Best Management Practices for Maryland Golf Courses

Cultivation

Cultivation involves disturbing the soil or thatch using various methods to achieve important agronomic goals: compaction relief, thatch/organic matter reduction, and improved water and air exchange. However, cultivation can require significant time for recovery, thus disrupting play, and should be used judiciously. Cultivation frequency should be based on traffic intensity, level of soil compaction, and the amount of accumulation of excessive thatch and organic matter, which reduces root growth, encourages disease, and creates undesirable playing conditions. Cultivation techniques include core aeration, deep drilling, verticutting, grooming, solid tining, and spiking/slicing. Table 7 lists these cultivation approaches and presents a relative ranking of the agronomic benefits of each (republished with permission from Environmental Best Management Practices for Virginia’s Golf Courses , Table 7-4, p. 94):

Table 7. Turfgrass Cultivation Methods and Rankings of Agronomic Benefits

Water/air movement

Method

Compaction Relief

Thatch control

Disruption of play

High

Good

High High

Medium to high

Core aeration Deep drilling Verticutting

Medium

Low Best

High

Low None Low None

Medium Very low

Low to high

Very low

None

Grooming Solid tining

None

High Low

Medium-low

Very low

None

Spiking/slicing

Core aeration is effective at managing soil compaction and aiding in improvement of soil drainage by removing small cores or plugs from the soil profile. Cores are usually 0.25 to 0.75 inches in diameter. Using bigger tines and therefore removing larger cores will disrupt play for longer. Deep-drill aeration creates deep holes in the soil profile through use of drill bits. Soil is brought to the surface and distributed into the canopy. Holes can be backfilled with new root-zone materials if a drill-and-fill machine is used. These machines allow replacement of heavier soils with sand or other materials in an effort to improve water infiltration into the soil profile. Vertical mowing (verticutting) can be incorporated into a cultural management program to achieve a number of goals. The grain of a putting green can be reduced by setting a verticutter to a depth that just nicks the surface of the turf. Deeper penetration of knives will stimulate new growth by cutting through stolons and rhizomes while removing accumulated thatch. Deep verticutting (0.5 to 1 inch depth) removes a greater amount of thatch than core aeration and can be considered for aggressive thatch removal as it can remove up to 15% of the thatch at one time. However, it is aggressive and should only be done during less stressful times (e.g., cooler temperatures) and on well-rooted turf. Unlike deep verticutting, shallow verticutting (0.5 inches or less) does not remove thatch. Instead, it severs stolons to promote new growth while also standing up blades for removal of old growth and minor canopy thinning. Shallow verticutting can be practiced regularly during the growing season except in times of drought or excessive heat.

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