5 July 2002

Nitrate action pitfalls

MEASURES to reduce nitrate leaching from slurry and manure can lead to higher levels of gaseous nitrogen losses, potentially eliminating any benefits.

Injecting slurry instead of broadcasting it can reduce ammonia losses by 44%, said ADAS researcher Rachel Thorman. "In addition, spreading slurry in November and March led to less ammonia loss than spreading in September.

"But there was an increase in nitrous oxide production, another form of nitrogen pollution. This pollution swapping means measures to reduce nitrate leaching in nitrogen vulnerable zones could increase other forms of nitrogen pollution."

Research at ADAS is now investigating ways to reduce overall nitrogen losses while maintaining crop yields, she added. &#42