Table 1: Means and Standard Deviations of Carbon and Nitrogen contents (d.w.%) and C/N ratio in Azolla strains from Dec. 2000 to May 2001. We observed high quantities of Nitrogen in the leaves of the Japan and Italy strains; it was probably related to the decrease of its biomass during our test. The Milan strain showed lower Nitrogen content, but a good C/N ratio associated with a high RGR (see Figure 1).

Strains %C %N C/N Milan mean 38.854 2.581 15.582 std 1.66 0.48 2.58 Sweden mean 37.722 2.097 18.166 std 2.04 0.18 1.73 Germany mean 38.244 2.248 17.165 std 1.87 0.18 1.60 Italy mean 40.374 2.631 15.606 std 0.98 0.33 2.08 Japan mean 41.294 3.025 14.336 std 1.26 0.59 3.66