Alternative Management Systems of Beef Cattle Manure for Reducing Nitrogen Loadings: A Case-Study Approach.

Yubin Wang,Qian Li,Jingjing Wang,Renjie Dong,Suraj Ghimire

doi:10.3390/ani11020574

Abstract

Simple SummaryLivestock manure is one of the primary sources of agricultural nonpoint source pollution and poses a great threat to the environment and human health. Sustainable management of manure via recycling is an effective means to tackle the problem. Based on field interviews in China, four alternative manure management systems were investigated: Compost-based systems, product-based systems, substrate-based systems, and biogas-based systems. For each system, the reasons of emergence, success factors, risk factors, operation mechanism, scalability, key elements, and environmental effects were discussed. Results showed that the adoption of a system is driven by various factors and market-oriented operation is the dominant operation mechanism of all the manure management systems. Compared to direct application of manure to croplands, all the manure management systems can reduce nitrogen loadings from livestock farms and lower their environmental effects. Specifically, biogas-based systems can reduce nitrogen loadings to the greatest extent, followed by product-based systems and substrate-based systems, and then by compost-based systems. Integrated management of manure with mixed recycling systems is imperative for reducing its environmental effects, which can benefit from the increasing role of third-party entities in manure recycling. Policy implications were also discussed.Livestock manure is one of the main sources of agricultural nonpoint source pollution and poses a great threat to the environment and human health. Sustainable management of manure via recycling is an effective means to tackle the problem. Based on field interviews in China, multiple case studies were employed to investigate alternative manure management systems. Four conclusions arose. First, compost-based systems, product-based systems, substrate-based systems, and biogas-based systems were identified as four main types of manure management systems, with each possessing its success factors and risk factors. The adoption of a system was driven by various factors. Second, market-oriented operation was the dominant operation mechanism of all the manure management systems. Third, compared to direct application of manure to croplands, all the four manure management systems could reduce nitrogen loadings from livestock farms and lower their environmental effects. Among the systems, biogas-based systems could reduce nitrogen loadings to the greatest extent, followed by product-based systems and substrate-based systems, and then by compost-based systems. Lastly, integrated management of manure with mixed recycling systems is imperative for reducing its environmental effects, which can benefit from the increasing role of third-party entities in manure recycling. Policy implications were also discussed.

Highlights

With the improvement of human living standards and changes in human diet structure, the livestock sector has proliferated worldwide, leading to considerable environmental pollution caused by livestock manure [1]
A cross-system comparison was conducted to explore the reasons of emergence, success factors, risk factors, operation mechanism, scalability, key elements, and environmental effects of the four alternative management systems of beef cattle manure
With the ongoing trend of intensification and consolidation of livestock farming [88], integrated management of manure with mixed recycling systems is imperative for reducing its environmental effects

Summary

Introduction

With the improvement of human living standards and changes in human diet structure, the livestock sector has proliferated worldwide, leading to considerable environmental pollution caused by livestock manure [1]. Since the beginning of the 21st century, over 30 million tons of livestock manure (N content) have been produced worldwide annually, a number that keeps growing [2]. In the last three decades, China has experienced a substantial transformation in its livestock industry, making it the world’s largest producer and consumer of livestock products. This has profoundly affected its domestic and global food provision, resource use, nitrogen and phosphorus cycles, and greenhouse gas emissions [7]. China is the world’s leading livestock manure generator, producing about 18.22% of the world’s livestock manure (N content) in 2017 [2]. In 2017, 959.36 million tons of manure was generated in China, of which Inner

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