Yield and Economic Responses to Phosphorus Fertilizer Placement in Dual‐Use and Grain‐Only Wheat Production Systems
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Wheat (Triticum aestivum L.) production in the southern Great Plains is a unique enterprise that provides both high-quality forage and a grain crop within the same growing season. However, information on fertility management programs to maximize forage and beef production in a dual-use wheat production system is lacking. A 3-yr, field-scale production study was initiated on a Tillman clay loam near Vernon, TX, in 1999 to (i) determine the influence of P fertilizer and P fertilizer placement on forage, beef, and grain production from dual-use wheat, and (ii) compare economic costs and returns of dual-use and grain-only wheat production systems. Varying numbers of stocker cattle (Bos spp.) were placed in each pasture based on forage availability. Beef-to-forage allowance among pastures was kept relatively constant by adjusting cattle numbers monthly. Applying 20 kg P ha-1 yr-1 increased soil test P in the upper 15 cm two- to threefold, forage production 18 to 54%, and animal gains ha-1 27 to 29% compared with no P. With respect to forage and subsequent beef production, surface-applied P was generally equal to or better than injected P. Average return between the graze-plus-grain and graze-out systems was significant (P < 0.0001) but not among fertilizer treatments (P = 0.26), although surface-applied P resulted in numerically higher returns each year. There was no significant system X fertilizer treatment interaction. However, during the study period, the graze-plus-grain system was clearly superior to the graze-out system in generating higher net returns ($94 vs. $29 ha-1). © American Society of Agronomy.
author list (cited authors)
Sij, J. W., Pinchak, W. E., Malinowski, D. P., Robinson, D. L., Bevers, S. J., Baughman, T. A., & Gill, R. J.