El Nino Rains Helping Salinity Issues, Some Soils Hard to Sample
El Nino rains should help with the salinity problems some growers have seen during this drought and experts say some soils can be hard to sample correctly.
Salinity issues have risen during this prolonged drought and growers must pay attention to levels in the water they use as well as their soil. Cooperative Extension Pomology Farm Advisor David Doll says damage can be done to a tree before visual signs appear.
Doll spoke at the Almond Board of California Conference in December and showed growers how some soils can be a challenge to sample.
Salinity Management in Fine Textured Soils
From the Almond Doctor: Starting with the soil, we often use the term cation exchange capacity (CEC), which is the amount of cations (positively-charged ions like sodium, magnesium, calcium, potassium, etc.) that can bind to the soil particle surface. In fine textured soils across the State, CEC values can be very high, with values ranging between 15-40 meq/100 g of soil. Generally, sandy loams are in the teens through 20s, and silts and clays are in the 30s to 40s. This CEC 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 salt exposure to the roots of the tree. Read more from The Almond Doctor blog.