Nitrogen Fertilizer Requirement of Feed and Malting Barley Compared to Wheat, 2011

Barley is generally thought to require less nitrogen fertilizer than wheat, but how much less has not been clearly documented. The purpose of this study is to compare the nitrogen fertilizer requirements of barley and wheat. A study was conducted at the Maricopa Agricultural Center testing the response of 2 durum wheats (Kronos and Havasu), 2 bread wheats (Yecora Rojo and Joaquin), 2 feed barleys (Baretta and Nebula), and 2 malting barleys (Conrad and Moravian 69) to 7 rates of nitrogen fertilizer (0, 30, 60, 90, 120, 150, and 180 lbs N/acre). The surface soil was relatively high in nitrate at planting (19 ppm NO₃-N) contributing an estimated 76 lbs N/acre. Maximum yield was obtained at 156 (durum), 147 (wheat), 137 (feed barley), and 127 (malting barley) lbs N/acre. However, since the yield of durum and bread wheat was higher than feed and malting barley, the nitrogen fertilizer per 100 pounds of grain yield was similar for these crop types (~2.37 lbs N per 100 lbs of grain). If the 76 lbs N/a of nitrogen estimated to be available from the surface soil were included, then about 3.62 lbs of N would have been required per 100 lbs of grain for both wheat and barley. The N requirement reported in this study does not include the extra N potentially needed for wheat to obtain acceptable protein levels. In conclusion, wheat required more nitrogen fertilizer than barley to obtain maximum yield in our study, but the amount of nitrogen fertilizer required per 100 pounds of grain was similar