Evaluating Alternative Water Allocation Strategies for Maximizing Returns to Irrigation for Wheat in the Texas Panhandle under Declining Water Availability

Depletion of the Ogalalla Aquifer and increasing energy costs reduce profit margins makeing management strategies more critical. Management strategies evaluated include: 1) utilizing measurement of available water to determine the optimal irrigation to maximize the returns to irrigation, and 2) using the Percent Potential Evapotranspiration (PPET) to determine the optimal irrigation to maximize returns. The strategies are evaluated under average, first quartile, and fourth quartile levels of September through June precipitation as measured at the Amarillo International Airport. Both indicate that under average precipitation returns to irrigation are only positive for combinations of high crop prices and low energy costs. With above average precipitation costs increase more rapidly than revenues resulting in a reduction in net profit. When precipitation is in the fourth quartile returns to irrigation are greatly increased. The criterion based on available water indicates higher irrigation levels and higher returns to irrigation than the method utilizing PPET.