Animal manure use in vegetable production in the Netherlands

Application of animal manure in vegetables, when used right, can improve soil quality, crop production and financial returns on the long term. Use of animal manure closes nutrient and carbon cycles and contributes to several ecosystem services. The composition of animal manure varies considerably depending on animal species, housing system and feeding of animals. It is important to account for the composition of the manure when using it in vegetable production. Important aspects are the right selection of manure type, matching crop needs in nutrients and organic matter, and the right application of manure in time and place with minimum emissions. Animal manure is ample available in the Netherlands. It is widely used to cover nutrient needs and to sustain soil fertility in the intensive crop rotations in the Netherlands. Manure use in the Netherlands is severely restricted by legislation on nitrogen and phosphorus to prevent emissions to ground and surface water. Processing of animal manure is emerging to be able to use more manure in crop production efficiently next to other advantages for the animal farmer. Important processing techniques developed are 1) anaerobic digestion and 2) separation of manure in a liquid and a solid fraction combined with reversed osmosis making mineral concentrates. The value of animal manure for arable and vegetable crop production is difficult to calculate, especially for organic matter as it affects multiple processes in soil and plant growth. A first estimation of the value of animal manure for arable and vegetable farming on sandy soils is made based on a long-term experiment with different organic matter input treatments. Total value of slurry in the Netherlands is estimated between € 35 and 57 t-1 or € 430 and 2240 ha-1 based on input of 60 kg ha-1 of phosphate with slurry.