Kann man bei der Nährstoffbilanzierung im ökologischen Anbau mit den üblichen Faustzahlen rechnen?

Summary

Nutrient budgets are an important tool of farm planning. Normally the amounts of manure, feedstuffs, yields etc. as well as their nutrient contents are measured and analysed in each single case. If this is impossible for labour reasons, standard data sets of nutrient contents in agricultural products have to be used. However, these data sets have been determined in conventional farming. Thus, the question arises, whether theses results can be transferred to organically grown crops. This question was investigated with rye samples of a long-term trial with farmyard manure and mineral fertilization.
In many cases the N, P and K contents in organically and minerally fertilized samples differed significantly, though one of the treatments did not always show the higher or lower results. Manure fertilized rye had lower N contents in seeds and straw; the straw had more P but less K and higher ash contents than in the mineral treatment. It has to be concluded that miss-calculations in nutrient budgets are to be expected, if conventional values are used for organic products.