Innovation projects

Adaptation of a leek processing machine for waste water applications


In Flanders, there is much waste water from chemical air scrubbers (= ammonium sulphate) that are installed, as part of low-emission techniques, on pigsties and manure treatment/processing plants. This number can be expected to rise sharply in the context of the Flemish PAS initiatives (Programmatic Approach to Nitrogen Deposition). In Belgium, this waste water is recognized as an artificial fertilizer and can be used as nitrogen- and sulphur-rich fertilizer in agricultural crops. Because of decreasing sulphur deposition in the form of acid rain (due to improving air quality) the addition of sulphur in the fertilization process is appropriate for crops with high sulphur requirements. In leeks, this SO3 requirement amounts to around 60 kg per hectare. Waste water can contain between 4 and 8% N and 15 to 25% S depending on the type and controller of the scrubber. The sulphur content of the waste water is therefore also the limiting fertilizing factor because an excess of S prevents the absorption of other minerals. A fertilizer dose of 1,000 to 1,250 l per ha is therefore the norm. Dilution with urea reduces the S-content in increasing N-content.


In this project, a contractor's rotary cultivator and ridging machine will be adapted in order to dose waste water in leek crops (both full field and ridge cultivation) depending on the crops' growth stage and nitrogen requirements. Given that waste water is corrosive, the necessary machine parts will be made from corrosion-resistant materials. Mixing it with the soil offers the advantage of a minimal chance of leaf scorch and volatilization of the product.


Realisation of SME Verhoest Marc BVBA (Rumbeke)

At agricultural contractor Sander Verhelle (Pittem)

Together with Inagro and VCM

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