A farmer wishes to apply fertilizer to each of several plots. The additional crop yield from plot i per unit of type k fertilizer applied is aik, and the runoff into streams is cik.
There are storage facilities on the farm for at most k different kinds of fertilizer.
Formulate the problem of identifying which fertilizer to apply to each plot, and how much, to maximize total additional yield subject to an upper limit U on the amount of runoff.
Now, reformulate the problem using an indexed linear constraint. Hint: the nvalues constraint is useful here.