A decaying leaf on the forest floor has a C:N mass ratio of 50:1. A decomposer fungus with a biomass C:N ratio of 12:1 is breaking down the leaf and using it for growth with an efficiency of 40% (the fungus respires 6 g of C for every 10 g it decomposes and takes up). How much additional nitrogen does the fungus need to translocate from soil for each gram of biomass C growth