Public summary

Testing NEO fertiliser as an alternative to mineral fertiliser

N2 Agri/N2 Applied

July 1, 2026

Alternative fertilisers need to be tested in the potato field first

Nitrogen top dressing remains important in potato cultivation, but dependence on mineral fertiliser and emissions create a need for alternatives. In open field cultivation, an exploratory trial tested whether enriched organic fertiliser could perform comparably to mineral fertiliser nitrogen in potato top dressing. This public summary focuses on NEO. NEO stands for Nitrogen Enriched Organic fertiliser, an organic fertiliser enriched with nitrogen. In this case, pig manure is enriched with nitrogen using plasma technology. The trial looked at two things: whether plasma technology measurably changes the manure, and whether NEO fertiliser performed comparably to mineral fertiliser in potatoes in this trial.

Innovation package, use case and test type

    Status: afgerond

    Technical functionality

    Broad knowledge question

    Can NEO fertiliser perform comparably to mineral fertiliser in potato top dressing?

    The study examined whether plasma technology can help produce NEO fertilisers for more sustainable and effective nitrogen top dressing. It also examined whether this fertilisation route could help reduce dependence on mineral fertiliser and lower emissions.

    This study specifically looked at top dressing in ware potatoes. The question was what role NEO fertilisers could play in that context and whether their performance in the trial was comparable to that of mineral fertiliser.

    Approach

    From enriched manure to comparison in field trials

    At the VD Borne campus in Reusel, pig manure was treated with plasma technology. Samples were taken before and after treatment to determine whether the manure had been enriched with nitrogen.

    The NEO fertiliser was then compared with mineral fertiliser for top dressing in potato field trials. This was done at the WUR trial farm in Vredepeel and at the VD Borne campus in Reusel. In Vredepeel, the trial was carried out as a field trial with four replicates. In Reusel, it was carried out as a strip trial without replication.

    Goal

    Show what plasma technology does to manure and top dressing

    The study set out to answer two questions.

    • The first was whether treating pig manure with plasma technology enriches the manure with nitrate nitrogen.

    • The second was whether top dressing with NEO fertiliser was comparable to top dressing with mineral fertiliser. In this way, the trial focused on the practical value of NEO as an alternative to mineral fertiliser nitrogen in potatoes.

    Result and reflection

    More nitrate in the manure, no measured difference in yield

    The measurements showed that plasma technology led to a clear increase in nitrogen content through additional nitrate. The pH of the manure also decreased clearly.

     

    In these field trials, tuber yield and nitrogen uptake did not differ between NEO fertiliser and mineral fertiliser. This result needs careful interpretation, because the potatoes at both locations showed only a weak response to nitrogen. This made it difficult to demonstrate possible differences between the fertilisers

     

    Successful outcomes

    • The trial showed that plasma technology enriched the pig manure with additional nitrate.

    • The pH of the manure decreased clearly after treatment with plasma technology.

    • The field trials found no difference in tuber yield or nitrogen uptake between NEO fertiliser and mineral fertiliser.

     

    Lessons learned

    • The weak response to nitrogen at both locations makes it difficult to demonstrate differences between fertilisers.

    • Field trials remain important for properly assessing the practical value of alternative fertilisation.

    • Future assessment should take the weak nitrogen response in this trial into account.

    Leading Partners involved