If fertiliser prices go up the optimum close should

If fertilizer prices go up the optimum close should come down.
A fertilizer is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients.
The price of fertilizer has gone up and large-scale farms have begun to use less fertilizer. If large-scale farms keep reducing their use of fertilizer subsidies, they have no choice but to optimize the fertilizer they have which would therefore gain an increase in both grain yield and profit.