A RESPONSE ANALYSIS OF WHEAT AND BARLEY TO NITROGEN IN FINLAND

A nonlinear Mitscherlich function was found to be superior to quadrati c and square root functions in estimating yield response to nitrogen b ased on a Finnish sample of barley. Nonnested hypothesis testing (J-te st) indicated the Mitscherlich functional form to fit the data better than the quadratic form based on this sample. In the analysis of the c rop response for spring wheat the Mitscherlich functional form could n ot be proved superior by a J-test. The inferred profit maximizing nitr ogen fertilization levels based on the Mitscherlich functional form ex ceeded the quadratic polynomial forms and were lower than the inferred levels using square root specifications. Implementing 100% nitro-en p rice increases or 50% producer price reductions lowered the profit max imizing nitrogen application doses by 20-24%, according to the Mitsche rlich specification.