Crop production encompasses corn, soybeans, wheat, alfalfa, and sweet clover, each of which is produced by different methods and in different rotations. Purchasing and marketing activities include buying inputs and selling farm outputs, with all grain being sold at harvest. Financial management includes credit, debt, and investment or loan management. These financial activities run on an annual basis for the entire five-year planning period. The resource constraints are land, labor, and capital.
Land is considered homogeneous.
The number of acres remains constant because no land is purchased or sold. The constraint on labor is the amount of labor available in each month of the year. The solutions for the model give the nitrogen balance, farm income, and optimal cropping systems for each of the commercial nitrogen fertilizer allotments. These allotments, established by a regulatory agency, are the amounts that the farmer may purchase each year. Various cropping systems are possible in this model.