Closing the P Cycle: Increasing nutrient efficiency by improved P uptake by crops and recycling from residual flows (waste)

Phosphorus (P) is an essential element for all life on earth. The inefficient use of phosphorus (P), specifically in the food chain, is a threat to the global aquatic environment and it is depleting the earth rock-phosphate pool that is an essential finite natural resource being available in a limited number of countries. A higher resource use efficiency of P is thus essential to save rock-phosphate for future generations and to protect our environment.


The project is divided in two work packages:

-      WP1: Efficient P uptake and high quality crop production at reduced P fertilisation levels.

P application rates are legally decreased towards the level of balanced fertilisation or lower. This reduces the amount of readily plant available P in the soil, which may lead to P deficiency in crops. Therefore, an optimal use of soil P is necessary to avoid P deficiency and maintain crop production. Based on literature data and other sources an inventory is made of options to improve crop uptake of soil-P and/or fulfil P crop demand by small P applications. A number of promising options will be further detailed for testing in pot and/or field experiments.

-      WP2: Nutrient recycling from residual flow (waste).

Increasing nutrient use efficiency is important for phosphorus, as well as for other minerals that are essential for plant growth. Combining recycling of phosphorus with the recycling of other nutrients may increase resource use efficiency and enhance the circular economy. Efficient reuse of nutrients from residual flows can be realized by direct use (e.g. animal feed) or by a treatment based on chemical, physical and biological processes. This project makes an inventory of promising options to combine P recovery with recovery of other nutrients and organic matter from different residual flows, mainly within the waste sector. In addition, a framework for a tool will be developed to assess the agricultural applicability of fertilizer products from recycling. This tool aims to assist farmers in their fertilizer choice, and producers of recycling products to assess the applicability of their products for agricultural use. The project aims at recycling options for both developed and developing countries where drivers for reuse of nutrients may differ.

The project is part of the program Closing the P Cycle.