摘要 : Ten dairy farms participated in an EU project that aimed to improve nitrogen use and assist with the adoption of more environmentally friendly farming practices. Nitrogen use and management decisions were monitored during 2003, 20... 展开 Ten dairy farms participated in an EU project that aimed to improve nitrogen use and assist with the adoption of more environmentally friendly farming practices. Nitrogen use and management decisions were monitored during 2003, 2004 and 2005. Nine farms improved nitrogen use (nitrogen output relative to input) in Year 2. Four farms maintained or further improved nitrogen use in Year 3. Management decisions and external factors that improved nitrogen use were increasing farm milk output, adopting best management practices for nitrogen use, growing forage crops that required less nitrogen than grass and favourable crop production conditions that rendered large quantities of good quality forage. Decisions that worsened nitrogen use were increasing cow numbers without sufficient management support, the late start of supplementary feeding when grass quality declined, setting the target yield too high, pursuing a higher milk price, less palatable silage and disease. Sufficient slurry storage is essential to improving nitrogen use. The savings from lower nitrogen input and the revenue from milk were in no proportion to the investments required for additional slurry storage, however. The farmers did adopt environmentally friendly practices, but only to the degree their businesses were able to sustain. 收起