Nutrients in wastes and fertilisers

Optimisation of nutrient utilisation is important for reducing emission of nutrients to the environment and for achieving a high level of resource use efficiency. Animal manure is a very important nutrient resource in Denmark and knowledge about animal manure nutrient cycling and availability in the short and long term is important for achieving good nutrient utilisation.   

In connection with an increased use of bioenergy it is also important to ensure a high degree of sustainable recycling of nutrients back to agriculture. Organic farming can tackle its challenges with regard to ensuring a high nutrient supply level by, for example, improved use of green manure and animal manure and by increased recycling of nutrients from cities. 

We have a focus on the following topics: 

  • Cycling of carbon and nitrogen from animal manure and utilisation and loss of nitrogen in the short and long term
  • Importance of manure treatment (bio-degassing, separation) and addition of additives to the manure (e.g. acid, nitrification inhibitors) for nutrient utilisation and loss
  • Emission of greenhouse gases with various types of handling and treatment of organic fertiliser
  • Improved utilisation of phosphorous in animal manure
  • Assessment of plant availability of phosphorous and potassium in waste products and residues such as ashes, biochar, wastewater sludge and meat and bone meal.
  • Side effects of adding fertiliser, e.g. on uptake of heavy metals in crops