DISPOSAL OF SODIUM IONS IN SOIL

LIMESTONE AND GYPSUM WERE SURFACE APPLIED TO THREE SITES ALONG MAINE HIGHWAYS WHERE SODIUM LEVELS HAD BEEN RAISED APPRECIABLY BY ROAD SALTING FOR DEICING PURPOSES DURING PREVIOUS WINTERS. BOTH MATERIALS WERE APPLIED AT RATES EQUIVALENT TO 2, 4, 8, AND 16 MILLI-EQUIVALENTS OF CALCIUM PER 100 GRAMS OF SOIL. SOIL SAMPLES FROM THE PLOTS WERE ANALYZED 6, 12, AND 18 MONTHS FOLLOWING TREATMENT TO DETERMINE THE EFFECTIVENESS OF CALCIUM IONS IN REPLACING SODIUM IONS HELD BY THE SOIL PARTICLES. CALCIUM LEVELS IN THE SOIL AT ALL SITES WERE SIGNIFICANTLY INCREASED BY LIMESTONE APPLICATION, BUT THE SODIUM LEVELS REMAINED UNCHANGED. MAGNESIUM LEVELS TENDED TO DECREASE WITH INCREASED RATE OF LIMING, WHILE POTASSIUM AND PH VALUES REMAINED RELATIVELY CONSTANT. GYPSUM TREATMENTS SIGNIFICANTLY INCREASED THE CALCIUM LEVELS IN THE SOILS, ALTHOUGH LESS THAN LIMESTONE. AT THE 6-INCH DEPTH, SODIUM LEVELS WERE SIGNIFICANTLY REDUCED BY THE TREATMENT, WHICH GAVE 16 MILLI-EQUIVALENTS OF CALCIUM (14 TONS GYPSUM/ACRE) AT SITES WHERE THE ORIGINAL SODIUM CONCENTRATION WAS 734 AND 397 PPM. MAGNESIUM, POTASSIUM, AND PH VALUES WERE GENERALLY UNCHANGED BY GYPSUM TREATMENT. GYPSUM APPLIED AT A RATE EQUIVALENT TO 14 TONS PER ACRE TO THE SITE WHICH ORIGINALLY CONTAINED 734 PPM OF SODIUM RESULTED IN A 31% REDUCTION 18 MONTHS AFTER TREATMENTS WERE APPLIED. /AUTHOR/

  • Supplemental Notes:
    • Tp 71-10c, 23 PP, 1 FIG, 14 TAB
  • Corporate Authors:

    Maine State Highway Commission

    Materials and Research Division, Bureau of Highways
    Augusta, ME  USA  04330
  • Authors:
    • Hutchinson, F E
  • Publication Date: 1971-9

Subject/Index Terms

Filing Info

  • Accession Number: 00238032
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 10 1972 12:00AM