Optimal length of the grass-clover period in crop rotations: results of a 9-year field experiment under organic conditions

Summary in the original language of the document

A nine year crop rotation experiment was carried out in the Netherlands from 2002 through 2010 to (1) determine the optimal length of the grass-clover (mixture) and maize period in crop rotations and (2) to determine which crops should receive slurry application with priority in case the availability of cattle slurry is limited.
The results show that dry matter yield decreased for all treatments over the experimental period, due to a decrease in plant-available N (from N fixation by the clover, applied slurry and mineralization of soil N). The relative yield increase (increase relative to the negative trend) due to slurry application was largest when all crops received slurry application, and the effects of slurry application increased over time.