Making the Right SpendingDecisions When Tackling Soil andWater Quality ProblemsIssues to consider before investing the dollars.BY PATRICK J. GROSS

Salt- and sodium-affected soil is a major obstacle to producing top-quality turfgrass conditions. Thewhite powder on the surface of the soil in the above photograph is not snow - it is salt!

Doyou want to be on the.. cutting edge of golf course

maintenance technology? Afew golf courses are using an excitingnew product, and they have neverlooked better! Here is what this product .will do for you:• It will make water wetter .• Reduce irrigation by 10% to 40% .• Save fertilizer .• Reduce the need for chemical

applications .• Reduce the need to aerify .• Control algae in your lakes .• Control fungus, mildew, and root rot .• Eliminate black layer .• Improve drainage.

Does the above scenario sound toogood to be true? Most definitely, butsuperintendents fall prey to such out-rageous sales tactics and spend thou-sands of dollars of their employers'money in search of the magic productthat solves all their soil and water qualityproblems with little or no effort.

Soil and water are the two biggestresources that superintendents managein the production of high quality turf-grass. It makes sense that any efforts toimprove soil and water quality will havea corresponding positive effect on turfgrowth. Concerns are more prevalenttoday, given the fact that several newercourses are built on sites with adversesoil conditions and the increased use ofrecycled water or poor quality wellwater. It is only natural that superinten-dents are looking at ways to improvesoil and water quality. With so many

options, the question becomes whichproduct to choose.

ISTHERE A PROBLEM?Before jumping on the bandwagonwith the latest treatment device orproduct, it is important to analyze yoursituation to see if there is an actualproblem. Questions you may want toask include:• Are there signs of poor soil perme-ability or water ponding throughoutthe course?• Does your turf show salt stresssymptoms and decline?• Does your water or soil have a highpH that limits nutrient availability?

• Is the entire course affected or areproblems restricted to certain areas?

If you are convinced there may bea problem, the next step is to havean independent laboratory test thechemistry of the soil and water to seeif amendments or treatment devices arewarranted. The laboratory you chooseshould be experienced in evaluatingsaline and sodic conditions for soil andwater. While many of the same com-panies that manufacture products orequipment will offer to test your soiland water free of charge, it is best to usean independent labo(atory that doesnqt have a stake in selling you anything .Using such a laboratory insures that you

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Gypsum injectors are typieally used to treat sodie or saline-sodie soil conditions,water sources with high SAR,or very pure water sources.

are receiving unbiased information toform the basis for any future spendingdecisions. A few hundred dollars spentfor unbiased laboratory testing can savea golf course thousands of dollars inunnecessary equipment or ineffectiveproducts.

TREATMENT OPTIONSThe chemical evaluation of your soiland water quality will guide you towardthe best treatment options for yoursituation. The following sections pro-vide a brief overview of some optionsto improve soil and water quality atyour course.

BASIC AGRONOMICPROGRAMSSound cultural programs should be thebasis for treating problems associatedwith high salinity, which are the mostprevalent soil and water quality prob-lems observed in the arid Southwest.Soil tests typically show a high ECe(>4.0 dSm) and a low sodium hazard(ESP<15%). Controlling soil salinityrequires attention to the followingagrononuc programs:• Aeration.• Leaching.• Drainage.• Fertility.

The goal is to dilute the accumulatedsalt with extra water and move it downthrough the soil, away from sensitiveturf roots. A good irrigation systemwith proper distribution uniformity isessential to manage high salinity situ-ations. While it may seem easier toapply a promising new product to solvethe problem, very few products performas well as an aerifier in conjunctionwith good irrigation practices. Aerationand leaching also are critical programsthat must be employed for the treat-ment of sodic or saline-sodic soils.

GYPSUMGypsum is most often recommended totreat the following conditions:• Sodic or saline-sodic soil conditions(ESP> 15%).

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• Water with a high SAR (> 10) thatcontributes to poor water infiltrationand surface sealing.• Very pure water sources (ECw<0.5dS/m).

Gypsum can be surface applied ifthere are only marginal problems withsodium-affected soil or water. Forchronic problems, solution-gradegypsum can be mixed with water andinjected into the irrigation system. Thefollowing is a general estimate of thecost to purchase and operate a gypsuminjection system:• Equipment cost: $7,000 to $15,000 ormore .• Solution-grade gypsum: $120 to$200 per ton.• Annual cost for gypsum: approxi-mately $10,000 to $20,000 per year ormore, depending on the recommendedapplication rate based on soil and watertests.

ACIDIFYING TREATMENTSAn acidifying amendment is typicallyrecommended for the followingsituations:• Sodium-affected soil with poorinfiltration (ESP>15%) where there isadequate free lime present in the soil.

• Water with a high adjusted SAR anda residual sodium carbonate (RSC)level greater than 1.25.

• Reducing the pH of the soil andwater.

There are several options for apply-ing acidifying amendments, includingsurface-applied sulfur, acidifying fertil-izers, the use of a sulfurous generator totreat water in the irrigation reservoir, orthe direct injection of sulfuric acid intothe irrigation mainline. The following isa general estimate of the cost to pur-chase and operate a sulfurous generator:

• Equipment cost: $12,000 to $16,000.

• Sulfur: $250 to $350 per ton.• Annual cost for sulfur: $3,000 to$5,000 or more per year, depending onthe volume of irrigation water used andthe amount of sulfur recommended bysoil and water tests.

The use of a sulfurous generator isgenerally considered simple and costeffective if it can be justified by soil andwater testing. A few issues to considerare the uniformity of mixing the acidi-fied water in the lake and the aestheticsof the generator, which produces smokeand is often placed in a visible locationon the shore of the irrigation lake.

The direct injection of sulfuric acid into the irrigation mainline from a nearby storage tank is anothermethod to introduce acidifyingamendments. The hazard of handling concentrated acid must beconsidered along with the need to provide adequate space at the pump station for the storage tankand access by delivery trucks.

Another option for acid treatment isthe direct injection of sulfuric acid intothe irrigation mainline. The following isa general estimate of the cost to pur-chase and operate an acid injectionsystem:• Equipment cost: $15,000 to $18,000.• Acid: $1.00 to $1.75 per gallon .• Annual cost for acid: $8,000 to$25,000 per year, depending on thevolume of irrigation water used and theamount of acid recommended by soiland water tests.

Direct injection of acid into theirrigation mainline improves the uni-formity of mixing, but there are safetyconcerns with handling concentratedsulfuric acid. The safety issue is oftenaddressed by using a sulfuric acid prod-uct that is mixed with urea, commonlyreferred to as N-phuric acid. Theacidification properties are the same,although the cost of the material isgenerally higher. The results achievedwith the use ofN-phuric acid are oftenmisleading because most people willnotice the nitrogen response and assume

it was the acid and not necessarily theurea. Other points to consider includeproviding adequate space at the irriga-tion pump station for acid storage tanksand injection equipment. The storage.tanks also must be accessible to deliverytrucks .

DO YOU NEED ANINJECTION SYSTEM?Before you invest in an expensiveinjection system, it is important to testthe chemical properties of the soil andwater to see if such a system is neces-sary. Surface applications of gypsum orsulfur in test plots also can be made aspreliminary treatments to evaluate thelong-term effectiveness of an amend-ment program. Consider the followingadvantages and disadvantages regardinginjection systems:

ADVANTAGES• Injection of amendments into theirrigation system reduces the dustassociated with granular applications.

• Reduced labor requirements forapplication.• Acid injection reduces the burnpotential on low-CEC soils.• Acid injection equipment also can beused to inject liquid fertilizers.

DISADVANTAGES• Liquid amendments are moreexpensive than dry products.• The initial expense of the equipmentand ongoing costs for repair andreplacement of parts.• Corrosion of irrigation equipment.• The hazard involved with handlingconcentrated acid.• The uniformity of the irrigation sys-tem is critical for accurate application.

OTHER OPTIONS FOR SOILAND WATER TREATMENTIn addition to injection systems and thesurface application of soil amendments,there are other avenues that can beexplored to address soil and waterquality problems, including:• The use of surfactants and soil wet-ting agents to treat localized dry spotsand to improve water infiltration wheresodium levels are not a concern .• Blending different water sources toimprove chemical properties and reducethe percentage of sodium and solublesalts.• Plumbing a separate irrigation lineto the greens to supply potable water,assuming the potable water quality isbetter than the irrigation source .• Planting salt-tolerant grasses.

Some golf courses have installedin-line pipe devices and other types ofwater treatment hardware in an effortto improve water quality and turf per-formance. The cost of such devices isoften very high ($40,000 to $50,000 ormore), and there is very little peer-reviewed scientific research to justifymanufacturer claims. It also is difficultto obectively evaluate these products inthe field since a large section of thecourse or the entire course is treated,leaving no opportunity for an untreatedcheck area for comparison. In such a

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The use of a sulfurous generator is one option to treat sodium-affected soil or irrigation water high in bicarbonates.A few issues to consider are the uniformity of mixing the acidified water in the lake and the aesthetics of the generator,which produces smoke and is often placed in a visible location on the shore of the lake.

situation, it is suggested for buyers toproceed with caution.

CONCLUSIONThe marketplace is full of productsaimed at improving soil and waterquality, and it is difficult for superinten-dents to decide which products wouldaid their situation. If your golf course isexperiencing difficult soil and waterquality issues, do yourself and youremployer a favor by taking thefollowing actions:• Obtain a thorough chemical analysisof your soil and water from an indepen-dent laboratory that has no stake inselling you any treatment products orequipment.

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• Purchase and read the book Salt-Affected Tuifgrass Sites - Assessment andManagement by Dr. Bob Carrow andDr. Ronny Duncan, which describesand explains the various soil and waterinteractions and provides a sound agro-nomic rationale for treatment options.• Take the GCSAA class on "ManagingSalt-Affected Turfgrass Sites" to enhanceyour knowledge of soil and water qualityproblems and their treatment.• Seek the advice of soil and waterquality experts to help evaluate yourtest results and offer unbiasedrecommendations .• Protect the interest of your employerwhen considering soil and water treat-ment options and spend the money as ifit were your own.

REFERENCESCarrow, R. N., R. R. Duncan. 1998. Salt-AffectedTuifirass Sites - Assessment and Management. AnnArbor Press, Chelsea, Mich.

Carrow, R. N., R. R. Duncan, M. Huck. 1999.Treating the Cause, Not the Symptoms. USGAGreen Section Record. 37(6):11-15.

Howard, H. E 1996.Acid - To Inject or NotInject. USGA Green Section Record. 34(1):12-14.

PAT GROSS is directorojthe USGA Green SectionSouthwest Region, wheresoil and water qualityissues are a major concern.