SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/338693
Field Science www.stma.org July 2014 | SportsTurf 23 May 2012 issue about how to monitor; you can find article, "Is your turf under A-salt?" at www.sportsturfonline.com.) Adjust fertilizer source and/or reduce fertilization rates. If irrigation water contains excess soluble salts, send a water sample to a soil-testing lab for an irrigation water analysis. This analysis will help to determine the ions that are readily available from the water source. Using this data, the nutrients supplied by the fertilizer can be reduced to account for those readily available from irrigation water. If adjusting fertilizer nutrient levels is not an option, simply lower the rate at which the turfgrass is fertilized (if possible) to reduce excess salt presence in substrate/soil. Especially for soluble fertilizers, since they directly contribute to higher salt levels, apply- ing a lower rate with more frequency may also assist in ensuring that the soil is not overloaded with salt at any given time. Apply an amendment. This is done ONLY when either (a) the water source is pure, or (b) Na has been identified as the main salt constituent. The most common amendment used is gypsum. It can be applied in a granular form or injected in line into the irrigation water. Gypsum replaces Na with Ca. Other Ca sources work as well. If adequate Ca is available in the soil, applying acid to reduce the soil pH and release the Ca may be effective. Look for a future article focusing on amendments. Contact the authors if you need assistance on determining options. Blend "salty" with clean water. Whatever the source of high EC in water, if there is another source (whether municipal, pond, well, etc.) that can be used to dilute the "salty" water, use it to decrease the salt levels and reduce plant stress attributed to high substrate EC. For most turfgrasses, the target is to reduce to ≤ 2 dS m-1. Contact the authors for additional help. Change to a different water source entirely. If EC readings of current water are so high that it is not feasible to continue using a particular source, find an alternative source. Install a reverse osmosis system. If no alternative or mixing source of water is available and growing turfgrasses at this particu- lar location is critical, a reverse osmosis system may be the most viable method for producing quality water that can be used for irrigation purposes. These systems have improved greatly in the last few years; however, they tend to be expensive and the wastewater, a salt-rich brine, must be disposed of. With most reverse osmosis systems, once the water has been cleansed (desalinated), Ca and Mg are added back and or the water is blended with rain fed/storm water so the water is not too pure. The salinity reduction strategies above can help reduce and/or alleviate salt stress, but keep in mind that each strategy is only as effective as the monitoring data from which you make your manage- ment decisions. ■ Dara M. Park, Ph.D. is an assistant professor, turfgrass, soil & water quality at Clemson University. Dr. White is the nursery extension specialist at Clemson.