Opportunities and Constraints in the Recycling of Nutrients

Keywords: Nutrients, Recycling, Livestock waste, Food industry waste, Household compost, Toilet waste.

In Europe, the nutrients available from various sources have to be used efficiently, and carefully recycled. In some parts of the developing world, mineral fertilisers are required to increase the amount of nutrients available for recycling.

For many livestock farmers in Europe, legislation will limit the maximum amount of nutrients which can be applied annually, and the challenge will be to increase the efficiency of nutrients applied with manure.

Waste management in Sweden is currently changing and both source separation of organic household wastes and urine separation using different toilet models constitute two promising developments.

Although the amount of P that can be recycled through sewage sludge is large or larger than the amount of P present in human urine, it is doubtful whether sewage sludge can be applied to arable land due to a rapid heavy metal contamination of soils. Urine separating toilets enable an improved recirculation of N and K compared to the present system.

Emissions of NH₃ constitute the largest N loss pathway from all biological wastes of society. Thus, methods and practices to reduce NH₃ losses are of great importance for successful recirculation of nitrogen in organic wastes.

A successively increasing recirculation of plant nutrients present in township wastes through recirculation of compost from organic household wastes and human urine will significantly reduce the need for inorganic N fertilisers.

PART 1:

OPPORTUNITIES AND CONSTRAINTS IN THE RECYCLING OF NUTRIENTS.

Joachim Lammel, Hydro Agri Europe, Hanninghof

2 figures, 7 tables,13 refs.

PART 2:

OPPORTUNITIES AND CONSTRAINTS IN THE RECYCLING OF PLANT NUTRIENTS – CASE STUDY SWEDEN.

Prof. Holger Kirchmann, Swedish University of Agricultural Sciences, Uppsala

2 figures, 6 tables, 25 refs.

36 pages