Availability of Well Water Nitrates for Cotton in Various Irrigation Systems

The Seymour Aquifer in the Texas Rollins Plains Region has the highest median nitrate-nitrogen concentrations (13.5 mg/L) among major aquifers in Texas. While this is an environmental concern due to drinking water standards, high nitrate-nitrogen in well water can save producers money if the nitrate is accounted for and credited toward nutrient management plans. A study is being conducted at the Chillicothe Research Station under furrow, pivot, and subsurface drip irrigation.  Various levels of N, as a result of accounting for well water N, have been applied over two cropping seasons.  Initial results show that fertilizer N applications can be significantly reduced without compromising production when well water nitrate is accounted toward nutrient management plans.