Results: Effect of clay and silt content in soil on K retention and release after addition of 1000 ppm K

  • K fixation in soils is strongly dependent on the silt and clay content
  • This becomes more important in soils which are strongly weathered and contain lesser amounts of silt and clay, such as red and lateritic soils
  • The fixation behaviour varies according to the content of illite and vermiculite in silt and clay fractions among the soils

Effect of Kaolinite content in soil on K retention and release after addition of 1 ppm K

Process Coef. of det.
r
Retention 0.85*
Release 0.81**
  • Kaolinite has specific adsorption sites which are independent of pH (Jensen, 1973)
  • Sieve mechanism of K fixation by amorphous materials in kaolinitic soils (Reeuwijk and Villiers, 1968; Barber, 1979)

<< back | home | next >>