Emission und Aufnahme von Lachgas und Methan durch Ackerböden in der Fruchtfolgesequenz Kunstwiese – Silomais unter konventioneller und biologischer Bewirtschaftung

Summary

Organic farming systems provide multiple environmental benefits. Concerning climate change they have a substantial mitigation potential. Skinner et al. (2014) evaluated with Meta-Analysis the global dataset on comparative field measurements of soil greenhouse gas (GHG) fluxes under organic and non-organic agricultural management that have been published by the end of 2012. They showed that for arable land-use under organic management compared to non-organic 1) the cumulated area-scaled N2O emissions are about 15 % lower, 2) yield-scaled N2O emissions are slightly higher and 3) CH4 uptake is higher. However, this database is thin and further field measurements covering whole crop rotations are needed to close knowledge gaps. Therefore soil GHG fluxes are measured since August 2012 in the DOK long-term experiment. Thereby the findings of the Meta-Analysis serve as hypotheses. The measurement results from a grass-clover - maize crop sequence confirm the hypotheses one and three. However hypothesis two was significantly rejected by the biodynamic system compared to the conventional system with farmyard manure.