Optimizing stocking rate for maximum return to a wheat–cattle enterprise using model simulation and economics
Managing dual-purpose wheat is complex because of the tradeoff relationship between cattle (Bos taurus) and wheat (Triticum aestivum L.) production. Stocking rate (SR) and planting date are key decision variables of the dual systems. The objective was to develop decision support information that help farmers boost profits by adapting SR and planting date to particular production and market conditions. A wheat grazing model was used to simulate the systems for seven SR (0–3 head ha–1), five planting dates, three climate scenarios, and two initial soil moisture profiles. Net returns were estimated for three representative markets. Net returns under optimized management doubled those under the business-as-usual for the comparable planting dates, indicating great potentials to boost net returns with better management. Optimal SR depends on markets and forage availability. For market that overwhelmingly favors grain production, grain-only wheat should be used; whereas dual-purpose wheat is preferred under other market conditions. For wet soil at planting, maximum returns are attained in early September planting at high SR of > 2 head ha–1 despite climates; however, the high optimal SR should be adjusted down with delayed planting in wet and average but maintained in dry climate for water conservation. For dry profile at planting, optimal management is dual-purpose wheat with SR of 3 in wet, grain-only wheat in average, and fallow in dry climate. Had wheat been established in severely dry years, moderate grazing at 0.5 to 1.5 SR could reduce net losses. Under most circumstances, grazing should not be allowed to pass first hollow stem to maximize returns.