Examine the (Almost) Essentials: Sodium
While sodium might not be essential for every plant, there are a few species that require this element because of the way they process nitrogen. Corn, sorghum and sugarcane are the most common crops with documented sodium needs, which helps with osmosis to draw water into cells. But another reason sodium is not considered essential is that there are other elements, such as rubidium, that can serve the same purpose. A truly essential nutrient has no substitute, and a plant cannot properly grow and develop without it.
Sodium toxicity is a more common problem than sodium deficiency, given the amount of sodium in chemical fertilizers and pesticides, and runoff from winter ice removal on roads and sidewalks. Too much sodium can cause plant tissues to dry out. One unexpected source of sodium in soil, particularly for houseplants, is watering with water that has gone through a water softener.
If your soil test shows excessive salt levels, adding organic matter and improving drainage can reduce soil salinity. Our Organic Gypsum can also help. The calcium in the gypsum will bind to clay particles, releasing the sodium. The sodium will then leach out with a good rain or watering, literally washing away the excess salt from your soil.