A two-year field study was conducted to evaluate the effect of subsurface trickle irrigated cotton yields under varying fertility and irrigation levels in Trans-Pecos Region of Texas. Yield response curves were developed and used to determine the range of optimum inputs for the highest yield return. It was found that residual nitrogen in the soil dictated the amount of added fertilizer needed. For soils with low residuals, over 100 pounds per acre of added fertilizer was needed; for soils with higher residuals, a range between 50 to 90 pounds per acre was found to be satisfactory. For either residual level, an irrigation range from 1.0 to 1.5 inches per week provided the best results with respect to lint yields. The study also provided insight on the benefits of subsurface trickle irrigation despite its high initial cost.