The Cabinet’s nitrogen measures could cut ammonia emissions on dairy farms by 25 to 30 per cent, says researcher Gerard Migchels of Wageningen Livestock Research.
The measures for diluting manure with water in barns and when muck spreading in particular will reduce ammonia emissions. Migchels’ colleagues are currently carrying out measurements to find out what the ammonia benefits are when spreading manure on sandy soil. Earlier research by Migchels himself on peat soil where one part water was added to two parts manure reduced ammonia by 40 per cent. He expects a reduction of 25 to 40 per cent on sandy soil.
This measure does require water, which could be a problem given the current dry conditions. Migchels therefore advises farmers to invest in water storage. ‘Each cow has 21 square metres of roof, which you can use to collect rainwater.’ The ministry of Agriculture is going to make money available for water storage in agriculture. The water is also needed for spraying the slurry grids in the shed, a measure for reducing ammonia emissions in barns.
The ministry also wants to restrict the amount of protein (nitrogen) allowed in feed so that less ammonia is produced. Migchels thinks this is a good idea but he is less impressed with the approach chosen. ‘The ministry wants guarantees that the ammonia targets will be achieved and therefore wants to reduce the nitrogen content of feed by law. There is a better method: the Kringloopwijzer tool lets farmers figure out themselves how they can cut the use of nitrogen. You appeal to their professional skills but you don’t have any firm guarantees beforehand.’
Migchels believes an average reduction in ammonia of 10 per cent is possible through this ‘feed route’. ‘There are farmers who use nitrogen efficiently but there are also lax farmers who feed the animals too much protein just to be sure. They could reduce ammonia by 20 per cent.’ The ministry’s third measure – encouraging cows in the field – will help to reduce ammonia emissions, says Migchels, but this too differs per farmer. He is curious to see how the Agriculture ministry incorporates the guidelines in legislation and regulations.