Comparison of Nitrogen Fertilizer Methods for Irrigated Barley in the Northern Great Plains1

Abstract

AbstractYield response curves that consider differences in the effectiveness of fertilization practices are necessary to increase the accuracy of yield response predictions. Such curves are lacking for the northern regions of the Great Plains. A comparison of three commonly used N fertilization practices (broadcasting urea, broadcasting ammonium nitrate, and banding anhydrous ammonia) was conducted to determine their relative efficacies for irrigated barley (Hordeum vulgare L. ‘Gait’) production and to develop N response curves. Spring and late‐fall applications were also compared. Field plots were established on Aridic Haploboroll (Brown Chernozemic) and Typic Cryoboroll (Dark Brown Chernozemic) soils in southern Alberta between 1981 and 1984. Fertilizers were added in late fall or early spring at rates of 30,60,90, and 120 kg N ha−1. Broadcast fertilizers were incorporated into the top 20 mm of surface soil. Anhydrous ammonia resulted in significantly greater barley grain yield responses to N than the addition of urea. Yield responses to ammonium nitrate were intermediate between those for anhydrous ammonia and urea. The fertilizers did not differentially affect grain and straw N concentrations. Application of N fertilizers in the fall, after soil temperatures fell below 5°C, did not result in yields lower than those obtained by equivalent spring‐applied treatments. Yield response equations were developed for the combinations of fertilizer and time of addition.