What are guidelines for the suitability of irrigation water quality relative to soil dispersion, crusting, and swelling?
Table 2 illustrates guidelines for irrigation water quality relative to risk of soil dispersion, crusting, and swelling. How to use this table: the three pieces of information you will need are: 1) the amount and type of clay in your soil; 2) the salinity (EC) or TDS (mg/L) of your irrigation water; and 3) the SAR of your irrigation water. If your soil has less than 30% clay or does not contain a swelling-type clay, risk of dispersion, crusting, and swelling caused by irrigation water is minimal. To determine risk, first select the SAR range which applies to your irrigation water, i.e., 0-3, 3-6, or 6-12. Within that range, select the EC or TDS that applies to your irrigation water. Then read across the row for the SAR x EC or TDS combination to the far right column, which indicates the risk of soil dispersion, crusting and/or swelling.
