You receive a lab analysis (as shown in the accompanying table) of the exchangeable cations in alkaline soils from two sites you are managing.
Calculate for both sites:
1. CEC of the soil (2 mark)
2. exchangeable sodium percentage (ESP) (1 mark)
3. sodium adsorption ratio (SAR) (1 mark)
4. which site(s) is/are at most risk (if any) for sodicity issues? (2 mark)
TABLE 1. Exchangeable cations in alkaline soils from Sites A and B. Values are in cmolc kg
Site Na K Mg Ca
A 3.5 2.3 1.8 2.9
B 3.2 2.0 1.7 2.1