1.1 Definition
Plasticulture is defined as the practice of using plastic materials in agricultural applications, and according to the American Society for Plasticulture, it means “use of plastics in agriculture.” Plastic materials are broadly referred to as “ag plastics.” Plastics are applied in agriculture in different ways, including plastic mulch films, micro-irrigation (sprinkler, drip irrigation, rain gun, foggers, etc.), crop covers, greenhouses and low tunnels, silage bags, hay bale wraps, plastic trays, and pots used in the production of transplant and bedding plants (Lamont and Orzolek, 2004). Plastic materials gave way to different types of polyethylene films, which have revolutionized the protection of crops (Emmert, 1957; Agrawal, and Agrawal, 2005; Singh and Asrey, 2007). The history of plastic cultivation dates back to 1948, when Professor Emmert from the University of Kentucky first used polyethylene as a greenhouse film to replace glass (Anderson and Emmert, 1994; Jensen, 2004). In the United States, Emmert is known as the father of agricultural plastic development. With his contributions to greenhouses, mulches, and row covers, he described the principles of plastic technology (Emmert, 1957).
Although plasticulture includes micro-irrigation (drip and sprinkler), soil fumigation film, mulching, water storage, silage bags, and nursery pots are most frequently used, denoting the use of all kinds of plastics. Such variety ranges from plastic mulch film, row coverings, and high and low tunnels (polytunnels) to plastic greenhouses. Because of its affordability, flexibility, and easy manufacturing, polyethylene (PE) is used by a majority of growers. Low-density polyethylene (LDPE) and linear low-density (LLDPE) forms have different thicknesses. It can be modified by adding some elements of plastic that give properties beneficial to plant growth, such as reduced water loss, UV stabilization to cool soil and prevent insects, elimination of photosynthetically active radiation to prevent weed growth, and antidrip/antifog.
1.2 Plasticulture Development
Baekel, who coined the term “plastic,” invented the world’s first fully synthetic plastic (Bakelite) in New York in 1907. Many chemists have contributed to the materials science of plastics including Nobel laureate Hermann Staudinger, who is called “the father of polymer chemistry,” and Herman Mark, who is known as “the father of polymer physics.”
The first use of plastic film in agriculture was an effort to make a cheaper version of a glasshouse. Professor E.M. Emmert built the first plastic greenhouse in 1948, a wooden structure covered with cellulose acetate film and further used a more effective polyethylene film. After the introduction of plastic film in agriculture, by the early 1950s, larger-scale mulching was used in vegetables. By 1999, almost 30 million acres worldwide were covered by plastic mulch, but only a small percentage of this acreage (185,000 acres) was in the United States, and the majority of the plastic growth was occurring in economically poor areas of the world and unproductive desert regions, such as the Thar Desert.
In the agricultural sector, plastic farming is a technology that entails the use of plastics. In the late 1900s, polyethylene was available, and tar-coated paper mulches began to be used. When Warp (1971) developed the first glass replacement for widespread agricultural use, the science of plastic cultivation began. In 1938, British scientists first produced polyethylene as a film sheet. The earliest method of modifying the microclimate of crops using organic and inorganic materials was mulching (Jaworski et al., 1974).
The greenhouse technology around the world was used in two areas, with 80% throughout the Far East (Japan, Korea, China) and 15% in the Mediterranean basin. The area of greenhouse cover is increasing at a fast rate; during the last decade, it was estimated to grow every year by 20%. In the Middle East and Africa, the use of plastic greenhouses increased by 15–20% per year. In Europe, there was a weak growth area, i.e., covering greenhouses. In China, its growth is about 30% per year and, further, China translating into a volume of plastic film reaching 1,000,000 tons/year. In 2006, 80% of the area covered by plastic mulch was found in China with a growth rate of 25% per year. Plastic film is designed and developed to increase the yield of agricultural produce, shorten growth time, and increase produce size. Developments in plastic film encompass durability, optical (ultraviolet, visible, near-infrared, and middle infrared) properties, and the antidrip or antifog effect.
In the 1980s, plasticulture involved more than 2 million tons of plastic consumption per year in the world. A great number of polymers were used, from the expanded polystyrene of seedling trays to the polypropylene strings for plant knitting. The plastics in agriculture in the United States (polyethylene (PE) or polypropylene (PP) resin) were first used in greenhouses that produced vegetables for commercial sale. Emmert evaluated in 1960 plastic film that covered his greenhouse at the University of Kentucky. Interest in this new technology led to the formation of the National Agricultural Plastics Association (NA...
