The desk study is based on agricultural statistics as well as on expert knowledge from the participating institutions. The nutrient demand is quantified based on the area of crops grown per region, the yield levels, the fertiliser recommendations, the soiltypes (clay, silt, loam, sand), the soil quality (bioavailability of the nutrients in the soil), the current legislation and common fertiliser practice. Besides the demand, the regional availability of nutrients in animal manure and other organic fertilisers is also quantified. From the regional demand fornutrients on the one hand and the regional availability of manure nutrients on the other hand, the net potential demand for nutrients in RDFs is quantified and desired N-P-K ratios are calculated.Results show that demand for nutrients from recycling exists everywhere, even in regions with high livestock density where animal manure is already largely used as a source for nutrients. However, the desired composition in terms of the three main plant nutrients, N, P and K as well as organic carbon differs largely between regions.
Overall, it can be stated that a pure concentrated recycling-derivednitrogen fertiliser will find its use everywhere. It is common practice to apply a basis fertilisationin terms ofN, P and K, often in the form of animal manure,butmost crops receive an additional nitrogen supplement during the growing season. Such aconcentrated nitrogen fertiliser will be demanded in grassland and cereal regions with high animal manure availability such as in the Netherlands or Flanders(Belgium).In Ireland on poor soils, an N-P-K fertiliser will be demanded. Root crop and vegetable regions with high availability of animal manure (the Netherlands and Flanders) are likely to demand anNK fertiliser whereas root crop as well as cereal regions with low availability of manure (Northeast France and Southwest Germany) are likely to demand an N-P-K fertiliser.
A demand for organic matter amendments additionally to regionally available manure can only be expected in regions with low availability of animal manure (e.g. locally in Germany and in France), especially if crops are grown which leave behind low amounts of organic matter with crop residues.In root crop and vegetable regions with animal manure input (the Netherlands and Flanders) a demand for a soil improver (high organic carbon content, low P content) can be expected.Besides the aspect of nutrient composition as assessed with this report, a lot of other aspects such as ease of use, nutrient value, safety and knowledge and awareness of farmers towards this topic determine whether RDFs will be purchased and applied to fields by farmers in the future or not.
