Cation Exchange Modelling

The cation exchange capacity (CEC) is the capacity of the soil to retain, adsorb and exchange cations. This capacity is variable depending on the organic matter content, pHMoreover, for similar exchange capacities, the intensity of the exchange varies according to the chemical composition of the water that passes through the different horizons and the pore water it encounters on its way, because the exchange takes place with the aim of achieving chemical equilibrium between the soil pore water and the irrigation water. In other words, the greater the difference between the two waters, the greater the exchange. Therefore, for similar cation exchange capacities in a soil profile, a more intense exchange takes place in the shallower horizons than in the lower horizons because the differences are greater between these waters; in the lower horizon the irrigation water has already begun to equilibrate with the pore water of the upper horizon and therefore the differences between both waters decrease as the depth increases, and so does the cation exchange.

The intensity of cation exchange of the different soil horizons is a function of the chemical differences between the soil pore water and the irrigation water that penetrates the soil.

The modelling of these phenomena can be carried out using hydrogeology software applied to sports surfaces, taking into account the chemical analysis of irrigation water and soil. Thus, Tiloom offers the modelling of the cation exchange that can occur in different soils irrigated with different waters, even modelling the temperature or CO2 production rates in the different seasons of the year.

See figure for an example of modelling two different soil profiles at a temperature of 8 °C (profile A from 0 to 10 cm and profile B from 10 to 20 cm, both with a soil atmosphere of 1% in soil CO2 content.

It is possible to quantify the exchange that takes place (a total of 10 times more milliequivalents/kg of soil in the upper horizon than in the lower horizon in this particular case), as well as to know which cations are adsorbed or desorbed.

Therefore, depending on the different irrigation waters and the nutritional or saline content of the soil, the exchanges vary and can even be reversed in the different soil profiles.

If you know exactly what is happening on your floor, you will be able to treat it correctly. Leave nothing to improvisation. Call Tiloom now and your agronomic management will be significantly profitable.