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Presentation of Pioneer's "PR39F58" maize at Werktuigendagen, Belgium 2009 Presentation of Pioneer's corn seeds near Lahr in Germany. The headquarters of Dupont Pioneer are located in Johnston, Iowa, with additional offices around the world. Pioneer produces, markets and sells hybrid seed corn in nearly 70 countries worldwide.
Cropping periods were usually one year, but were extended to two or three years on very favourable soils. Fallow periods were between 20 and 40 years (Linnard 1970, 195). In Finland in 1949, Steensberg (1993, 111) observed the clearing and burning of a 60,000 square metres (15 acres) swidden 440 km north of Helsinki.
Crop rotations also affect the timing and length of when a field is subject to fallow. [37] This is very important because depending on a particular region's climate, a field could be the most vulnerable to erosion when it is under fallow. Efficient fallow management is an essential part of reducing erosion in a crop rotation system.
Fallow syndrome is when a crop has insufficient nutrient uptake due to the lack of arbuscular mycorhizae (AM fungi) in the soil following a fallow period. Crops such as corn that are prone to fallow syndrome should not follow a period of fallow, but instead should follow a cover crop which is a host for AM fungi, such as oats or other small grain crops.
The three-field system is a regime of crop rotation in which a field is planted with one set of crops one year, a different set in the second year, and left fallow in the third year. A set of crops is rotated from one field to another. The technique was first used in China in the Eastern Zhou period, [1] and was adopted in Europe in the ...
Pioneer species tend to be fast-growing, shade-intolerant, and tend to reproduce large numbers of offspring quickly. The seeds of pioneer species can sometimes remain viable for years or decades in the soil seed bank and often are triggered to sprout by disturbance. [19] Mycorrhizal fungi have a powerful influence on the growth of pioneer ...
Fields which are fallow may be tilled or sprayed to control weeds and conserve moisture in the soil. The 1997 Census of Agriculture reported that 20,900,000 acres (85,000 km 2 ), almost 5% of the 431 million acres (1,740,000 km 2 ) of all cropland, was fallow that year.
As a result, DeKalb was the leader in U.S. hybrid seed corn sales from the mid-1930s until the mid-1970s (Crabb 1948. Roberts 1999). [2] In 1982 DeKalb formed a joint venture with Pfizer, called DeKalb-Pfizer Genetics, and in 1985 the name was changed to DeKalb Corporation. The seed business was spun off as DeKalb Genetics Corporation in 1988. [4]