Abstract:In the present paper the methodology of recommendation for the application rate of chemical fertilizer nitrogen(N) is discussed.Adaptation of the regional mean optimal application rate of chemical fertilizer N(RMOR) for the recommendation for rice and wheat crops is evaluated from the view point of yield efficiency,net income and environmental impacts based on the network of field experiments conducted in Tai Lake region in 1982—1985 and 2003—2004 years,respectively.It is suggested that the RMOR in combination with tuning according to the specific field conditions can be used for the recommendation.