[Nitrogen balance in dairy farm: research progress].

Area of Science:

• Environmental Science
• Agricultural Science
• Animal Science

Background:

• Intensive dairy farming practices, characterized by high stocking densities, often result in nitrogen discharges exceeding environmental carrying capacities.
• Dairy farms are significant contributors to agricultural nitrogen pollution, necessitating a focus on nitrogen balance and cycling.
• Understanding nitrogen flow is crucial for effective dairy farm management, environmental policy development, and sustainable agricultural practices.

Purpose of the Study:

• To introduce the concept of farm-scale nitrogen balance and nitrogen flow within dairy operations.
• To compare the utility of nitrogen surplus and nitrogen use efficiency as key indicators for evaluating nitrogen management.
• To analyze factors influencing nitrogen balance in dairy farms and propose strategies for reducing nitrogen discharges.

Main Methods:

• Review and conceptualization of nitrogen balance and flow on dairy farms.
• Comparative analysis of nitrogen surplus and nitrogen use efficiency metrics.
• Identification and summarization of factors affecting nitrogen balance and mitigation strategies.

Main Results:

• Nitrogen balance on a farm scale is a critical metric for assessing environmental impact.
• Nitrogen surplus and nitrogen use efficiency provide reliable indicators for evaluating nitrogen management effectiveness.
• Various factors, including stocking density and waste management, significantly influence nitrogen balance.

Conclusions:

• Effective nitrogen management in dairy farms is essential to mitigate environmental pollution.
• Implementing strategies to reduce nitrogen discharges is vital for sustainable dairy farming in China.
• Further research and policy development are needed to optimize nitrogen cycling and minimize environmental impact from dairy operations.