Download Iowa Soil Clay Content Maps (gSSURGO)

Clay as a soil separate consists of mineral soil particles that are less than 0.002 mm in diameter. The estimated clay content of each soil layer is given as a percentage, by weight, of the soil material that is less than 2 mm in diameter. The amount and kind of clay affect the fertility and physical condition of the soil and the ability of the soil to adsorb cations and to retain moisture. They influence shrink-swell potential, saturated hydraulic conductivity (Ksat), plasticity, the ease of soil dispersion, and other soil properties. The amount and kind of clay in a soil also affect tillage and earth-moving operations. Most of the material is in one of three groups of clay minerals or a mixture of these clay minerals. The groups are kaolinite, smectite, and hydrous mica, the best known member of which is illite.

Download

Available Depths


  • 0 – 5 cm            • 5 – 20 cm
  • 0 – 20 cm          • 20 – 50 cm
  • 0 – 30 cm          • 50 – 100 cm
  • 0 – 100 cm        • 100 – 150 cm
  • 0 – 150 cm        • 150 – 200 cm
  • 0 – 200 cm
Spread the word

Leave a Reply