Nitrogen use efficiency by winter barley under different climatic conditions

Abstract The proportion of straw and grain as well as of nitrogen (N) in the barley (Hordeum vulgare L.) plant was greatly changed by the distribution of rain in the pre‐ and post‐anthesis periods and by the existence of air temperatures above 30°C during grain filling along with N fertilizer rate. The response of barley to N rates of 0, 40, 80, 120, and 160 kg N/ha was studied over a three‐year period. Adequate rainfall in the pre‐anthesis period, little rain in the post‐anthesis period, and air temperatures above 30°C during the hard dough stage of the grain development, produced high N translocation to the grain as well as a positive response on grain yield and N content in the grain up to a fertilizer rate of 118 N kg/ha. Above this rate, grain yield decreased, while the N content in grain continued to increase. Optimum moisture conditions during the pre‐ and post‐anthesis periods, and mild temperatures during the grain filling period, produced a good grain yield response to N fertilizer rate, increas...