Athletic Fields

Cultivation / Aerationathletic_field_top_dressing

Cultivation generally includes aeration, vertical mowing and topdressing. The traffic on fields produces a compacted surface layer in the top 2 to 3 inches of soil. This results in reduced pore space, reduced internal air and water movement and gradual thinning of the turf. The centers of football fields, around sideline bench areas, soccer goal mouths and baseball diamond infields are good examples of areas prone to soil compaction. Even sandy soils are prone to compaction in these areas, especially when the field is used under wet conditions. Aeration using hollow tines (coring) or open spoons are the most common means of relieving soil compaction, encouraging deep rooting and improving turf quality. Aeration is also one of the most important and most neglected practices. Coring commonly uses a machine that removes a soil core 3 /4 of an inch to 1 inch in diameter to a depth of 3 to 4 inches. A core of soil should be removed and deposited on the soil surface. There are many other acceptable aeration techniques and pieces of equipment. Frequency of aeration generally depends on soil texture and frequency of field use. Fine texture soils, fields with heavy use and fields used when wet need more frequent aeration. As a general rule, the spacing between aeration holes should be 2 to 3 inches. This often means three passes in different directions with most aerators is necessary. Aerate fields a minimum of two times per year. The first should be done in the spring just before fertilization and the second in mid summer. Each aeration should involve a minimum of three passes over the playing field. If field use is heavy or the soil is compacted, aerate monthly during the growing season. After the soil cores have dried, they can be crumbled and spread over the turf by using a flexible steel drag mat or some other means. Slicing with solid blades 1 /4 to ½ inch wide cultivates the soil with minimum surface disruption. Units with offset times can be quite effective in relieving soil compaction. Aerate when soil moisture is at field capacity. This generally translate to 8 to 24 hours after rainfall or irrigation or when a spoon-type aerator would remove soil cores to the surface. If moisture were higher or lower, cores would not easily move to the surface. However, some equipment, particularly solid tines or blades, are most effective when soil moisture is drier than field capacity. Aerate when the turf is actively growing and not under stress.

Topdressing

Topdressing is the addition of a thin layer of soil on the turf surface. Parts of the field that are used continuously tend to become depressed from the heavy use. Topdressing with a 1 /8 -inch layer (10.4 cu. ft. or 0.4 cu. yds. per 1,000 sq. ft.) can level and smooth these areas. In addition to smoothing the surface, topdressing also reduces thatch. Topdressing after fertilization and during periods of active growth is best. Light, frequent topdressings to build up lower areas are preferred over less frequent, heavier topdressings. The topdressing soil should be of similar texture to the soil on site and can be dragged into the turf with a flexible mat.