green world AN INDUSTRYWIDE PUBLICATION OF THE NEW JERSEY TURFGRASS ASSOCIATION Vol. 20 No. 1 Earthworms the first turfgrass cultivators My interest in earthworms was stirred in a Plant Ecolo­ gy class by Dr. J. Weaver at the University of Nebraska. Dr. Weaver, of Weaver and Clements fame, was a founder of Plant Ecology. While planning a five-day course in turf at Rutgers approximately 40 years ago, I asked a graduate student, Dave Moote (later golf course superintendent in Canada, now at Island Country Club — continued on page 3 November 1991 Thinning the turf cover Reducing Thatch and Increasing the Percentage of Young Tillers Thinning, which is sometimes called thatching, is not a new practice. Fifty or sixty years ago, turfgrowers would thin with sharpened steel rakes to re­ duce thatch accumulation. Sometimes the purpose has been to reduce pros­ trate stem growth. The trick was to leave enough live growth buds to gen­ erate new turf cover in a reasonable length of time. This has been done most often on bentgrass and bermuda- grass. Theoretically, the latter is better adapted to survival of thinning because of its (1) vigor, (2) rhizomes, and (3) tol­ erance of heat. In earlier years, some bermudagrass growers would re-dig the senescing thatchy stand to destroy thatch and to develop a new stand of vegetative growth. Often, seed has been used to help regenerate cover with bentgrass. The thinning practice surged approxi­ mately forty years ago with machines like the Verticutt (flailing vertical knives) and the Aerothatch (a power driven reel of knives that cut gooves). These machines made it possible to power flail-out significant quantities of the thatch layer. Of course, thinning raised the following concerns: (1) Will opening the cover cause loss of stand from sunburn of exposed plant parts in the green layer? (2) Will it increase weeds? — continued on page 5 Figure 1, to the left, shows September thinning with vertical mower on mixed turf of Kentucky bluegrass and bentgrasses. Figure 2, to the right, shows May thinning. Treatments were conducted from 1964-69 at the New Jersey Agricultural Experiment Station of Rutgers Uni­ versity. Species content was determined with a point quadrant and leaf identification on replicated plots. Opinions and Comments Soil Core Removal and Sinking Greens Leaving the soil from coring greens has two schools of thought — those “who leave them" and those “who take them off” with conviction. To examine this diversity of procedure, we can start with the reasons for cultivating and topdressing. Thatch control, keep­ ing the surface open and stimulating new shoots are primary benefits. For discussion on leaving soil cores, we are especially interested in the rea­ sons for topdressing as follows: truing the surface, reducing dry spot prob­ lems, thatch control and increasing the depth of root zone. All of these can be good reasons for leaving soil from cor­ ing. Additional reasons are reduced chance of diverse layers in the soil pro­ file and retaining soil-like materials. Most greens will benefit from soil cores — as they supplement prepared top­ dressing for thatch control. Paul Weiss Sr., a respected golf course superin­ tendent from Pennsylvania, said, "Soil cores are the poor club’s topdress­ ing.” Reasons for removal (1) To minimize spreading of weed seed from below the germinating layer onto the surface of greens that have been free of weeds for several years. (2) To minimize messiness that de­ tracts from putting green appeal for the golfer. (3) To permit quicker dilution of a top­ soil used in construction that is too — continued on page 3 Green World is published three times a year by the New Jersey Turfgrass Association, P.O. Box 231, New Brun­ swick, NJ 08903. Agronomic editors: Drs. Ralph Engel and James Murphy; advertising chairman, Sam Leon; pro­ duction editor and layout artist: David Crismond. Sustaining Members of NJTA A-L Services Incorporated A. Lombardi Landscaping Aabar, Inc. / The Morie Co. Alan C. Cruse, Inc. Alpine Country Club Aqua-Flo, Incorporated Aquarius Irrigation Supply Aquashade, Inc. Aquatrols Corp, of America, Inc. Arthur’s Landscape & Irrigation Co. Associated Marketing, Incorporated Barefoot Grass Lawn Service Basking Ridge Golf Course, Inc. Becker Landscaping, Inc. Brouwer Turf Equipment, Ltd. Cedar Creek Golf Course Chux Landscaping, Inc. Coger Farms & Garden Center Crincoli Landscaping Service, Inc. D & J Landscaping D. Marzano Landscaping, Inc. De Lalio Sod Farms, Inc. Debuck's Sod Farm Del Val Design Landscape Double Eagle Equipment Company Dowelanco DuBrows's Nurseries Duke's Landscape Management, Inc Duke's Lawn Service, Inc. Ehrlich Green Team Evergreen Lawn Sprinklers Excel Landscape Services, Inc. Fairview Country Club Fairway Green Inc. 1991 OFFICERS OF THE N.J.T.A. Richard Hurley, President Robert Dobson, V President Ralph Engel, Secretary Bea Devine, Exec. Secretary Joseph Bianco, Treasurer Robert Dickison, Past President EXECUTIVE BOARD Richard Caton Richard Hurley Armand LaSage Samuel Leon L.J. Makrancy, Jr. Joseph W. Manning, Jr. Peter McCormick Ed Milewski Bruce Nagy Steve Stys Farmstead Golf & Country Club Fertl-Soil Turf Supply, Inc. Fiddler's Elbow Country Club Florence Landscaping Service Forest Hill field Club Forsgate Country Club Fredette Landscaping Freehold Township Parks & Rec. G & G Landscaping G & L Lawn Service, Inc. Gajarsky Contracting Inc. Garfield Williamson, Inc. Glen Summit Nurseries, Inc. Grass Roots, Inc. Green Grass Landscape Service Green Oasis Landscaping Hoffman-LaRoche, Inc. Homestead Lawn Sprinkler Co., Inc. Honor Tree & Lawn Service Hopewell Valley Golf Club Horizon Estates Ingersoll Rand Division Irrigation Unlimited, Inc. JEP Sales, Incorporated Kinsway Regional High School Lakewood Country Club Landscaping & Lawn Solutions Lawn Doctor, Inc. Lawn Doctor Mtnside/Cranford Lawn Spray Company Lebanon Chemical Corp. Lee Rain, Inc. Leon’s Sod Farm Leonard Reinhardt, Inc. Lesco, Inc. Lipinski Landscape & Irrigation Lofts Seed Incorporated M. J. O'Brien Contr., Inc. MacAndrews & Forbes Company Meadowbrook Lawn Service, Inc. Middletown Sprinkler Company Montco Products Corp. N. E. Criaris Enterprises, Inc. Nardozza Landscaping National Lawn Services of NJ, Inc. NJ Nursery & Landscape Assh., Inc. NK Lawn & Garden Co. Northern Turf Management P. Tappen Horticultural Paige Electric Corporation Partac Peat Corporation Pennink Arrimour ,nc.v Pennsauken Country Club Peirson's Mill Co. Pine Hill Youth Association Pine Island Turf Nurseries, Inc. Rancocas Valley Regional High Sch. Earthworms — the first turfgrass cultivators — continued from page 1 in Naples, Florida), what topic he would like. We decided on the topic of earth­ worms in turf. His presentation in the 1950’s was abstracted in the Rutgers Proceedings for that year. His com­ ments that earthworms are worthy of tolerating in some types of turf for their cultivating action “ruffled some feath­ ers.” This was the era of post-World War II turf when slicers, hole-cutters and deep-tine cultivators had their greatest development. I received a very severe reprimand by two of the nation’s turfgrass agronomists, asking if I had not heard of the “aerifiers.” Of course, both the interest in earth­ worms and cultivating machines has continued. The New Jersey Turfgrass Association Greenworld published a second article on earthworms in June, 1986. This article mentioned the value of earthworms for opening the soil and reducing thatch. The 1986 article detailed various conditions that favored earthworm ac­ tion and some of the ways earthworms benefit turf. They commonly create channels of 9- or 10-inches into the soil. They will go appreciably deeper with drying of the soil or with extreme temperatures. With larger populations, 25 to 30 channels per square foot have been counted. They do give some grinding of soil particles, but most im­ portantly for turf, they pull plant parts into the opening and mix them with the soil. Their digestive tract has enzymes and microflora that help digest organic matter. As many as 200-400 earth­ worms have been counted in the profile of a square yard of soil. Earlier studies in Europe, New Zealand and Australia showed an active earthworm population can deposit an inch of soil on the sur­ face in a three- to eight-year period. The earthworm aids soil permeability, plant nutrient availability and thatch control. Their work has shown signifi­ cant increases in plant growth in crop plants and turf. When it is desired to encourage earthworms, do not overlook liming. They thrive in well-limed soils as com­ pared with acid soils. When on this subject, remember that with a few ex­ ceptions, most of the nitrogen carriers increase acidity. Thus, with higher rates of nitrogen, more lime is needed to maintain a well-limed soil. The objections to earthworms are largely from the casts that interfere with putting surfaces (this is especially — continued on page 4 NEW DISTRIBUTION CENTERS in the EAST. WEST. SOUTH & MID WEST SOIL CONDITIONER A DRYING AGENT "SUPER BED" FOR INFIELDS "SUPER GREEN " FOR TURF MORE COLORFUL. LESS DUSTY IMPROVES AERATION & DRAINAGE YET RETAINS NUTRIENTS & MOISTURE AMERICA'S PREMIUM HEAT-TREATED TOP-DRESSINGS PARTAC GOLF COURSE TOP-DRESSING THE PROFESSIONAL'S CHOICE . . SINCE 1922 USED BY OVER 60 PRO TEAMS, OVER 300 COLLEGES, PLUS TOWNS & SCHOOLS ACROSS THE U.S.A. AND CANADA. SPECIAL MIXES FOR INFIELDS, PITCHER'S MOUNDS, HOMEPLATE AREAS & RED WARNING TRACKS. Terra Flow DRAINAGE SYSTEMS PARTAC Green Sand For Divot Repair The Ultimate Solution to Unsightly Divots at Televised Golf Tournaments and other Sports Events! AVAILABLE NATIONWIDE 1-800-247-2326 IN NJ. 908-637-4191 PLUS CONSTRUCTION, CART PATH, SAND TRAP, AND DIVOT REPAIR MIXES TYPAR GEOTEXTILES & TURF COVERS YOUR ONE-STOP SOURCE FOR AMERICA'S FINEST SPORTS SURFACES & SUPPLIES! PARTAC PEAT CORPORATION, KELSEY PARK, GREAT MEADOWS/N.J. 07838 ORLANDO, (FL) RIPLEY (MA) MEMPHIS (TN) SOUTH BEND (IN) RENO (NV) Opinions and Comments Soil Core Removal — continued from page 2 high in clay and silt. Similarly, removing cores speeds dilution from a layer of im­ proper topdressing material. The latter two situations are proble­ matic. First, a cursory judgement that greens have an incorrect soil texture can be wrong. High sand greens can be hard. Tests and expertise are needed to be sure what a faulty greens soil needs. Also, there is a chance that purchased or course-prepared top­ dressing may be worse than the soil in the greens. A sometimes overlooked factor in core removal is that small dusting-type applications of topdressing with core removal may give a net loss of root zone depth. This is a serious short­ coming for those greens that need more depth of better soil. Topdressing to im­ prove the soil base is needed on many greens. Often, this is the only chance for correcting the soil by courses that find it difficult to take a green out of play for rebuilding. You will find it inter­ esting to determine the gain or loss in depth from the removal of soil cores and/or topdressing. Removing soil cores is not a clear "yes-or-no" situation. I believe strongly that leaving them is the right answer, on most occasions. If the cores are high in silt or clay, remove them. Topdress­ ing is a good antidote for thatch control, but most greens need more for control of this problem. More depth of good soil on greens is an important role for cores. For those who say removal of cores is easier, reconsider matting soil off the cores with the right weather. I did a lot of this with student help on the half-acre plus green at the Dudley Road site. «REE Earthworms — the first turfgrass cultivators — continued from page 3 true for the “oriental” earthworms), and the muddiness that can occur on the turf. Some claim they expose buried weed seed, but this seldom appears as a problem. In 1990, Drs. Potter and Powell, Ken­ tucky scientists, published an article on the action of earthworms in turf. Their work concentrated on organic res­ idue* in the soil and the action of the worm on the physical condition of Ken­ tucky bluegrass turf. Thatch pieces were placed in nylon mesh bags with * POTTER, D.A. 1991. Earthworms, Thatch and Pesticide. Green Section Record. Vol. 29:6-18. TORO- STORR TRACTOR CO. 3191 U.S. Highway 22 Somerville, N.J. 08876 201-722-9830 1385 Lakeland Ave. Bohemia, L.I., N.Y. 11716 516-589-5222 opening sizes that give varied admis­ sion to earthworms. These were placed just below the soil surface for 23 months. At the close, plots (thatch pads) exposed to earthworms, had 80% mineral soil by weight compared with 35% mineral soil where the worms were not present. With regard to pesticides, Dr. Potter wrote, “The Fungicide beno- myl (Benlate) and the insecticides dia­ zinon, carbaryl (Sevin), ethoprop (Mo- cap) and bendiocarb (Turcam) all dramatically reduced the earthworm populations. The last three materials reduced populations by an average of 76-99% across two tests. All of the treatments significantly reduced the rate of breakdown of the buried thatch. Less severe but significant earthworm Sustaining Members of NJTA Rapp Sod Farm Reed’s Sod Farm Reid Sod Farm Rich Green Lawns Rockland Corp. Rosedale & Rosehill Cemetery Assn Royal Lawns of Monmouth S & A Irrigation & Lawn Services Sacco's Landscape, Incorporated Sandoz Crop Protection Scian's Landscaping Inc. Seabright Lawn Tennis Club Seacoast Labs Sequoia Lawn Care Shearon Envir. Design I NJ Sleepy Hollow Country Club Spring Meadow Golf Course Spring-Green Lawn Care Stephen Kay Golf Course Arch. Storr Tractor Superlawns of Atlantic City Surf Landscaping Sweeney Seed Company The Bedens Brook Club The Brickman Group, Ltd. The Scott Company Town & Country Nursery Trenton Country Club Turf Grass Sod Farms, Inc. Turf Management Systems, Inc. Turf Seed Inc. Upper Montclair Country Club W. A. Cleary Chem. Corp. Wayne Board of Education Wayne Township Parks Department Wilfred MacDonald, Inc. Willow Run L/M Div., Inc. Woodbridge Center Woodbury Public Schools Woodruff/Lerco Lawns of S. Jersey WRTCO, Inc. One of the greatest obstacles to suc­ cess is man’s ability to put first things first. -Charles Roth Grow angry slowly - there is plenty of -Ralph Waldo Emerson time. God only asks for 10% of my income, what right does the government have to ask for 50% or more? mortality was caused by isofen- phos (Oftenol), tri- chlorfon (Proxol or Dylox), chlorpyri- fos (Dursban) and isazophos (Triumph). In long-term tests, Diazinon, Benlate, Sevin, Mocap and Turcam were evaluated in larger plots for a longer period of time. The 13 x 13 plots were treated once at labeled rates in May and earthworm sam­ ples were taken at 1, 3, 5, 20 and 47 weeks. The last four insecticides had severe impact — cont, page 6 Thinning the turf cover — continued from page 1 (3) Will it cause shifts in species con­ tent? The practice of thinning has grown and the development of more efficient machines has continued for 50-60 years. There are a great number of flail- type machines in use for thinning. There is a good assortment of ma­ chines that give both thinning and groove-slicing. These differ from verti­ cal mowers and flails which are not de­ signed to disturb the soil. Theory, Use and Results From Thinning (Dethatching) The theoretical benefits of thinning go beyond thatch reduction. Thinning makes room for new tillers, which is possibly as important as reducing the country club greenskeeper Lebanon Pro Professional Turf Products Lebanon TOTAL TURF CARE P. O. Box 189, Dayton, NJ 08810 P. O. Box 180, Lebanon. PA 17042 A division of Lebanon Chemical Corporation The passion for equality produces uniformity which produces medio­ crity. -Alexis Detocqueville thatch layer. Thinning reduces loose stolons and fluffy senescent turf. Most overlooked is its use for discouraging one species over another. Figures 1 and 2 on the front page give some of my research, which showed thinning turf can reduce bentgrass and increase Kentucky bluegrass. Annual thinning in September-October over five years en­ abled Kentucky bluegrass to become highly dominant over bentgrass. In contrast, May thinning suppressed Kentucky bluegrass and enabled bent­ grass to become a major component of the turf. This test was preceded by several de­ foliation observations on thinning of turf showing the following results of interest and potential for research. (1) Thinning of a New Jersey lawn of Merion Kentucky bluegrass that was losing vigor (apparently from thatch and related problems) was thinned severely (50% removal of green aspect) in Octo­ ber with the thought this would not harm the lawn and still permit recovery by spring. The result was serious winter- kill. (2) An observation on a Kentucky blue­ grass lawn that received April thinning at the Wooster Ohio Experiment Sta­ tion gave better regrowth in spring and summer as compared with the untreated checks. (3) May thinning gave increases in crabgrass on some of my tests. •REE Rockland Professional Products For Lawns, Gardens And Trees Join the growing number of businesses that are selling and using Rockland professional products on residential properties, corporate sites, municipal areas, athletic fields — anywhere superior results are needed. ■ Fertilizers ■ Fertilizer/Pre-emergent Crabgrass Control ■ Fertilizer/Herbicide Combinations ■ Crabgrass Preventers ■ Herbicides ■ Fungicides ■ Insecticides ■ Specialty Products ■ Granulars & Liquids ■ Custom Formulations and Blending Available Request a complete Professional catalog by phone or letter. Rockland P.O. Box 809, West Caldwell, NJ 07007 From NJ 201-575-1322 Outside NJ 800-543-1311 Jacobsen Turfcat II GW 224 Wilfred Mac Donald, Inc 340 Main Avenue Clifton, NJ 07014 201-471-0244 •Jacobsen •Olathe • National • Gravely •Giant Vac •Broyhill •Cushman •Howard • Smithco • FMC •Terra-Care Earthworms — the first turfgrass cultivators — continued from page 4 that reduced populations from 40-77% and reductions were still evident after 20 weeks. Thatch decomposition rates were significantly reduced, but earth­ worm populations recovered to near normal in 11 months. Summary comments Dr. Potter’s work shows the earth­ worm accomplished much of its effect by mixing soil with thatch and digesting plant residue. This method of biological control is nature's way. What reason do we have for not using it, except when casts are a problem? Thatch problems are often inade­ quately controlled with moderate culti­ vation and topdressing. Let the earth­ worms help with thatch control and opening the soil. I am not proposing elimination of turf cultivation. This can be helpful in seasons when earthworms are inactive. Use both techniques as needed and feasible. Earthworms have the nice advantage of a neat channel to a greater depth than most machines. Their channels have been noted to stay open for con­ Patrons Listing Samuel Leon LEON'S SOD FARMS Instant Lawn-Cultivated Grass Sod RD#1 Box 169 Frenchtown, NJ (201) 996-2255 08825 Marty Futyma FERTL-SOIL TURF SUPPLY, INC. Greens, Top-dressing, Turf Supply 514 Martin Road Scotch Plains, NJ 07076 (201) 322-6132 Consider the advantages of sod TURF TYPE TALL FESCUE Trap banks and edges, green and tee banks and areas along cart paths need special attention. Or even those traffic areas around the club and halfway houses. Consider Rebel sod: • Holds up better than Kentucky bluegrass • Requires less irrigation compared to Kentucky bluegrass • Requires less fertilizer than Kentucky bluegrass • Heat tolerant • Excellent dark green color • Greater disease resistance than most other turfgrasses In tough areas or wherever you want good-looking turf and less maintenance. Use Rebel sod. Lofts Seed Inc. World’s largest marketer of turfgrass seed Bound Brook, NJ 08805 (201) 356-8700 • (800) 526-3890 LOFTS Available through: S. Novasack Bros. Turf Farm South Seaville, NJ (609) 263-2400 Tuckahoe Turf Farms Tuckahoe, NJ (609) 628-2415 Bohm’s Sod Farm Woodbine, NJ (609) 861-2785 Pine Island Turf Pine Island, NY (914) 258-4545 siderable time in loam or clay soils. When the older worms die, the larger populations contribute significant amounts of slow release nitrogen and other nutrients. There are different species and strains of earthworm that occur natural­ ly. Earthworms are worthy of our liming Bob Scott DOWELANCO 560 Ashwood Road Springfield, NJ 07081 (201) 376-7290 Ken Stattel BROOKREST SOD FARM P.O.Box 122 Marlboro, NJ 07746-0122 Drew Madzin ROYAL LAWNS P.O. Box 236 Farmingdale, NJ 07727 (201) 780-4950 very acid soils to increase their num­ bers as desired. Next, we hope manu­ facturers will tell us when their pesti­ cides affect earthworms. If a pesticide that is severe on earthworms must be used, hopefully it will not be needed two or three consecutive years. •REE Rick Apgar, Joe Stahl METRO MILORGANITE, INC. 365 Adams St. Bedford Hills, NY 10507 (914) 666-3171 W.A. CLEARY CHEMICAL CORP. 1049 Somerset Street Somerset, NJ 08873 (201) 247-8000 [Turf Chem & Fert] Call: Barbara Cleary or Russ Ward