Wetenschap - 4 juni 2015

Phosphate ceiling for dairy farms

Albert Sikkema

Dutch dairy farmers are now required to improve the utilization of phosphorus by their herds. This is the only way they can avoid seeing state secretary Dijksma introducing a quota system for dairy cows in order to keep phosphate levels below the national ceiling, says LEI researcher Pieter Willem Blokland.

Dutch dairy farms produced manure last year containing 172.3 million kilos of phosphate. This is only just below the phosphate ceiling of 172.9 million kilos agreed with the EU. It is mainly dairy cows that are responsible for the higher phosphate production. But it is not just due to the expansion in dairy farming, says Blokland. ‘The phosphorus level in the grass was much higher than the year before. So the manure in 2014 contained more phosphate than in previous years.’

What to do?
‘The livestock sector needs to aim at a lower phosphorus intake. The easiest way of doing that is to put less phosphorus in the concentrate feeds. That can save a few million kilos of phosphate excretion. The dairy sector wants to bring in this measure in July already. Because of the cold spring I expect the phosphate levels in this year’s grass are lower anyway.

The secretary of state wants to introduce animal quotas; is that to the dairy farmers’ disadvantage?
‘Herds have grown from a total of 1.55 million in 2013 to 1.57 million in 2014. If old figures are used as a reference point, dairy farmers who have expanded get into trouble. They then have to buy animal quotas, just like the milk quotas. Most dairy farmers were happy to see the end of the milk quota. Now they could be replaced by an animal quota. Most dairy farmers don’t want that. So research must be started quickly on possible alternatives.