YIELD RESPONSE OF CONQUEST BARLEY AS AFFECTED BY NITROGEN FERTILIZER AND SOIL TESTS FOR AMMONIUM- AND NITRATE-NITROGEN

Abstract

Yield response of Conquest barley to nitrogen fertilizer applied at 22, 45, 67, and 134 kg/ha with and without 20 kg P/ha were significantly related by regression analyses to ammonium- and to nitrate-nitrogen in soils of northeastern Saskatchewan. Both linear and quadratic equations obtained from the regression analyses were used to develop tables estimating yield response of barley related to nitrogen fertilizer rates and soil tests for ammonium- and nitrate-nitrogen. The results indicated that a greater response to nitrogen fertilizer occurred with a given amount of ammonium- plus nitrate-nitrogen than with the same amount of nitrate-nitrogen alone. Phosphate fertilizer also significantly increased yield response to nitrogen fertilizers. Confidence intervals showed that wide variation could be expected in yield response to nitrogen fertilizers. Variation is attributed to differences in soil type, soil moisture, and climatic factors among experimental sites.