%T Examining root nodule activity on legumes %I Research Institut of Organic Agriculture (FiBL) and Norwegian Centre for Organic Agriculture (NORSØK) %K plant symbiosis, nitrogen fixation, Protein crops, soil functions, FertilCrop, FiBL1008401 %C Frick and Tingvoll %D 2017 %S FertilCrop Technical Note %X The symbiotic partnership between bacteria and legumes is vital for the supply of biologically fixed nitrogen to soil and plants in organic cropping systems. Perennial clovers in a dense grass clover ley may contribute more than 200 kg nitrogen (N) per ha and year to the cropping system from the second year after sowing. This technical note aims at encouraging farmers to take a closer look at the roots of legumes and become more familiar with the process of nitrogen fixation and its relevance for organic farming. The note provides some key information on biological nitrogen fixation and describes a simple method for examining nitrogen‐fixing root nodules. %A Reidun Pommeresche %A Sissel Hansen %L orgprints31344