From nutrient surplus ... 

This project will use manure from a large Polish pig farm where the foundation BalticSea2020 since 2011 has worked with and invested in facilities for manure separation, storage, and spreading. The amount of nitrogen and phosphorus excreted by the pigs at the farm is of similar magnitude as the amount excreted by the citizens of Uppsala, which is more manure than what can be efficiently used in the crop production at the farm. This situation results in a surplus of nutrients that increase the risk of nutrient losses to the environment.

This screw press is the first separation step, followed by a centrifuge.
This screw press is the first separation step, followed by a centrifuge.

... to a decrease in total nutrient budget

With the new manure handling facilities, the manure can be used more efficiently in crop production and the solid manure fraction can be exported to a nearby crop farmer, which decreases the nutrient surplus at the pig farm. This project will monitor and optimize the manure separation steps at the farm, so that a large proportion of the phosphorus ends up in the solid fraction of the manure. This is important because this farm, as well as many other large livestock farms, have large phosphorus surpluses. The solid manure fraction can then be used in crop production at other farms in the area, partially substituting for mineral fertilizers and contribute to decreasing the overall nutrient budget for the region.

Sampling and analysis

During the first months of 2018, Athanasios Pantelopoulos has taken many samples along the different steps of the separation process and his analysis of these samples will provide valuable information about how to optimize the system. He has also taken samples of the solid manure fraction that will be further processes and analyzed at SLU. The aim of this part of the project is to assess suitable post-treatments of the solid fraction of pig manure to upgrade it to a more stable, economically transportable and nutrient rich organic fertilizer. The processing and evaluation involves both lab treatment and analyses as well as pot experiments, which will be conducted during 2018.

Greenhouse experiments with pots can be used to assess the fertilizer value of various fertilizer products.
Greenhouse experiments with pots can be used to assess the fertilizer value of various fertilizer products.