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Barley yield response to irrigation and potential profits in the Texas High Plains

Research paper by W. L. Harman, C. Regier, V. D. Lansford, F. Petr, T. H. Marek

Indexed on: 01 Jul '90Published on: 01 Jul '90Published in: Irrigation Science



Abstract

Irrigated winter barley (Hordeum vulgare L.) can be a profitable alternative to some low profit major crops in the Texas High Plains. A six-year evaluation of yield response related to total spring irrigation water, applied by surface methods (furrow), and seasonal precipitation resulted in a multivariate function explaining 74% of the yield variation. Predicted yields varied from a low of 3.69 Mg ha−1 to a maximum 6.18 Mg ha−1 with 0 and 389 mm, respectively, based on average monthly precipitation quantities. Precipitation is skewed to less than average in th semi-arid Texas High Plains. Using modal precipitation amounts of 40% of average precipitation, yield estimates were reduced to 2.29 Mg ha−1 with zero spring irrigation and to 5.63 Mg ha−1 at the peak with 450 mm. A second multivariate yield response function related to alternative timings of single and multiple spring irrigations explained 76% of the variation in yields. Among all combinations of 1, 2, 3, and 4 spring irrigations, irrigation water-use efficiency was estimated to be highest with one application at the boot stage of development. All other single and combinations of multiple irrigations resulted in lower water-use efficiencies. A comparison of enterprise budgets of four irrigation timing alternatives and levels of application indicated highest profit over variable costs, $ 287 ha−1, was attained by applying a total of 307 mm in three spring applications at the boot, head, and milk stages. A lower level of 217 mm applied at boot and milk stages was $ 12 ha−1 less profitable and a higher level of 425 mm was $ 24 ha−1 less profitable. When fixed costs of irrigation facilities, land, and machinery were considered, returns to management and risk were highest, $ 101 ha−1, with 217 mm. Using 40% of average precipitation, profits were reduced $ 65 ha−1 with 217 mm and $ 69 ha−1 with 307 mm spring irrigation levels.