Suitability of cotton as an alternative crop in the ogallala aquifer region
Renewed interest in cotton (Gossypium hirsutum L.) production in the Ogallala Aquifer Region can be linked to development of early maturing varieties, rising energy costs, and declining water levels in the Ogallala Aquifer. The main objectives of this study were to assess the feasibility of growing cotton and estimate the cotton yield potential and the potential reduction in Ogallala Aquifer withdrawals by producing cotton as an alternative to corn. For this purpose, the heat unit based, county-wide exceedance probability (P) curves for potential cotton yield were developed using a long-term air temperature dataset (1971–2000), and counties that have the potential to produce cotton every year (P = 0.99), 4 out of 5 yr (P = 0.85), and 3 out of 4 yr (P = 0.75) return periods were identified and mapped. Results indicate that 91 of 131 counties in the study area have the potential to produce cotton with lint yield > 500 kg ha–1 3 out of 4 yr. A county-wide lint yield goal based on a 3 out of 4 yr scenario may improve the chances for better profits to producers than with lint yield that can be expected every year. However, management uncertainties on water use efficiency; fuel, fertilizer, and pest management costs; and planting and harvesting schedule may require further consideration for estimating potential profitability. Nevertheless, these results show that cotton is a suitable alternative crop for most counties in southwest Kansas and all counties in the Texas and Oklahoma Panhandles. In addition, a significant reduction in water withdrawals from the Ogallala Aquifer for irrigation is probable if producers were to convert 50% of their land under corn to cotton production.