Strategies to reduce nutrient pollution from manure management in China

Abstract

As the demand for livestock products continues to increase in China, so too does the challenge of managing increasing quantities of manure. Urgent action is needed to control point source (housing, storage and processing) and diffuse (field application) pollution and improve the utilization of manure nutrients and organic matter. Here, we review strategies to improve management at each stage of the manure management chain and at different scales. Many strategies require infrastructure investment, e.g., for containment of all manure fractions. Engineering solutions are needed to develop advanced composting systems with lower environmental footprints and design more efficient nutrient stripping technologies. At the field-scale, there is an urgent need to develop a manure nutrient recommendation system that accounts for the range of manure types, cropping systems, soils and climates throughout China. At the regional scale, coordinated planning is necessary to promote recoupling of livestock and cropping systems, and reduce nutrient accumulation in regions with little available landbank, while minimizing the risk of pollution swapping from one region to another. A range of stakeholders are needed to support the step change and innovation required to improve manure management, reduce reliance on inorganic fertilizers, and generate new business opportunities.

Sustainable Development of Crop-Livestock Farms in Africa

“…These effects are caused by high livestock densities and widespread fertilizer use which lead to increased ammonia emissions, N deposition and nutrient losses to waterbodies. Similar trends are observed in China where the increasing demand of animal protein has led to the expansion of large-scale landless livestock operations in addition to small backyard mixed farms [9] . Both systems have poor manure management practices and this has led to the pollution of major rivers in China.…”

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

“…China faces a significant challenge in sustainable manure management [ 11 ], with worldwide attention drawn towards the country [ 12 ]. Developed countries with a trend towards concentrated animal feeding operations face similar challenges, such as the dairy industry’s manure management scenario in the United States [ 13 , 14 , 15 ].…”

“…Land application is still a major way to utilize livestock manure in developing countries [ 36 ], e.g., in South Africa, livestock manure is mostly left in the pasture or paddocks or managed as drylots [ 37 ]. Manure can be returned to land either directly or after composting and should be applied based on manure characteristics, soil types, and agronomic requirements of crops [ 11 ]. However, with the development of intensive animal farming and the specialization of livestock and crop production, the practice of returning manure directly to cropland is becoming more problematic.…”

Green Agriculture and Blue Water in China: Reintegrating Crop and Livestock Production for Clean Water

“…Methods such as soil injection (liquid manures) and broadcasting (solid manures) can help arable farmers to apply manures efficiently to avoid nutrient losses. Technologies improving animal feeds and reducing emissions from manure storage [52,53] are also effective and have the potential to reduce nutrient losses by up to 30% [54,55] . In crop production, farmers should avoid overfertilization and replace synthetic fertilizers with animal manures.…”