Sulfuric Acid for the Treatment of Ammoniated Irrigation Water: I. Reducing Ammonia Volatilization

Abstract Effects of sulfuric acid applied to ammoniated irrigation waters on ammonia volatile losses are analyzed theoretically and evaluated by laboratory and field experiments. Volatile loss of ammonia from irrigation waters is directly related to the concentration of NH 4 OH. Sulfuric acid application reduces the concentration of NH 4 OH relative to the total N applied as anhydrous or aqua ammonia, principally by lowering pH. This consequently reduces ammonia volatile loss, e.g., by as much as 50% when acid is applied at rates equivalent to ammonia. The reduction of ammonia loss by sulfuric acid application through forming NH 4 SO 4 ‐ is nil. Simultaneous application of acid and ammonia may serve as a practical means of controlling ammonia loss as well as disposing of large quantities of projected surplus acid without reducing pH of irrigation water.