Most high value crops are sensitive to irrigation water quality. So, if you are renting an irrigation system and don't have a water quality test or you are going to irrigate a high value crop such as potatoes or carrots, it is especially important to test the water. The TDS is in indication of the amount of dissolved salts in the water. The SAR is a measure of the relative amount of sodium in the water. For many soils, an irrigation water with an SAR greater than 6 can cause soil crusting problems.
Many private laboratories can do water testing.
Sharon D. Anderson, Director, Fargo, North Dakota. Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914.