Ökologische Bewirtschaftung erfordert die Steuerung von innerbetrieblichen Nährstoffflüssen

Summary

Self-organised ecosystems are characterised by a high efficiency in the use of limited nutrient resources whereas the productivity is generally low. To utilise the potentials of agro-ecosystems with respect to a high nutrient efficiency, there is a need to steer the nutrient flow and provide good starting and adaptation conditions for living organisms.
While organic standards provide no operational guidelines on how to improve nutrient management, a concept was developed to improve N-efficiency on the farm level. N-import into the farm and N-flow through subordinate sub-systems (‘livestock’, ‘dung storage/ distribution’, ‘arable land/pasture’, and ‘feed storage/distribution’) were assessed on 9 organic and 7 conventional dairy farms, based on farm specific data and by making use of equations from the literature to estimate relevant figures.
N-efficiency varied considerably between sub-systems within and between farms, however showing no significant difference between the production methods. The results indicate a large but farm specific potential for improvements, contradicting any attempts of generalised statements and recommendations. Instead of minimum standards, a high level of N-efficiency that is beyond the average of conventional farms should be established as a leading aim in organic agriculture to justify claims.