Center pivot irrigation capacity effects on maize yield and profitability in the Texas High Plains

In the Texas High Plains (THP), groundwater resources for irrigation are declining because of aquifer depletion and reduced well yield. Inability to meet peak water demands maize under constrained capacities decreases yield profitability. The MOPECO crop model, calibrated THP, was adapted simulate use center pivot evaluate allocation strategies limited irrigation. Simulations were carried out over a range (3 – 12 mm d-1 50.9 ha area), initial soil contents, application depths with allocated fraction (0.5 1.0) area. Fractional allocations achieved by withholding from circular sectors or outer spans unirrigated fractions in fallow planted dryland cotton. These evaluated growing seasons characterized typical meteorological years average (TMY1), above (TMY2), below (TMY3) precipitation. Preseason had little no influence on grain at ? 5 d-1. At ?6 TMY1, marginally greater yields ha-1 simulated when irrigated. For ?8 reducing irrigated area most prudent option optimize net returns. As increased 4 8 d-1, that maximized returns 0.5 0.9. Concentrating generated productivities lower seed fertilizer costs. Compared fallow, planting cotton portion except seasonal drought (TMY3). Because volume did not always increase returns, there is an opportunity both profitability conserve irrigating