salinity

I’ve written about the rapid change in soil pH that can occur in sand rootzones, especially when turf is grown in a tropical climate. That potential for soil pH and other soil parameters to change substantially is one of the reasons I recommend annual testing of turf grown in sand rootzones.

Here are three primary things to be concerned with when considering soil and water: salinity, the sodium hazard, and nutrient deficiencies. I explain solutions for each of these problems in this post, which was originally a handout for a seminar I gave on this topic some years ago.

This photo illustrates two things about salinity problems. First, the salinity stress is most evident in the low areas, because the salts drain with the water. Second—and this one can be counterintuitive at first—the solution to an irrigation water salinity problem is to add even more1 of that “bad” water as irrigation.

When this question arrived, I thought I could respond by showing a blog post I’d written in the past with the answer. “What kind of adjustments would you recommend to do when trying to use the MLSN on a Calcareous sand green profile and irrigation with water saline water with 1500 ppm and Pure Dynasty Sea Shore Paspalum and pH 8?

Irrigation water quality, salinity, gypsum, and sodium—I’m not even going to mention the problems that bicarbonate doesn’t cause—are topics that are sure to stir up some discussion. I’m writing this to put links to a few old posts about sodium and salinity into one place, and to share excerpts from three recent conversations that might clarify some solutions, and the simplicity of the solutions, especially when dealing with turf growing in a sand rootzone.

I received this question about leaching salts from the rootzone: “I remember talking to you once before regarding flushing excess salts from the root zone and the application of gypsum or other calcium products before the flush and you telling me it was not necessary.

A correspondent wrote: I’m hoping to get your thoughts on something I came across today. I was discussing greens fertilising whilst at a friend’s course this morning. He went on to get his new toy, the […] He’s started to use the salinity level reading as an indicator to fertilise.

On sand putting greens, it is. The problem caused by sodium is a reduction in the downward movement of water in soils. This is caused by the deflocculation of clay in the soil.

1. Is water (or a saturated paste extractant, or mixing irrigation water with soil) a good way to look at soil nutrients? 2. What about two tests to look at “available” and “exchangeable” nutrients, is it good to look at both?

The short answer is no, so long as sufficient potassium (K) is present in the soil. Cisar et al. looked at Tifway bermudagrass performance when the soil contained high amounts of sodium (Na).