A 2005 analysis found similar substitution among agricultural outputs in Spain (Custa etal., This economic behavior has implications for choices in which surface water versus groundwater infrastructure could each be improved or restored. For example, irrigators will invest $1000 today in a water conserving land improvement like drip irrigation if net farm income increases by more than $1000 over time, in present value terms. If not, irrigators will avoid making the investment. A range of resource allocation management decisions faced by farm managers can be addressed by applying one or more of these budgeting economic principles.