Improved nutrient management for 250 dairy farmers

Livestock generate organic waste compounds such as phosphorus and nitrogen that leak into the environment, polluting ground and surface waters (as well as soil and air). This was the case in the Dutch province of Gelderland, which raised concerns about the quality of drinking water in the province. 

Vruchtbare Kringloop Achterhoek (VKA) is a collaborative initiative of farmers, water suppliers, the water board Waterschap Rijn en IJssel, the province of Gelderland and multinational companies in the Netherlands. To tackle the problem, VKA tailored livestock diets to provide the exact quantity of nutrients they need and increased the yields of feed crops as a means to absorb more nutrients in the soil and hence reduce the overall surplus of minerals. 

The project resulted in the elimination of phosphorus surpluses on the farms, as well as a 9% reduction of the nitrogen surplus in the soil. Overall, 25% of the companies involved were able to use 100% of their phosphorus and 48% of their nitrogen—meaning more farmers provided an optimal amount of nutrients to their feed crops without significantly exceeding a level that pollutes the soil. Subsequently, farmers registered an overall increase in milk production and lowered costs for the disposal of manure, as most of the manure produced was used on-farm.