by bradley s. park, and dr. james a. murphy skin surface

14 SportsTurf | February 2011 www.sportsturfonline.com

FieldScience | By Bradley S. Park, and Dr. James A. Murphy

Soil used to construct a skin surface isreferred to as infield mix. Thus, soil selec-tion and management of skin surfaces willaffect playability. A high quality skin sur-face is smooth, uniform, and provides con-sistent footing and ball response; whereas apoor skin surface can result in errors byplayers fielding ground balls, player injury,and chronic puddling in rainy weather.

A high quality skin surface is often de-scribed as one that is moist and cork-like, asopposed to hard and dry; the surfaceshould allow players’ cleats to penetrate thesurface and leave an imprint with very littlesoil disturbance or displacement. The skinsurface should not give way (break loose)when players plant their feet to throw, fielda ball, or run. These characteristics arestrongly controlled by the physical proper-ties of the infield mix and its maintenance.

Physical properties of an infield mix arestrongly affected by its sand and fines (siltand clay) content. Maintenance of a skinsurface involves managing water (irrigationand tarping), dragging and grooming, andthe use of conditioners. Dragging andgrooming loosens, levels and smoothes theskin surface to maintain safety and playabil-ity. Conditioners are typically granular,clay-based materials used to maintainplayability over a range of weather (water)conditions.

SELECTING AN INFIELD MIXASTM (2007) suggests that infield

mixes consist of 60 to 81% sand with theremainder being comprised of silt, clay, andgravel (preferably none) according to theparticle size specifications. A 4- to 6-inchlayer of mix is placed above the subsoil andfinished to final grade. In cases where theinfield mix contains greater than 85% sand

and exhibits high internal permeabilityafter heavy compaction, the mix should beplaced above a gravel drainage blanket toimprove water retention and stability of theskin surface.

Mixes with less than 19% silt and clayare better suited for rainy climates due tobetter internal drainage; however, thesemixes will require more irrigation in dryperiods to minimize dust and provide afirm stable playing surface. In contrast,mixes with greater than 19% silt and claywill drain more slowly and retain morewater; hence, the need to irrigate (fre-quency) will be less. Mixes with > 19% siltand clay will also be more prone to com-pact and be difficult to loosen, especiallywhen dry.

Some field managers prefer skin surfacesthat contain a greater percentage of fines(silt and clay) compared to the ASTM rec-ommendation for infield mixes. An infieldmix should contain between 50 and 75%sand because mixes with > 75% sand canbecome too loose and are readily moved(displaced) during play or dragging leadingto high and low spots, as well as the forma-tion of lips at the skin-turf boundary. In-field mixes should not exceed 40 to 50%silt and clay because these materials can be-come compacted, reducing the ability ofthe surface to accept water, and therebylimiting the grounds manager’s ability to“soften” a hard skin surface with irrigation.[We] recommend infield mixes be com-prised of approximately 60% sand, 20%silt, and 20% clay.

Skin surfaces should be constructed witha finish grade that provides adequate sur-face drainage (water runoff ) away from andoff the skin due to the limited permeabilityof most infield mixes. Baseball and softball

skin surfaces should be designed with a fin-ish grade of 0.5 to 1.5% slope away fromthe center of the infield.

Baseball and softball fields designed intomulti–sport fields should surface drainwater away from the infield and skin sur-faces. Field designs that position skin sur-faces of infields at the lowest elevation canrender the baseball/softball field unplayablefor several days after rain.

The following design parameters willprovide reasonable skin surfaces for the ma-jority of municipal and board of educationbaseball and softball infields.

1) Excavate 4 to 6 inches of native soilfrom the site.

2) Match the subgrade to the finishgrade contours (ideally 1.0% slope awayfrom the middle of the infield) using laser-guided equipment.

3) Firm, if necessary, but do not overlycompact the subgrade (i.e. roll with a small[< 1 ton] pavement roller disengaging anyvibratory function); any internal drainagethat can be achieved through the subgradewill be beneficial.

4) Replace the excavated layer with 4 to6 inches of infield mix containing no morethan 70 to 80% sand (remainder silt andclay). Ideally, there should not be any gravelin the mix.

5) Use laser-guided equipment to finalgrade the skin surface to mimic the contourof the subgrade. This will ensure the correctcontouring required for proper surfacedrainage.

6) A calcined clay conditioner productcan be applied as a topdressing (0.25-inchor less) to the surface to create more consis-tent ball bounce and desirable sliding con-ditions.

SKIN SURFACE MANAGEMENT

Skin surface management is typically asmuch art as science and practices haveoften been handed down from one fieldmanager to the next. The skills of thegrounds manager are often a greater con-tributing factor to the playing quality ofskin surfaces than the infield mix itself.

Grounds managers must use practicesthat are appropriate for the specific field ormodify the field conditions to match a

Skin surface selection andmanagement for infield

THIS ARTICLE provides information on infield mix(soil) selection for use as baseball and softball skinsurfaces, as well as maintenance guidelines to provideuniform playing conditions.

SportsTurf 15www.stma.org

given maintenance program. While skinsurface management techniques may differfrom one grounds manager to the next,there are specific tasks that need to be per-formed to produce safe playing conditionson skin surfaces. These tasks include but arenot limited to watering, scarifying and drag-ging, leveling, lip removal and conditioning.

The frequency and intensity of thesetasks is strongly influenced by the particlesize distribution (sand, silt and gravel con-tent) of the infield mix.

WATER MANAGEMENTWater availability is probably the most

important factor affecting the overall per-formance of skin surfaces. The water con-tent of a skin surface affects both ball andplayer reaction. Water is needed to softenfine-textured infield mixes (high silt andclay content) and firm coarse-textured mixes(high sand content).

Field design should include water supplyto the skin surface.

A quick coupler (hose connection)

should be located approximately 6 feet be-hind the mound on a baseball field; thesafest and most logical place for the coupler.More involved irrigation designs include au-tomatic pop-up irrigation sprinklers tolightly water (syringe) skin surfaces.

Differences in the approach to wateringskin surfaces are attributable to water acces-sibility, budget, labor, climate, particle sizedistribution of the infield mix, and coachand player preferences. Irrigation water forskin surfaces and turfgrass is often unavail-able in the case of municipal fields. Con-versely, managers of professional fields often“flood” skin surfaces before a homestand,immediately after a game, before lunch ongame day, and conclude with a final lightwatering in between batting practice andpre-game activities.

Water held within a skin surface pro-duces the “corky” feel that players desire;water is often provided through irrigationafter games in addition to supplementalgame day irrigation dictated by weather.[We] recommend skin surfaces be deeply ir-

rigated at a rate that allows water to infil-trate slowly into the surface and be retainedfor a considerable amount of time. Caremust be taken to avoid overwatering areassurrounding skin surfaces.

INFIELD DRAGGINGAND GROOMING

Periodic scarification, leveling, andsmoothing of skin surfaces is required; thiscan be accomplished with commerciallypurchased grooming machines or con-structed drags which can be hand-pulled ortowed by a small tractor or utility vehicle.Scarification and leveling methods shouldproduce a thin (0.25-inch) loose layer or“cap” on the skin surface. This cap providesmore uniform ball bounce and roll and agood surface for sliding. Scarification of thislayer should not exceed 0.5-inch (too deep)otherwise traction (footing) will decreaseand ground balls can skid rather thanbounce. Scarification often involves drag-ging the skin surface with a nail-drag (orsimilar) to loosen the surface 0.25- to 0.5-


FieldScience

inch. This loosened material is used tolevel-out high and fill low spots, which de-creases the time to dry the surface after rain(puddles are reduced in size after leveling).After scarification and leveling, a steel dragor cocoa mat is often used to groom(smooth) the surface before play.

Proper infield dragging, leveling, andgrooming techniques maintain/improvesurface drainage, safety and playability ofskin surfaces. Improper techniques thatphysically move infield mix into turf willencourage the development of a lip. A “lip”is a mound or ridge at the boundary be-tween a skin surface and turf. Lips impedesurface water drainage off the skin surfaceas well as present unsafe playing conditions.Therefore, it is imperative that infield drag-ging and leveling along the perimeter 12inches or more of a skin surface be per-formed by hand in a direction that movessoil away from or along the skin-turfboundary, not toward the turf. Wind andwater erosion can also move infield mixinto border turf areas resulting in a lip.

Invariably, movement of infield mix intothe bordering turf does occur and routinecorrective practices should be used to re-duce lip development. Stiff-bristled broomsare often used to brush 6 to 8 inches of thebordering turf towards the skin surface.Blowers, irrigation hose spray and powerwashers have also been used successfully.

If allowed to develop, large lips requirecostly and time consuming methods to cor-rect. A sod cutter will be needed to removethe grass and buildup of infield mix fromthe lip along the skin surface-turfgrass bor-der. Repair of large lips may also requiresubstantial re-grading to re-establish an ac-ceptable grade along the skin surface andturf boundary area. Typically, the turf-skinboundary is re-established with sod.

Adding infield mix to “eliminate” a lip isa common mistake because this action ele-vates the skin surface relative to surround-ing turf, decreases playability and safety,and often stops surface drainage. Repeatedaddition of infield mix eventually results inmajor renovation work to fix these com-pounded infield problems. Renovation in-volves the “extra” infield mix being removedand re-grading to reset the proper infieldcontours. The turf-skin boundary can thenbe re-established with sod.

USE OF INFIELDCONDITIONERS

Conditioners are materials designed tobe spread on top of skin surfaces to improveplayability over a range of weather condi-tions. Calcined clay is one of the most com-monly used conditioners. Typicallymontmorillonite clay is fired at approxi-mately 1200F to form granules of calcinedclay that remain hard even when wet.

Conditioners are often used to soak-up ex-cess water after rain; finer-textured condition-ers work best for this purpose. Conditionersused for this purpose should be swept-up (re-moved) from the skin surface after play,stored and allowed to dry for re-use.

A 0.25-inch layer of conditioner can bespread (topdressed) evenly across the skinsurface to produce the loose cap describedpreviously. Using a granular conditioner asthe cap material rather than infield mixgenerally makes it easier to remove migratedmaterial from the turf boundary back ontothe skin surface and prevent the develop-ment of a lip.

Skin surface water retention is a functionof the amount of silt and clay in the infieldmix, not the amount of calcined clay on thesurface. Calcined clay applied to the skinsurface will often dry before the underlyinginfield mix resulting in some grounds man-agers applying unneeded irrigation water.Fine-textured infield mixes can be modifiedto react more like coarser-textured mixes byincorporating calcined clay. In contrast,coarser textured infield mixes would be lessaffected by adding calcined clay because ofthe similar particle sizes between the infieldmix and the conditioner. Thus, a particlesize analysis of the existing infield mix isnecessary when deciding whether to incor-porate a conditioner; the addition of cal-cined clay to a coarse-textured infield mixoften will not improve playability.

MOUNDS AND BATTER’S BOXES

Clayey soil or “bricks” (clay >35%) areused to construct a stable, wear resistantsurface for the “table” (the area behind andto the sides of the pitching rubber), landingarea of the pitcher’s mound, and the batter’sand catcher’s boxes around home plate. Theinstallation of a clayey soil often minimizesthe damage caused by a pitcher digging in

front of the rubber. Clayey soil should beplaced and compacted (hand tamper) about0.5-inch below the surface of the mound;infield mix is used to bring the area to finalgrade.

Particle size guidelines for an infield mixto be used in the construction of a skin sur-face range from 50 to 81% sand and 20 to50% silt and clay. Infield mixes that containgreater than 75% sand will require substan-tial irrigation to provide a firm and stableplaying surface during dry weather. Con-versely, infield mixes with less than 60%sand will be very firm when dry and irriga-tion will be needed to “soften” the skin sur-face for play.

Regardless of infield mix selection, skinsurfaces must be graded to provide surfacedrainage away from the infield (0.5 to 1.5%slope). It is also important to provide a watersource to irrigate the skin surface. If irriga-tion is not available, playability of a skin sur-face will be less than optimum duringdrought. Grooming methods are needed toproduce a uniform 0.25- to 0.5-inch capover the skin surface and preventative main-tenance is necessary to minimize lip develop-ment. Lips along skin surface perimeterspresent a hazardous condition and requirecostly, time consuming renovation work.

Conditioners can be applied (top-dressed) to skin surfaces to act as the cap;finer-textured conditioners can improveplayability during rainy conditions. Addi-tionally, conditioners can be incorporatedinto finer-textured infield mixes to improvesurface hardness and increase permeability.A particle size analysis should be performedon the conditioner and infield mix to deter-mine compatibility before incorporatingconditioner into the infield mix.

Pitcher’s mounds and the batter’s andcatcher’s boxes should be constructed withclayey soil or “bricks” containing > 35% clayto provide the stability, traction and durabil-ity needed in these high traffic areas. ■

Bradley S. Park is sports turf research andeducation coordinator at Rutgers University;Dr. James A. Murphy is extension specialist inturfgrass management at Rutgers. This mate-rial is online at http://www.cpe.rutgers.edu/brochures/pdfs/Skin-Surface-Selection-and-Management-for-Baseball-and-Softball-In-fields.pdf.


FieldScience | INFIELD SKIN PACKAGE

ERIC BLANTON, Reno AcesI have Gail Materials Collegiate blend infield mix. It con-

sists of a 60% sand/20% clay/20% silt mixture. It was cho-sen due to its high clay and silt content and NO cindercontent. It holds together very nicely with very little cleatmarks after games. Gail Materials has continuously tried tomake their products better no matter what outcomes theyhave. They are a company that strives to be the best and thatalso was another reason I chose their product.

GEORGE MARSHALL, Stetson UniversityHere at Stetson University in Florida we use a clay field

approximately 6 to 8 inches deep on a sand base. We mix inwith it Turface Pro League Red that serves as our playingsurface. We laser grade the infield annually in the off season,and will do it twice if necessary depending on the rainy sea-son. Usually after laser grading we will add around 1 to 11/2 tons of Turface and play with it after that to get it to ourliking. We try and aerate with our Toro aerator a coupletimes a year to aide in drainage and fight compaction.

LARRY DIVITO, Minnesota TwinsOur infield mix is from Natural Sand in Slippery Rock,

PA. Grant McKnight is the owner there and he is the one whoengineered this infield mix. It is somewhat similar to what theMets used for their installation at Citi Field. Bill Deacon gaveme some great anecdotal evidence of its performance. As forthe blend, I would leave it to Grant to discuss. (see p. 22)

DAN DOUGLAS, Reading PhilliesInfield mixes in general have improved dramatically in

the past 25 years. Suppliers are now producing much cleaner

products and are more conscien-tious of the makeup of their mixes.There are also a lot more choices ofamendments. Whether a mix isloose, tight, dry, sticky or just anunappealing color, there is anamendment available to correct theproblem. In most cases, I recom-mend finding a fairly local supplierof infield mix (to save on truckingcosts) and changing any character-istics of the mix you don’t like withamendments.

The infield mix at FirstEnergyStadium in Reading is a combina-tion of Professional Diamond-Tex(50% sand/32% silt/18% clay) andamendments. Professional Dia-mond-Tex is tan in color, dries outquickly, does not get sticky whenwet and, notably, is produced only30 miles away by Martin Lime-stone.

The infield skin is renovated in

March when we: add new infieldmix, if needed, to help meet grade;Stabilizer is applied; the top 2inches are tilled and the infield skinis laser graded and rolled. A top-dressing combination of Turface ProLeague and Diamond Pro VitrifiedInfield Conditioner is maintainedduring the playing season. Theamendments have aided in overallmoisture management, footing, ballbounce and aesthetics of the infieldat FirstEnergy Stadium.

JIM WIGGINS, Tomball (TX) ISD

We just recently rebuilt bothour softball and baseball infields asboth were in dire need of an over-haul from the bottom up. Weended up taking about 4 inchesout of the baseball field and 2inches out of softball. Starting withthe new subgrade of 60/40 sandclay mixture we had blended, thecontractor, 4E Turf Services, andthen began the compacting andlaser work on the subgrade. Bothfields had Diamond Pro VitrifiedRed added as the new topdressingand then rolled and nailed multi-ple times to achieve our finishedproduct. After 10 years of amend-ing and working on our fields wewere able to finally redo both fieldsand are completely satisfied withour finished product.

In the past we have used Klaconand Turface as infield conditionersand have used and still use Klawogmound and home plate clay forthose areas. Getting used to thenew vitrified product compared toour calcined products will be a newlearning tool for us. I was comfort-able with my Klacon and Turfaceproducts, and still have them in our

What’s your infield mix?Editor’s note: We asked some veteran infield skin managers about their infield mixes and why theychose that combination and/or products:

infield mix If there are 1 or 2 crew members, working on four ormore fields every day, the infield mix will need a largersand content as watering and drying will not be able tobe maintained by the grounds crew.

baselines, mound and home plate areas onthe baseball field. I feel water managementwill become even more important now withthis new conditioner, but look forward tothe new challenges this may bring.

During the redo portions of both fieldsand with Rain Bird’s help, we added newFalcon high speed rotors to both infields.These dirt zone sprinklers have been timesavers for us over the years. We finished offthe redo’s by adding a quarter-inch of sandtopdressing to both fields. Bring on the sea-sons which start in the middle of Januaryhere in Texas!

CRAIG SCHLENDER,Ball Diamond Fine Sports Turf

I would have to say my favorite infieldmix would be a 60% sand/40% clay siltmix, 6 inches deep, incorporated with 6-8tons of calcined clay, on a regulation base-ball field, with 1 ½ to 2 tons of calcinedclay topdressing. I prefer the calcined clayamendments for good moisture holdingability on hot, dry days and the wicking

ability on rainy, wet days. The addition ofcalcined clay on very wet days, used as adrying agent, doesn’t change the mix orcolor in the future. The silt and clay pro-vide a high quality, solid base for spikes toget good traction.

As a field manager, I like a higher clay,silt content with the ability to keep a highmoisture content in the mix so it has a verysolid, firm base feel; 60% sand, 40% clayon days with rain approaching, backing offon water, so that it will wick more moisturewhen the rain falls.

As a consultant, I try to prescribe a mixsuited to the manpower of the groundscrew staff. If there are 1 or 2 crew mem-bers, working on four or more fields everyday, the infield mix will need a larger sandcontent as watering and drying will not beable to be maintained by the grounds crew.The mix will stay softer when dry and willbe more playable when wet. I still like to seecalcined clay amended to the mix. A 70%sand, 30% clay, silt mix works well for arecreational mix.

On all fields, surface drainage and avail-able water is the most important part of agood infield. On high-use complexes wheretime is a factor of maintaining good mois-ture in the mix, I suggest the addition ofhigh out-put irrigation heads, so water canbe added at night or early morning. Thisshould be set up with an automatic shut offshould a rain storm show up.

Whatever the mix, if the moisture con-tent is right, the mix will play pretty well. Iprefer a darker mix to minimize the glarefor players and fans. In Wisconsin, where Iconsult on many fields with low budgets,amending seems to be a considerable op-tion due to trucking costs. Additional fac-tors include true surface drainage, ability towater enough and normally the addition ofcalcined clay.

Some fields are more than 1% slope dueto various reasons, and in these circum-stances, I will use a higher clay content andvitrified clay as a topdress, as it will stay putbetter because it is denser but wicks lesswater. ■



FieldScience | INFIELD SKIN PACKAGE

TOM BURNS,TXI Diamond Pro

This is a very difficult question to answer becauseso many factors need to be considered. First, deter-mine what you are trying to change. Is the field toohard or too loose? Then I would get my infield mix an-alyzed and use the results to determine if I want to ren-ovate or replace it. Next, you have to ask yourself whatyou can afford to do. Often times we can make im-provements by amending the mix with a different tex-tured soil or a manufactured soil amendment. Soiltesting can determine what to use and in what vol-umes.

Next I would look at the grade. Do I have theproper fall to allow the skin to drain? Do I need to addmore infield mix? Are the lips properly maintained?Many times the skin looks to be low when in fact thegrass edge is too high. A little bit of daily maintenanceon the lip can be a mini-renovation in itself.

Be sure to do an assessment of your maintenanceprogram and be honest with yourself. A less-than-idealmix can still perform well with a good managementprogram while a great mix will not perform as well if itis not managed properly. Be honest with your expecta-tions and factor in your limitations (financial and lo-gistical); only then will you be able to make the rightchoice.

CLAYTON HUBBS,Stabilizer Solutions

We receive infield samples from fields all over thecountry. The first question we ask is, “What is yourbiggest complaint?” Focusing on your biggest com-plaint usually alleviates smaller complaints. This maysound like an oversimplification, but most complaintsfall into three categories: too hard, too loose/soft, orpoor moisture management.

The next question to ask is: where is my infield mixright now? The answer to this question lies within aparticle size analysis. Typical infield mixes should becomposed of 70% sand and 30% split between silt andclay for amateur fields and closer to 60/40 for profes-sional. Pay close attention to the coarseness of thesand. If the sand particles are very fine, then the mixmay be unstable despite the proper proportions of siltand clay. While these percentages are a good rule ofthumb, it will vary per region and parent material ofyour existing mix.

Understanding that parent material may provide in-sight into why the mix may not be performing, evenwith a satisfactory particle size distribution. If yourmix is dug from near a river bed, it may have too highof a silt over clay content, and the sand particles maybe more round than angular. Mixes that are derived

>> LASER-GRADING the infield at two-time STMA Softball Field of the Year at Stetson University, DeLand, FL.

Editor’s note: We asked some people who make infield skin products thisquestion: What factors should a turf manager consider if they want to improvetheir infield mix and/or skinned areas for this season and total renovation isnot an option?

Factors to considerwhen total infieldrenovation is not an option

from crushed stone may have the angular sand particles needed, butthe fines may not act like true silt and clay particles. Also, mixes withgood clay content may contain highly expansive clay particles thatcan wreak havoc during fluctuations from wet to dry and vice versa.

Now that I know where my infield mix is, can I adjust my main-tenance regimen to compensate? If your biggest complaint is a loosefield, then most likely your particle size analysis shows that you arelow on clay content. Instead of immediately adding clay content,you could first try increasing your watering and rolling regimen.

If your complaint is a field that is too hard, and the analysisshows high clay content, then you could increase watering and naildragging. Depending on your region and your silt content, increasedwatering may work against you, so make sure you don’t experimentduring a critical time of year. If nail dragging does not help, then trya different type of nail with greater weight added on top of the drag.

If changing your maintenance regimen does not provide sus-tained results, try amending your infield with sand, clay, or an in-field amendment. Take great caution when adding sand or claycontent. As mentioned before, sand should have a variety of particlesizes from fine to coarse. Too fine of sand may not have the desiredresults. The same goes for too coarse of sand. When adding clay con-tent, it is inevitable that you will add silt as well. Take care in notadding too much silt content as this will have the opposite effect. Itis recommended that you try a small test area first before addingsand or clay content over the entire field. Also, some fields may have

several different mixes added over the years. This may cause a layer-ing effect or pockets with varying particle size distributions. It is agood idea to survey different areas of the field to find out if thesepockets exist and make the proper adjustments.

Sometimes a safer route, adding infield amendments, can oftenmake a bigger impact. For hard or low drainage fields, conditionerssuch as calcined clay can be added. For fields that are unstable orhave poor moisture management, organic infield amendments canstabilize the infield. While manufacturers may recommend incorpo-rating amendments by mechanical blending (as we do), many timesthey can be nail dragged into the top couple of inches to provideshort term relief.

Another option to consider adding is a stabilized infield mix,which contains a stabilizing agent, most often organic infieldamendments, already pre-blended to work in conjunction with theproper amounts of sand, silt and clay. This can be an affordable op-tion to get you through the season by addressing just the surface.When considering this option, request more information from themanufacturer’s rep, if done incorrectly or with an unsuitable mix, alayering effect may occur.

The final option to consider without completely renovating afield is if the infield can be improved mechanically. Usually mechani-cal blending is used in conjunction with infield amendments, butcan be done without their use as well. Ripping and tilling is recom-mended once a year. Fines do sink to the bottom, your surface may



FieldScience

become too looseand drainage layersmay form. The sur-face soil particlesthemselves can alsobecome crushedfrom overuse, de-pending on the par-ent material of theinfield mix. Also,soil particles weatherand break downfrom exposure torain, snow, and sun.Ripping and tilling

once a year evenly blends soil particles, brings fresh soil particles tothe surface, and provides a good opportunity to level the infield byadding additional infield mix. Take caution not to till into your basematerial.

Like most things in life, infield mixes change and evolve through-out the years. This could occur from soil particles weathering andsinking, or from the addition of different mixes and amendments.Regardless of how it occurs, your mix is unique to your field. If youdon’t have the option to replace the mix with something more pre-dictable, then you must become the expert of your own mix. Thebest way to become the expert is to experiment and see how yourmix reacts to different variables.

GRANT MCKNIGHT, Natural Sand Company

In general, amendment projects tend to be about one-third thecost of renovation. The best way to predictably alter an infield skinwithout renovation is to follow the T.A.C.S. process: Test, Analyze,Compare and Solve.

Test. In order to improve existing material, it is important to“know what you have.” A soil test report with a particle analysis andsize distribution will reveal the cause of many poor-playing infields.For example, an infield with excessive silt content and low sand isoften described as playing “soft” and blows away over the course ofthe season.

There are a number of soil testing facilities across the country,some better than others. A reliable lab will be A2LA accredited.

Analyze. Analyzing the soil test report requires an understandingof the values it renders. The values on the soil test report include:sand content (overall), silt content, clay content. The size distribu-tion portion of the test shows the array and concentration of sandparticle sizes within the overall sand content.

Here are some basic principles:• Sand (overall). Provides structural stability for the infield mix

(think sand castle v. mud pies). • Silt and Clay. Clay provides moisture-retention for the infield

mix. Silt binds sand to clay. • Sand (size). The larger the sand, the better stability it will pro-

vide. Compare. A lack of specifications for infield soils has plagued this

industry. By studying our projects, we have found the following tobe true:

• Sand (overall). Should make up about 58-75% of the soil pro-file. Facilities with high-level maintenance will require less sand thanfields with volunteer maintenance.

• Silt and Clay. Combined, these values should not exceed 42%of the soil profile. The ideal ratio of silt to clay is 0.5 - 1.0 (silt toclay ratio = silt ÷ clay).

• Sand (size). The majority of the sand should fall between thevery coarse, coarse and medium sand ranges. Large concentrations offine and very fine sand indicate a lack of stability within the mix.

Solve. Determine what objectives need to be met (i.e., increasingsand content, decreasing silt to clay ratio, decreasing very fine sandcontent, etc.), then choose a material and a method for the amend-ment project.

It is very important to only use materials that identify their parti-cle makeup as verified by an independent soil test report. Engineeredsoils can be made into specific amendments for your project. Hereare some general guidelines:

To increase sand content: Use a soil with a sand content higherthan your current levels. Be sure that the amending soil does notcontain an abundance of fine and very fine sand, and that it has a siltto clay ratio of 0.5 - 1.0.

To decrease sand content: Use a soil with a sand content lowerthan your current levels. Be sure that the amending soil has a silt toclay ratio of 0.5 - 1.0.

To decrease silt to clay ratio: Using soil with more clay than siltwill always decrease the silt to clay ratio.

To decrease very fine sand content: Use a soil with minimalamounts of fine and very fine sand content. Be sure that the amend-ing soil has a silt to clay ratio of 0.5 - 1.0.

Amendments require incorporation into the existing soil profile.We recommend tilling to a depth of 2-3 inches for optimal blend-ing.

It is best to obtain another soil test report a few weeks after youramendment. The test report will reveal the changes made to the in-field skin profile. If further amendment is required, simply repeatthe T.A.C.S. process until you are satisfied with the test results.

JEFF LANGNER,Turface Athletics

The first step to improving an infield mix is to really understandthe kind of field you are working with. Every infield mix a combina-tion of sand, silt, and clay, plus any conditioners or additives incor-porated previously.

A field that is made of 100% sand would be loose, free flowing,and would drain well. When dry, however, a sandy field would pro-duce an unstable and unpredictable surface. With the right amountof water it will be firm and playable but forgiving, allowing for slid-ing and clean ball hops. Consider a beach where the water meets theshore. This area would make a very playable surface!

The other two components of soil, silt and clay, present contrast-ing characteristics to sand. Drainage is poor, creating puddles andslippery areas and causing rain-outs. When clay and silt get too drythey become rock hard, often cracking, creating dangerous hops and


possible injury. These issues can be greatly compounded when clayand silt get compacted due to heavy traffic. If kept at the right mois-ture level and properly maintained, however, clay and silt are verystable and wear resistant making them ideal for high impact areas.

A blend of the three components is necessary to attain a safe andplayable field that is easier to maintain. Knowing the makeup orcomposition of your existing infield mix will help determine howyou approach conditioning the field, and how you manage moistureon the field. Water management is critical to providing a safe andplayable field, no matter what mix of soil components are at play.

Calcined clay field conditioners help improve fields of any soilcomposition, because of their ability to reduce compaction and holdmoisture. For example, Turface has 74% internal pore space, mean-ing that there is significant space within the particles to hold air andwater. This keeps the field from becoming compacted, and promotesdrainage in times when the field endures heavy rains.

And calcined clays don’t just moisture but, similar to the effect ofa sponge, will release water back into the surface of the playing fieldover time as things dry out, preventing the hardened, cracked fieldsthat become such a burden in the hot summer months.

The multiple benefits of these products make them an effectiveaddition to any infield mix. The amount of product added to thefield should take into account not just the existing infield mix, butother factors such as the amount of traffic the field endures, theavailability of irrigation and the frequency of rainfall, the number offield managers able to maintain the field, along with the frequencyof field maintenance that takes place.

A field that doesn’t have the benefit of frequent watering, endureshigh traffic, or lacks routine maintenance will benefit from a slightlyhigher amount of calcined clay conditioner worked into the field.

For a full renovation on a 90-foot field (high school, college, orpro), for example, it is recommended that 8-10 tons of product beincorporated into a field at a 4-inch depth with a roto-till, resultingin about an 18% rate by volume. For fields with smaller budgets, 4 -5 tons could be incorporated into the top 2 inches using a nail drag,or even a ½ ton of product could be applied as a topdressing to atleast create a consistent playing surface.

There is a significant difference in the improvement one couldexpect to see from a field based on these varied methods of applica-tion, and amounts of product. Understanding your existing infieldmix and evaluating the external factors surrounding your field willhelp you better get started on a long-term maintenance program foryour field, so that even if immediate renovation isn’t a possibility,you can at least get the “ball rolling” on a better, more playable field.

LARA WEINSTOCK,Game Time Sports Systems

To improve an existing field you can add products to help im-prove infield surfaces at a nominal cost. Consider adding 4-8 tonsdepending on the size of the infield surface and the type of materialthe skinned surface is made of. The materials will need to be workedinto the top two inches of the existing infield dirt. Before anyamendments, consider edging the base paths and the arc, and reduceor eliminate lips if possible. Try to promote surface drainage by re-es-tablishing the grade of the skinned surface so it slopes toward grass

areas. Mechanical weed management and good routine groomingpractices will promote a safe playing surface, and a good visual expe-rience until funds and more time allow for a more extensive repair orupgrade.

DAVID A. CYGAN, Pro’s Choice

I always tell prospective customers they should think of soil con-ditioners as the icing on a cake. Some field managers think that youcan dramatically change an infield with conditioners. While condi-tioners will improve any infield, the best results occur when condi-tioners are added to soils consisting of sand, silt, and clay.

The amount of conditioners will vary depending on what iswrong with the field. If drainage is an issue, more material would beneeded. For example a high school or college field with 90-foot basepaths and poor drainage might require 10-12 tons of conditioner. Afield that is hard and compacted can usually be helped with 6-8 tonsof conditioners.

Note, when I refer to conditioners I specifically mean “MONT-MORRILLITE” clays. These have been the industry standard since1941. These types of clay are heat treated and are actually turnedinto a ceramic sponge. They are the only mineral that can absorb ex-cess water, hold it, and release it when conditions become dry. Theydo all this while maintaining their particle size, and they continueworking year after year. ■


FieldScience

cover the fields quickly. By the thirdweek of the fall season the weather pat-terns became favorable and we tookadvantage of welcome rain storms.

ST: What do you plan on doing inthe spring to continuing solving theproblem?

Cornelius: From our experience wewill attack the fields as early as possi-ble. The cold weather has set in fasterthis year [Dec. 10] so the extra workthat was done earlier in the fall willhopefully pay off. We have yet to makea decision on whether we will be usingany grow tarps and with the earlybelow freezing temperatures we mayhave missed that boat.

Our strength unlike most hasproven to be in our educating the endusers on field maintenance, field careand do’s and don’ts. Once you educateand you communicate your plans andgoals (providing they the end uses ben-efit as well) to them and you have aproven record it works it makes deal-ing with the extremes and the un-knowns much easier.

IOWAST: What is or was your worst

problem this year due to the weather?Chris Schlosser, Iowa Cubs: I am

not sure what our worst problemwas—either the record snowfall andamount of time it covered the turf anda little snow mold problem in thespring, or one of the wettest years inhistory combined with heat, humidityand disease that occurred because ofthe constant rainfall and not beingable to dry out completely.

These historic amounts of moistureled to a root problem of shallowing upand all our chemical applications neverlasted for the proper intervals. The last

PENNSYLVANIASportsTurf: What is or was your worst

problem this year due to the weather?James F. Cornelius, CSFM, West Chester

Area SD: Our worst problem was the extremeweather pattern; periods of either too muchrain or lack of rain with hot dry weatherplayed havoc on the athletic field turf. In theNortheast we dealt with high humidity andcool nights that provided the perfect environ-ment for diseases.

ST: What did you do last fall (or are doingnow) to solve the problem?

Cornelius: Knowing past history and mak-ing the correct or almost-correct guesses of fu-ture weather patterns was our biggest tool. InFall 2009 we began our aeration programmuch earlier, we aerated more than usual, wefed our turf higher amount of slow release fer-tilizers and we over seeded all the fields heav-ier than ever, applying over 71,000 pounds ofseed in order to thicken the turf and provide

ample seed to reduce late season wear areasfrom the end users.

In the spring of 2010 we aggressively top-dressed, applied more fertilizer and seed. Dueto the users’ schedules we were limited to irri-gation until the middle of June when we wereable to deep water the fields on a rotatingbasis in order to prevent an early dormancy.

Around the beginning of July we backedoff the irrigation to allow the fields to go dor-mant during the high stress period and edu-cated our users on protecting the turf fromcleat injury, moving around the field areas toreduce wear areas and where possible we shutdown fields and moved users to less significantfields at our elementary schools.

In the fall of 2010 we overseeded, appliedfertilizers, and with the help of our users whoconsistently applied seed provided to goalmouth areas, filled divots, moved daily warmup routines around the field and more heavyaeration and deep slicing, we were able to re-

Recovering turffrom severe weatherEditor’s note: This is a report from several regions around the country on how turf managershandle their turf in the wake of some severe weather in 2010.

Up here in the Pacific Northwest the 2010 summer was veryuneventful, almost normal. We had cooler then average temps

and average rainfall.-Jason Moore, CSFM, Tualatin Hills Park & Rec, Beaverton, OR

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problem was the amount of time the tarpwas covering the field. The rain patternswere so incredible you had to start planningdays in advance of an upcoming homestandto make sure you were covered because ofrain and dry time leading up to and ingames. We (the turf and grounds crew) justtried to survive and keep our sanity.

ST: What did you do last fall (or aredoing now) to solve the problem?

Schlosser: After the tough year the rainsshut off for pretty much all fall and we wereable to stress the field and drive some rootsdown with normal practices. I did put oneliquid snow mold application down andfollowed it up with a granular PCNB be-fore we froze. Just trying to get a little moreresidual in the plant to last if we have an-other winter like last.

ST: What do you plan on doing in thespring to continuing solving the problem?

Schlosser: For 2011I am planning forthe worst case scenario happeningagain. After the schedule was released we

are trying to limit outside events and gamesso we have enough time to do our culturalpractices, which were limited because of ahigh number of events last year. For chemi-cal applications we are working them inmore often and cutting down the intervalcycle. We are usually on a 14-day preventiveprogram and now I am looking at a 10-daybecause the breakthrough last occurred onthat 9th or 10th day. Overall we didn’t haveany turf loss; what was damaged grew outof it and came back with normal practices.

OKLAHOMAST: What is or was your worst problem

this year due to the weather?Jeff Salmond, CSFM: The only prob-

lem was dealing with drought and notbeing able to water during the day. Any wa-tering during the day, for example on abaseball infield, was done during lunchbreaks, which is equivalent to a slight sy-ringe. Throughout the whole summer, wehad camps and clinics during the day and

in the evenings because of the heat. Theonly time we were able to get sufficientwater was at night. But we could not watertoo heavy as to make it wet for activities thenext day. We also were not able to performas many cultural practices, especially verti-cutting and aerification.

ST: What did you do last fall (or aredoing right now) to solve the problem?

Salmond: We did more multiple needle-type aerifications, gypsum applications anda little heavier watering.

ST: What do you plan on doing in thespring to continuing solving the problem?

Salmond: We plan to use growth blan-kets to promote and initiate earlier turfgrassgrowth and build up moisture in our root-zones in anticipation of a warmer, drierspring and cooler, wetter summer. We alsohope to change up any consistent wear pat-terns for turfgrass recovery. ■

by bradley s. park, and dr. james a. murphy skin surface

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