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Calculation of Optimal Nitrogen Fertilizer Rates
Author(s) -
Bullock David S.,
Bullock Donald G.
Publication year - 1994
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1994.00021962008600050030x
Subject(s) - cropping , fertilizer , profit (economics) , yield (engineering) , agriculture , nitrogen , nitrogen fertilizer , mathematics , agronomy , economics , agricultural engineering , agricultural economics , environmental science , ecology , biology , microeconomics , chemistry , engineering , materials science , organic chemistry , metallurgy
Agronomists sometimes fail to apply sound economic theory when recommending economically optimal nitrogen fertilizer application rates. Producers' objectives, producers' attitudes toward risk, and the effect of N on second and higher moments of the yield distribution are often left unstated or ignored. If a farmer knew, prior to N application, the future values of all stochastic factors that affect yield response to N during the growing season, optimal N rates could be established for each individual site‐year. However, farmers do not have perfect knowledge, so recommended rates should not change from year to year for a given site. We propose a more economically sound method for deriving economically optimal N fertilizer application rate recommendations. Our method maximizes profit on average over observed years for a given site. Long‐term field experiments from Illinois demonstrate that our proposed method increases profit from a trivial $0.18 ha −1 yr −1 to a substantial $103.41 ha −1 yr −1 , depending on site and cropping sequence. We call for increased collaboration among agronomists and agricultural economists in the economic analysis of fertilizer application.