AN EVALUATION OF ANION-EXCHANGE RESIN USED TO MEASURE NITRATE MOVEMENT THROUGH SOIL

The attribute that ion-exchange resins remove ions from solutions moving through them can be used to measure nitrate transport through soils. The characteristics of nitrate adsorption by resins must be known to interpret nitrate accumulation on ion-exchange resins embedded in soil. The extent to which anion exchange resins retain NO3- from soil leachate was measured in 15.9 cm diam.by 60 cm long intact cores of Nolin (fine silty mixed mesic Dystric Fluventic Eutrochroept) soil. A NO3--selective resin and a non-selective resin were tested. Columns were fertilized at a rate of 300 kg N/ha and 150 kg Br-/ha and leached with 50 cm of water. Under these conditions, both resins retained approximately 80% of the NO3- and Br- leached through the soil. This compared with greater than 95% retention in laboratory columns containing only resin. The difference in retention was attributed to different flow through the resin associated with the method of resin emplacement.