The benefits of modern fairway grasses are well known: Maintenance is simplified, and play characteristics are enhanced. However, converting Poa/bluegrass fairways to new varieties of bentgrass isn't so simple.

Course contractor Golf Creations recently completed a project at Rockford (Ill.) Country Club where 30 bunkers required reshaping, new drainage and new sand. The club also authorized the conversion of 30 acres of fairways to bentgrass. In the Chicago area, converting old Poa/bluegrass fairways is a construction process that is relatively new and untested.

A serious concern for long-term maintenance care was seeding into the thatch layer. To get around potential problems at the 100-year-old club, we treated its fairway conversion like a new course construction project.

A bunker renovation going on simultaneously provided the opportunity to recontour the playing areas surrounding the newly shaped fairway and greenside bunkers. In late July, when the bunker renovation work was about to begin, glyphosate (Roundup) was applied to these 30 acres of fairway. The product was on the ground for a week before any construction began.

After a week's respite, a Rex tiller was used to a depth of approximately 5 inches. This tiller is used in road construction to break up asphalt before paving. It pulverizes the soil to a perfect cultivation depth, provided there is not an extensive thatch layer. More thatch means more debris, which can hamper seed-to-soil contact. Blowers can remove excess debris, but you don't want the soil perfectly clean because the right amount of thatch debris left in the soil provides good erosion control.

The seedbed at Rockford was then prepared using the following implements:

	A Gill pulverizer attached to a small tractor for smoothing out the surface and spreading the debris evenly throughout the fairways
	A box blade for providing the desired fairway contour
	A cultipacker for "packing" the soil together with the thatch debris to make a firm, even surface

A soil fumigant (Basamid) was then applied at a rate of 275 pounds per acre with a drop spreader attached to a utility vehicle.

The watering schedule was 10 minutes per head, every hour for the first three hours. After this initial period, the fairways were watered for 15 minutes, three times a day for four days. The fairways were then given a couple of days to dry before seeding began.

Given this sort of preparation, the seeding process becomes a simple matter. A tractor with the Gill pulverizer prepares the seeded area, disturbing only the top 1-2 inches of soil. In sandy soils the sterilization from the soil fumigant can reach a depth of 6-8 inches, but in heavy soils it may be 3-4 inches. Therefore, it is necessary to prepare only the top 1-2 inches of sterilized soil as a seedbed.

A normal starter fertilizer was then applied, as well as a bentgrass 50-50 mixture of L-93 and Providence with a seeding rate of 2 pounds per 1,000 square feet. Normal grow-in procedures were then followed.

This fairway conversion was completed quickly and successfully. Three to six months after seeding, the Poa annua stand was less than 2-4 percent on fairways that had been 85-90 percent Poa. Turf management techniques can now keep the Poa to a minimum for many years. And the newly refurbished bunkers look and drain great.

David Schingel is the staff agronomist with the Marengo, Ill.-based construction firm, Golf Creations. He would like to dedicate this article in memory of Walter Mattison, CGCS, a 19-year GCSAA member who passed away in December 2000.

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