AUTHORS NOTE: The following article discusses salinity management considerations for SANDY SOILS (e.g. sands, loamy sands). A follow up post will be made for finer texture soils (loams, silts, and clays). For the most part, this article describes issues with the EAST SIDE of the San Joaquin Valley. NOT ALL SOILS ARE THE SAME. Please note that the following guidelines may need site-specific adjustments. During low rainfall years, salt burn often shows up in sandy soils. This salt burn is a combination of accumulation of sodium within the soil, the use of well water, and the low exchange capacity of the soil. Starting with the soil, we often use the term cation exchange capacity (CEC) which is the amount of cations (positive charged ions like sodium, magnesium, calcium, potassium, etc.) that can bind to the soil particle surface. In the sandier areas on the east side of the San Joaquin Valley, CEC values can be quite low, with values less than 10 meq/100 g of soil. To put that in perspective, sandy loams are in the teens through 20s, silts and clays are in the 30s to 40s. This value is important as it indicates the amount of cations the soil particles can hold. The higher the CEC, the more cations that stick to the soil, preventing them from entering the soil water (soil water is the amount of water that is held between soil particles – it is what the tree drinks), reducing exposure to the roots of the tree. Regardless of the CEC, once the soil is saturated with cations, the excess will stay within the soil water. As the soil salinity increases, the tree’s roots have a greater exposure impacting them by affecting the osmotic movement of water (e.g. essentially making the tree work harder for water) and  eventual toxicity.