LYSIMETER MEASUREMENTS OF NITRATE AND CHLORIDE LOSSES FROM SOIL UNDER CONVENTIONAL AND NO-TILLAGE CORN

Salt and water movement was studied using steel pan lysimeters in the field under corn (Zea mays L. ) grown in killed sod and with conventional tillage. The study was done to determine the actual leaching losses of nitrogen under the two tillage systems. Losses of nitrate nitrogen and chloride used as a tracer of nitrate ion were higher under the no-tillage system as measured in the leachate collected after rainfall. This loss could occur within 1 to 2 months after the application of the nitrogen. Concentrations of nitrate and chloride ions in the leachate indicated that these mobile, surface-applied anions could be washed into natural soil cracks and channels and flow much deeper into the soil than predicted by miscible displacement theory.