Plant, grain, and soil response of irrigated malt barley as affected by cultivar, phosphorus, and sulfur applications on an alkaline soil

Abstract

Information on the effects of phosphorus (P) and sulfur (S) applications on crop response and soil-P status of two-row malt barley (Hordeum vulgare L.) under high-input conditions are limited in alkaline soils despite widespread fertilizer-P and -S use. A field study was conducted during the 2015 and 2016 growing seasons where the barley cultivars (ABI-Voyager and Moravian 69) were grown at five rates of P (0, 37, 73, 110, and 147 kg P ha−1) and three rates of S (0, 112, 224 kg S ha−1). ABI-Voyager had significantly greater biological yield (17,023 kg ha−1) and grain yield (7433 kg ha−1) but a lower (44%) harvest index (HI) than Moravian 69 (15,037 kg ha−1, 7168 kg ha−1 and 49%, respectively). Grain yield increased with rate of P-application until 37 kg P ha−1 where the maximum calculated yield was obtained at 98 kg P ha−1 by a quadratic model. Sulfur application had no significant effect on any of the measured crop or soil parameters. Olsen P increased linearly with greater fertilizer-P applications, indicating grain-P removal was not sufficient to reduce or retain STP concentrations at initial levels when P was applied. Crop-P uptake and soil-P response to fertilizer P applications are important, as remaining soil P is available for subsequent crop usage and may have potential negative environmental impacts. Thus, cultivar selection and appropriate fertilizer-P and S management will ensure optimal agronomic and economic returns while minimizing potentially negative environmental impacts for two-row malt barley produced in the western United States.