EFFECT OF CLAY TYPE AND EXCHANGEABLE CATIONS ON AGGREGATION AND PERMEABILITY OF SOLONETS SOILS

SOLODIZED SOLONETZ SOILS ARE CHARACTERIZED BY AN UNDESIRABLE STRUCTURE IN THEIR B HORIZONS. THE SOLODIZED B HORIZONS OF THREE SOLIDIZED SOLONETZ SOILS WERE STUDIED AS EXAMPLES OF UNDESIRABLE STRUCTURE AND COMPARED WITH B HORIZONS OF ASSOCIATED CHESTNUT SOILS. A HIGH PERCENTAGE OF THE SILT AND CLAY WAS AGGREGATED IN BOTH GROUPS OF SOILS, BUT THE SOLONETZ SAMPLES HAD HIGHER DISPERSION RATIOS THAN THE CHESTNUT SAMPLES AND ALSO EXTREMELY LOW HYDRAULIC CONDUCTIVITY. BOTH GROUPS WERE NEUTRAL, NON-SALINE, AND HAD BETWEEN 1 AND 2 PERCENT ORGANIC MATTER. NONE OF THE SOLONTZ SAMPLES WERE SODIC, EXCHANGEABLE-SODIUM PERCENTAGE AVERAGED 8 PERCENT, BUT BOTH EXCHANGEABLE SODIUM AND EXCHANGEABLE MAGNESIUM WERE HIGHER THAN IN THE CHESTNUT SOILS. IT WAS SHOWN EXPERIMENTALLY THAT HIGH EXCHANGEABLE MAGNESIUM, AND EXCHANGEABLE SODIUM AT THE LEVELS FOUND IN THE SOLONTZ SAMPLES, WERE EACH CAPABLE OF INCREASING DISPERSION AND DECREASING PERMEABILITY OF THE SAMPLES. THESE SAMPLES DID NOT APPROACH THE CHESTNUT SOILS IN EITHER HYDRAULIC CONDUCTIVITY OR DISPERSION RATIO, REGARDLESS OF THE EXCHANGEABLE-CATION STATUS. CLAY CONTENT WAS HIGHER IN THE SOLONETZ SAMPLES, THUS HIGHER IN MONTMORILLONITE THAN COARSE CLAY. THIS DIFFERENCE IN MONTMORILLONITE CONTENT WAS SHOWN TO BE ONE OF THE CAUSES OF POOR PHYSICAL CONDITION IN THE B HORIZONS OF THESE SOLODIZED SOLONETZ SOILS. THIS WAS SHOWN BY THE EFFECT OF POTASSIUM TREATMENT ON MONTMORILLONITE AND ILLITE CONTENT AND ON HYDRAULIC CONDUCTIVITY AND DISPERSION RATIO. PEDS FROM THE SOLONETZ SAMPLES HAD SOMEWHAT LESS PORE SPACE THAN PEDS FROM CHESTNUT SOILS. THIS DIFFERENCE, TOGETHER WITH DIFFERENCES IN THE SWELLING PROPERTIES OF THE CLAYS, GAVE RISE TO THREE TIMES AS MUCH SWELLING IN THE SOLONTZ PEDS. THIS HIGH DEGREE OF SWELLING WAS CONCLUDED TO BE A MAJOR FACTOR IN THE LOW PERMEABILITY OF THE SOLONETZ HORIZONS AND PARTIALLY RESPONSIBLE FOR THE LOWER WATER STABILITY OF THEIR AGGREGATES.

  • Supplemental Notes:
    • Vol 102, No 1, PP 46-52, 1 FIG, 5 TAB, 18 REF
  • Authors:
    • Klages, M G
  • Publication Date: 1966-7

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  • Accession Number: 00237357
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 5 1994 12:00AM