Carlsson et al., 2003. Plant and Soil, 253 (2): 353-372 Document reference Carlsson, G.; Huss-Danell, K., 2003. Nitrogen fixation in perennial forage legumes in the field. Plant and Soil, 253 (2): 353-372 Web http://dx.doi.org/10.1023/A:1024847017371Citation key Carlsson et al., 2003Datasheets Red clover (Trifolium pratense)