Also in this case the period that must be considered is of more that one year. Cost benefit analysis technique has been used. In particular a life cycle of 10 years has been considered for poplar, whereas for walnut tree 40 years have been considered. 2080 grants for initial inv. Note that, cause to the fact that all the costs are referred to the unitary surface it is not correct to say that sensitivity analysis can be conducted on surface.
Farmers know from centuries that more the crop is fertilised more it produces.
They also know that if too much fertilised is used the crop can decrease its production. The neo-classical economist looked at the function of such a type in order to apply marginal analysis. This because this is the fertiliser that better fit the above deduction. In realty, the crop also uses the antecedent availability of Nitrogen into the soil. So, the quantity of Dc consumed by the crop is lower for the reason that part of the yield is obtained using the soil reserve of Nitrogen.