Carbon and nutrient cycling in organic agriculture: a chronosequence approach

Activity: Talk or presentationOral presentationOther


A key challenge is to increase sustainability in agriculture without yield loss. Organic agriculture uses no chemical
fertilizers and pesticides. Instead, yield depends on nutrients released from organic inputs, and thereby on
soil communities that drive soil carbon and nutrient cycling. However, these soil communities may need time
to establish, resulting in lower yields during the beginning of this conversion. How carbon and nutrient cycling
change during the conversion from conventional to organic agriculture is not well understood, but it may help
us to understand, and eventually reduce, the yield gap. Here, we studied how carbon and nitrogen cycling
change when converting conventional agricultural systems into organic agricultural systems. We used a chronosequence
approach, where we collected soil samples from 37 organic fields, on both sand and clay soils, that
have been converted from conventional to organic agriculture between 1 to 40 years ago and from neighboring
conventional fields. Under controlled conditions we measured potential rates of carbon and nitrogen mineralization.
Potential carbon mineralization and substrate induced respiration were higher in organic soils, but there
was no effect of time since conversion. This might be explained by variation in abiotic factors such as soil organic
matter content. We use our data to unravel how fast ecosystem processes change after the conversion of
conventional into organic farming systems. Our findings will yield important insights how the performance of
soil communities is changed during transition and this will help us to understand changes in crop yield.
Event title3rd Conference on Ecology of Soil Microorganisms
Event typeConference
LocationHelsinki, Finland
Degree of RecognitionInternational