deposition, loose muscle texture, obvious earthy off-flavor, product homogenization and low market added-value. Centered on biogas projects, the pig-biogas-grass-fish circular model builds a closed-loop industrial chain of “pig breeding, anaerobic fermentation of livestock manure, forage cultivation with biogas slurry, grass-based ecological grass carp culture and quality improvement via pre-marketing fasting conditioning”. Based on published literatures, this review systematically sorts out its technical framework, summarizes existing research findings of key processes including harmless pretreatment of biogas slurry, integrated water-fertilizer forage cultivation, grass-fed aquaculture and fasting-induced quality improvement of grass carp. Differences and contradictions among previous studies are analyzed, practical bottlenecks are discussed, and further research directions are proposed. Synthesized from existing literature, standardized circular system shows potential to reduce chemical fertilizer and feed input and improve flesh quality with market premium. Nevertheless, its comprehensive benefits are strongly constrained by pretreatment quality of biogas slurry, forage feeding ratio and fasting parameters. This model is not universally applicable and should be popularized according to local conditions in hilly agricultural-pastoral regions of Guangdong Province.