Mowing Co$t BreakdownMike BladonGrounds Dept., University of Guelph

Grass cutting is the most time con-suming of the maintenance

programs conducted by a sports turf man-ager and the most important from theaspect of the appearance of a turf area.Proper selection of the mowing equip-ment is essential for success. Purchasingdecisions are often reached withoutknowing the long term effect the equip-ment may have on your budget. Thisarticle addresses some of the factors youshould consider before signing the pur-chase order.

Industry people say the total cost peracre should be the determinate to be em-ployed in equipment selection. The totalcost per acre is made up of several com-ponents; each will be discussed sepa-rately with an estimate of how much eachcomponent contributes to the total cost.

The Purchase Price(10% of the cost per acre)

A wide choice of models and designsare available. They may be classified intotwo basic cutting actions - shear or im-pact - and four systems - reel, rotary,sickle and vertical. The desired height ofcut, the degree of contour following re-quired (wooded, rough, swampy, hilly orformal), the type of vegetation, the de-sired finished appearance, each have ad-vantages and limitations which should beconsidered.

The first consideration, however, is theproductivity of the unit - the rate at whichwork is performed; usually in acres perhour. Published specifications generallyindicate straight ahead mowing at aver-age speed with no allowance for stops,overlaps, turns, trimming or ma-noeuvring of any kind.

In order to save money, but not neces-sarily cut capital costs, the unit mustminimize time and labour costs: Does theunit have engine power to cut heavygrasses at high ground speed?; have trim-ming capacity?; float to avoid scalping?;have adequate traction and side hill sta-bility?; have a sturdy frame construe-

tion?; provide operator comfort such assufficient leg room, comfortable seats,automotive speed control devices to less-en operator fatigue?

Maintenance Costs(15% of the cost per acre)

Depreciation, accelerated by new prod-uct lines, creates obsolescence. As a re-sult there is little need to save oldmachines, even parts. Duration of thewarranty and availability of parts andservice for a new machine should be con-sidered. Down time costs money.

During an eight year period , undernormal conditions, 100% of the purchaseprice may be spent on the maintenance ofa unit. Under severe conditions, as littleas three to four years is required. Twokinds of maintenance are a given - 1) oilchanges, blade sharpening, motor tune-ups and 2) engine replacement. Recordsare useful in determining the costs on aper hour basis and may serve as a basisfor repurchasing a similar unit.

Remember properly adjusted belts,chains, bearings, and shafts will reducefriction, resulting in more power formore output per acre.hour.

Fuel Costs(9% of cost per acre)

Fuel costs equal fuel consumption Xfuel prices. Over the life time of a ma-chine the latter may change drasticallyand lead to an early consideration of re-placement.

The type of machine should be matchedto the application. Purchase the largestmachine for the job that is practical.Larger mowers require less man hoursper acre. Generally they are built forheavy duty use, are equipped with watercooled engines which run quieter andcooler and use less fuel per acre cut. Theylast several times longer than the equiva-lent horse power in an air cooled engineunder demanding situations. The initialcost penalty of $1600, or more, may besaved in overhaul and replacement.However, if the machine is to be used fortrimming the demand on the mower maynot be so heavy and a lower horse power

machine may be adequate.With a sound preventative mainte-

nance program, a hydraulic/mechanicalsystem will give greater operator con-venience and safety, will increase ma-chine productivity and versatility andoperating economy for rotary and reelmowers from 5 - 15 feet. Raising andlowering the reels and cutter decks byhydraulic power is less tiring on the op-erator and a hydraulic mower blade, setto turn at a selected speed rather thanground speed, can be energy efficient.

A hydraulic system delivers morepower in a smaller package, resulting inreduce weight of the equipment and in-crease fuel economy. Tubes and hosesare easily routed to the point of need andare located more conveniently. The unitsare smoother and quieter in operation.Because of the reduced weight there isless compaction with its adverse effecton aeration, resulting in healthier turf.

Generally a hydraulic unit will requiremore horsepower per foot of cut to drivethe blade. Bearings and hydraulic sealmaintenance can be high. Neverthelessthe limitations are outweighed by theversatility of a hydraulic unit.

DownTime(10% of the cost per acre)

Excessive down time may result due topoor equipment design, abuse of the ma-chine and the incorrect use of light duty .mowers. The result may be a high levelof overtime and transportation costs andthe bureaucracy of new equipment pur-chases. A significant part of the cost as-sociated with down time is the disruptionof the mowing schedule. The increase in

inventory to offset down time is alsoworthy of consideration.

Labour Costs(50% of the cost per acre)

This is the highest portion of the costper acre to cut grass. The cost may varyfrom minimum wage to over $16 perhour and depends on the geographic re-gion. Labour costs include the time toload and unload or otherwise transportthe mower and the fuelling and dailyservice of the mower which reduce thetime for mowing although the operatoris paid for an eight hour day. It is gener-ally considered that only 6.5 hours arespent mowing out of an eight hour day.

In addition to the base wage of theoperator are the fringe benefits such asmedical plans, pension schemes, work-men's compensation, federal and pro-vincial taxes, educational and trainingallowances, and even safety shoes andhearing protection.

Investment Costs(6% of the cost per acre)

This is an allowance for the value ofthe money which could be invested andthe mowing done by contract. Generallya mower will last for 8 to 10 years duringwhich it will operate about 6,000 hours.

GTIRESEARCHHILITESThe efficacy of many insecticides de-

pends on the placement of thematerial relative to the zone of activityof the insect. An example is the controlof the European Chafer whose larvae orgrub feeds on the crown and surfaceroots of turf species. Insecticides left onthe surface are not effective, therefore asystem for moving the material into theacti ve feeding zone is required.

The most common system is to waterthe insecticide in, but often insufficientwater is applied to move the material toan adequate depth or an irrigation systemis not available. The presence of a thatchlayer increases the difficulty of movingthe insecticide downward.

Prof. Mark Sears of the Dept. of Envi-ronmental Biology examined subsurfaceinjection systems for the placement ofinsecticides below the turfgrass thatchlayer for the control of the EuropeanChafer at two locations in 1992. Prof.Sears applied emulsifiable concentratesor flowable formulations of Diazinonand Chlorpyrifos (Dursban) to plots atrecommended and half rates. He used aconventional sprayer system applying4.5 L water/lOO m2, a Toro Hydraject

Liquid Pulse Injector at a rate of 57 Lwater! m2, and a Pattison Bros. LiquidSpoke Injector at the same rate. At alocation on the avc lawn he also ap-plied a insect parasitic nematode with thesprayer system and with the Spoke Injec-tor.

Three weeks after application the plotswere examined for live grubs within a0.33 m2 area. The results of his findingsare recorded in Table 1.

Both the commercially available insec-ticides were effective in controlling thegrubs when applied with a sprayer atCambridge where there was a high grubnumbers. Less consistent data was foundon the avc lawn where Dursban 480ECwas the better material.

The use of the two types of injectors didnot consistently improve the efficacy ofthe insecticides. The potential for theToro Hydraject system to relieve com-paction in addition to providing a systemfor applying an insecticide is an addi-tional benefit where a combined prob-lem of grubs and compaction exists.

Significant control of the Chafer wasobtained with the insect parasitic nema-tode. The nematodes applied with a con-ventional sprayer appear to be moreeffective than those injected with thespoke system. This non chemical ap-proach to control is worthy of furtherinvestigation.

Table 1. The percentage reduction in grUb numbers due to insecticide applications bythree systems in 1992.

ApplicationSystem Insecticide Rate

Cambridge* avc Lawn*

(kg a.i./ha)Taro Dursban 480EC 1.8Taro Dursban 480EC 0.9Taro Diazinon 500EC 4.5Taro Diazinon 500EC 2.25Spoke Dursban 480EC 1.8Spoke Dursban 480EC 0.9Spoke Dursban 50 WSP 2.25Spoke Dursban 50 WSP 1.13Spoke Diazinon 500EC 4.5Spoke Diazinon 500EC 2.25Spoke Nematode FullSprayer Dursban 480EC 1.8Sprayer Dursban 50 WSP 2.25Sprayer Diazinon 500EC 4.5Sprayer Nematode FullSprayer Nematode Half

(% of check)79.4 33.380.4 45.893.8 91.760.8 50.095.9 16.790.7 50.0

80.4 58.368.4 37.593.8 70.866.0 37.5

54.280.8 95.892.8 45.894.8 0.0

83.354.2

"Grub Number in Control: Cambridge = 24; avc Lawn = 12.