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Soil and Water Testing for Turfgrass: valuable tool, or absurd pretense?

Glaring errors on soil and water test reports are a source of frustration and concern. Soil nutrient analyses (soil tests) and irrigation water analyses (water tests) can be a valuable tool, but sometimes they are more like a charade. Errors on these reports are more common than one might think, although I expect that a number of report templates will be changed after reading this.  

Error-phosphorousHere are the top 3 errors I've commonly found on soil and/or water reports. Surprisingly, one can find these errors on reports from multiple laboratories, from multiple companies.

1. The misspelling of phosphorus as phosphorous. Phosphorous is an adjective and is not the element P, which is spelled phosphorus. Phosphorous, in fact, means phosphorescent, glowing. How much can we trust the results if one of the major macronutrients is not spelled correctly? Might there be other errors in the report? 

2. Sodium adsorbtion ratio. Wrong. Sodium absorption ratio. Also wrong. Let's try sodium adsorption ratio. That's right. How is it that laboratories can misspell such an important irrigation water quality parameter? It is not like there is an option of how to spell this. It is either right or wrong. Sodium adsorption ratio (SAR) is one of the most important parameters to look at when evaluating water for irrigation suitability. Sending out reports and water quality guides with such errors makes one wonder about other possible errors in the report.

3. How about irrigation water tests that don't report SAR? That is not very useful at all. The two most important parameters on an irrigation water suitability test are the sodium adsorption ratio (SAR) and the electrical conductivity (EC). The total dissolved solids (TDS) are an analog of EC. If you get a water report without SAR, or without EC, you are not getting the data you need. 

Then, of course, there is the really big error, which I won't write about in detail here, but for turfgrass, the classification of soils as being high, optimal, or deficient in a particular element is usually quite far from correct. I don't know exactly what is correct, but the best approximations I know of are the Minimum Levels for Sustainable Nutrition (MLSN) guidelines. I've been working on these with Dr. Larry Stowell from PACE Turf over the past year, and this ongoing project aims to refine turfgrass nutritional guidelines. If you are really interested in this, you can read more about it here.

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