Diffuse losses of nutrients such as phosphorus (P) from agriculture and horticulture towards the environment are one of the main reasons for excessive P concentrations in surface waters in Flanders. If no significant improvement of these P concentrations occurs, the European Commission threatens to impose drastic measures on Flanders. These measures may jeopardise the profitability of the Flemish agriculture and horticulture sector. Nevertheless, the agricultural and horticultural sector has a major economic interest in Flanders. The entire sector has a final production value of about 5428 million euros, employs about 94500 people and creates a lot of upstream and downstream economic activity (Supply, processing...). As the necessary knowledge and instruments for a more efficient and sustainable P management in agriculture and horticulture were lacking, the project consortium led by Ghent University submitted the A-PROPEAU project application to the VLAIO. After approval, this project started in November 2014.

Thanks to the support of the VLAIO, this project led to the development of a thorough knowledge and a number of directly usable tools that allow using P more efficiently without compromising the agricultural and horticultural sector. A first development was a calculation tool that allows calculating the P-balance at field level. In this way, the farmer or horticulturist can avoid applying more P than he or she extracts form his field. Subsequently, a decision scheme was developed that allows the farmer and horticulturist to check whether the use of mineral P-fertilisation is useful. In addition, a calculation tool has also been developed that allows to determine which organic fertilisers can be replaced by sowing green manure. In this way, P mining can be pursued without negatively affecting the organic carbon content of the soil. P-filters were also developed. These make it possible to drastically reduce direct P losses from drains from agricultural and horticultural fields to the environment. All these and other developments within the project framework were cast into one decision support model. This model will be made publicly available via the agricultural and vegetable research centers Inagro, PCG and PSKW.