The paper explores and tests one of the contemporary principles of economic regionalization of agriculture by using differential land rents in wheat production as a model. The analysis is based upon the assumption that differential rents could serve as a valid principle for regional planning, particularly differential rent I. On the basis of the food self-sufficiency principle declared by the Rome Declaration on World Food Security, the model assesses the economic justification of the Croatian wheat incentives system in relation to wheat production potentials in the counties, starting from those with high potential (the most favourable agroecological conditions for wheat production) towards the counties with low potential, to the level of self-sufficiency as a long-term Croatian strategic vision. The model shows that Croatia can meet its requirements for industrial wheat processing at the level of cumulative farmland areas of three counties, while total consumption can be covered by production of eight counties. This model compromises the fundamental principle of regional economics of wheat production, because up to 2003 incentives were given for 78,000 ha more than what was economically justified for wheat production intended for industrial processing, i.e. for 19,000 ha for total wheat demand. But, wheat production is practised all over Croatia—in all agricultural regions because of tradition on the one side and crop rotation requirements on the other side. This conclusion points to an uneconomic allocation of budget funds for wheat incentives to the counties, whose output results do not justify the incentives. The current subsidy model stimulates production by applying the criterion of a minimum three-hectare area required for wheat incentives. Consequently, a part of wheat production is excluded from the incentive system in the counties with high potential farmland, i.e. in the counties collecting a differential land rent for wheat production, which is uneconomical in terms of macroeconomics. Even though the model featured in this paper exemplifies wheat production in this particular situation, it can be easily used to evaluate the efficiency of incentives for all the crops included in the incentive system, while applying the standards of economics and agricultural regionalization. It can also be used to determine subsequent, more economical distribution of production incentives by channelling uneconomically allocated budget funds into implementation of other agricultural policies and measures.