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 Australian and 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 stadiumsaround 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, 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. 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 Congress in 1862, settlers in the Great Plains used sod bricks to build entire sod houses. This was effective because 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. Different types of grass used for sod installation
Cultivation
Sod is grown on specialist farms. For 2009, the United States Department of Agriculture reported 1,412 farms had of sod in production. It is usually grown locally 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 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, so time to export is shortened.
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. Sod reduces erosion by stabilizing the soil. Many prized cultivars only reproduce vegetatively, not sexually. 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.
Tall fescue is a cool-weather group of grasses originating in Europe, commonly used as sod. It exhibits moderate tolerance to both drought and cold, and as such is especially popular in inland temperate environments referred to in the turf and landscaping industries as the "transition zone", where summers are too hot for most cool-weather grasses, yet winters are too cold for most warm-weather grasses. Fescue is well-adapted to clay soils, moderately shade-tolerant, and somewhat resistant to disease, yet still vulnerable to brown patch and Fusarium patch. It grows most actively in spring and fall, and requires frequent watering during summer. Due to its bunch-type growth habit, it will not spread undesirably or invade adjacent areas once sodded, yet neither will it fill in voids, and periodic maintenance may be required to sustain a homogeneous surface. It has poor wear tolerance compared to Bermuda grass, making it less popular for applications such as athletic fields.
Fine fescues
Fine fescues are less popular as sod than the tall fescues. As their names suggest, they exhibit much thinner leaf blades, and tolerate lower mowing heights than the tall fescues. They may be somewhat more resistant to common diseases. Otherwise, their characteristics are similar. Fine fescues are generally used in mixtures with other grasses.
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. The aggressive and resilient nature of Bermuda grass makes it not only an excellent turfgrass but also 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, it has been the subject of numerous studies. Celebration Bermudagrass: Discovery Bermudagrass:
Bluegrass
Bella Bluegrass:
St. Augustine grass
is warm-season, perennial grass that is a widely used. A native grass of tropical origin that extends from marshes, lagoon fringes, and sandy beach ridges. St. Augustine lawns are a popular coarse, wide–bladed coarse lawn planted throughout many areas of the Southeastern United States 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, as seeds are not usually available due to production difficulties. Captiva St. Augustine:
Centipedegrass
Covington: Santee:
Natural turf communities
Low growing vegetation is referred to as "turf communities" in areas where such growth is not common, as in moss-turf communities of sub Antarctica, some epifauna in the sea, coral reefs and, in New Zealand, as species-rich communities of plants under tall, on coastal headlands, dune hollows, rivers and lakes, where most of the natural cover was forest. A form of turf community is a herbfield.
