Sod

Rolled sod

Golf course turf

Harvesting sod

A typical roller mower operating on a sod grass farm.

Sod or turf is grass and the part of the soil beneath it held together by its roots or another piece of thin material.

In British English, such material is more usually known as turf, and the word "sod" is limited mainly to agricultural senses.

Uses

Sod is typically used for lawns, golf courses, and sports stadiums around the world. In residential construction, it is sold to landscapers, home builders or home owners who use it to establish a lawn quickly and avoid soil erosion. Sod can be used to repair a small area of lawn,^[1] golf course, or athletic field that has died. Sod is also effective in increasing cooling, improving air and water quality, and assisting in flood prevention by draining water.^[2]

Scandinavia has a long history of employing sod roofing and a traditional house type is the Icelandic turf house.

Following the passage of the Homestead Act by the US Congress in 1862, settlers in the Great Plains used sod bricks to build entire sod houses.^[3] While it might be hard for some to imagine sod as a suitable primary building material, the prairie sod of the Great Plains was so dense and difficult to cut it earned the nickname Nebraska marble. Blacksmith John Deere made his fortune when he became the first to make a plow that could reliably cut the prairie sod.^[4]

Cultivation

Sod is grown on specialist farms. For 2009, the United States Department of Agriculture reported 1,412 farms had 368,188 acres (149,000.4 ha) of sod in production.^[5]

It is usually grown locally (within 100 miles of the target market)^[6] to minimize both the cost of transport and also the risk of damage to the product. The farms that produce this grass may have many varieties of grass grown in one location to best suit the consumer's use and preference of appearance.

It is usually harvested 10 to 18 months after planting, depending on the growing climate. On the farm, it undergoes fertilization, frequent mowing, watering, and subsequent vacuuming to remove the clippings. It is harvested using specialized equipment, precision cut to standardized sizes. Sod is typically harvested in small square or rectangular slabs, or large 4-foot-wide (1.2 m) rolls.

Mississippi State University has developed a hydroponic method of cultivating sod. For the very few sod farms that export turf internationally, this soilless sod may travel both lighter and better than traditional sod. Additionally, since the sod is not grown in soil, it does not need to be washed clean of soil down to the bare roots (or sprigs), so time to export is shortened.^[7]

Immediacy

In many applications, such as erosion control and athletic fields, immediacy is a key factor. Seed may be blown about by the wind, eaten by birds, or fail because of drought. It takes some weeks to form a visually appealing lawn and further time before it is robust enough for use. Turf largely avoids these problems, and with proper care, newly laid sod is usually fully functional within 30 days of installation and its root system is comparable to that of a seeding lawn two or three years older.^[8] Sod reduces erosion by stabilizing the soil.^[9]

Many prized cultivars (such as Bella Bluegrass) only reproduce vegetatively,^[10] not sexually (via seed). Sod cultivation is the only means of producing additional plants. To grow these varieties for sale, turf farms use a technique called sprigging, where recently harvested sod mats are cut into slender rows and replanted in the field.

Cultivars used

Bermuda Grass

Bermuda grass is quite commonly used for golf courses and sports fields across the southern portions of the United States. It tolerates a range of climates in the U.S., from hot and humid lagoons, inlets, and bays of the Gulf Coast, to the arid expanses of terrain like plains and deserts in the south and lower Midwest. "Established bermuda grass is a network of shoots, rhizomes, stolons, and crown tissue together that usually form a dense plant canopy. This dense plant canopy can be used to propagate clonal varieties by sod, sprigs, or plugs.^[11] The aggressive and resilient nature of Bermuda grass makes it not only an excellent turfgrass but also, unfortunately, a challenging and invasive weed in land cultivated for other purposes. Its one noted weakness is its relatively low tolerance of shade. Given the economic importance of Bermuda grass (as a sod product, agricultural forage, and, at times, as an invasive weed), it has been the subject of numerous studies.

Celebration Bermuda Grass

"‘Celebration’ is a dark–green, fine–textured, aggressive, traffic–tolerant cultivar with high recuperative potential and drought tolerance."^[12] The cultivar is a breed of Cynodon dactylon from Australia developed by turfgrass breeder Rod Riley.^[13] The grass has a distinctive deep blue–green color which makes it popular on golf courses and for private home lawns throughout the southern United States. As a leading cultivar, the research on Celebration is extensive. Celebration was rated for the best shade tolerance by the United States Golf Association.^[14] A researcher at the University of Florida report noted this cultivar's, "good wear tolerance, quality, and color ratings" in the Central Florida environment.^[15] Celebration was the overall best–performing turfgrass in a 2–year drought resistance study commissioned by the San Antonio Water System and performed by Texas A & M extension service.^[16] The cultivar was also the top–rated Bermuda grass for drought resistance in a test conducted in South Carolina.^[17] Along with many golf courses across the southern United States, the Tampa Bay Buccaneers elected to install Celebration Bermuda grass in their stadium.^[18]

Discovery Bermuda grass

Discovery is a Bermuda grass that has an exceptional dark blue-green color. It also has extremely slow vertical growth which means that it only needs to be mowed once a month. Discovery has the drought resistance of a Bermuda grass but does not need to be maintained as much as other varieties. It was developed in Europe. It was made available in the United States in 2011 by Sod Solutions which owns the right to market it in the United States.^[19] It grows well in all of the southern United States.

Bluegrass

Bella Bluegrass

Bella Bluegrass was developed by the University of Nebraska as a drought–resistant grass that would help states conserve water. It was immediately embraced by schools and homeowners in the state of Utah who are voluntarily trying to conserve water.^[20] Bella is the world’s first dwarf, vegetative Bluegrass. It is sold only as sod, not as seed. Bella is a quick grower laterally but has very minimal vertical growth. Because it only grows to about 4" in height, it requires less mowing. It grows in sand, clay, muck, and peat soils, and it is currently being adopted across the northern United States.^[21]

St. Augustine grass

St. Augustine Grass (Stenotaphrum secundatum) (also known as Charleston grass in South Carolina and Buffalo Turf in Australia) is warm–season, perennial grass that is a widely used. A native grass of tropical origin that extends from marshes (salt & freshwater), lagoon fringes, and sandy beach ridges.

Saint Augustine lawns are a popular coarse, wide–bladed coarse lawn planted throughout many areas of the Southeastern U.S. This grass is found in Mexico, Australia, and in tropical parts of Africa. It is a warm–season grass that does not handle cold weather very well. The majority of this grass is planted in vegetative forms (such as plugs and sod), as seeds are not usually available commercially each season due to production difficulties.

Captiva St. Augustine

Developed by the University of Florida in 2007,^[22] Captiva is a chinch bug resistant St. Augustine cultivar. It has a lush, dark–green color with a dense canopy and a massive root system. Because it has a slow leaf–blade growth and lateral spread, the requirement for mowing is reduced. Captiva has a good–excellent shade tolerance and has excellent pest resistance which means there is less need to use pesticides.

Centipedegrass

Covington

Centipedegrass was introduced into the United States from southeastern Asia in 1916. It does well in the climate and soils of central and northern Florida and is the most common home lawn grass in the Florida Panhandle.^[23] Covington is a proprietary cultivar of centipede grass from Sod Solutions, Inc. that grows in the southeast United States, from the west half of Texas to all of Louisiana, most of Mississippi, Alabama, Georgia, South Carolina, North Carolina, and Virginia. It is the only uniformly green centipede grass on the market. It is a low–maintenance grass, which retains its color in the fall and greens quickly in the spring. This variety is currently being evaluated by the University of Florida.^[23]

Santee

Santee grass is another new proprietary selection from Sod Solutions, Inc., which is also being evaluated by the University of Florida for adaptation to Florida use.^[23]

See also

• Cob (building)
• Divot
• Groundbreaking
• Peat
• Sod house
• Sod Solutions

References

External links

Wikimedia Commons has media related to Rolled sod.

• Average cost of sod installation
• Australian turf farms and commercially available turfgrasses