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Ag 101 |  |
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PlantingOperations and TimingMost crops in the U.S. are planted in the spring. The exception is winter wheat, which is planted across the U.S. but concentrated in the central and southern Great Plains and the Pacific Northwest. Winter wheat is planted in the fall, goes into dormancy during the winter, and is harvested for grain the following spring. The table below shows the "usual planting dates" for six major crops. Planting dates vary by region, following the weather. For simplification, the usual range of planting dates for the top-producing states are shown; if planting dates vary widely, more than one is given. The actual planting dates may begin earlier and extend later, but these are considered the most common. Source: USDA
NASS Agricultural Handbook 628 "Usual Planting and Harvesting Dates
for U.S. Field Crops"
Equipment UsedDrills -are implements used to plant crops in closely spaced rows (typically four to ten inches); drills are commonly used for cereal crops such as wheat and can be used to plant soybeans. Grain drills are typically equipped with disks to open a small trench in the soil, a metering system to deliver a measured, controlled amount of seed to drop tubes which guide the seed to the seed trench. There must be some means (wheels or drag chains) of gently closing the seed trench with soil to cover the seeds.
Potential Environmental ConcernsOne current controversy related to planting is the choice of seeds. More and more of the seeds planted in the U.S. are genetically modified (GMOs) to make crop production more efficient, to better withstand environmental stresses such as drought, flood, frost, or extreme temperatures, to protect crops against pests such as weeds, insects, or diseases, and to be resistant to herbicides. In 1999, 25% of corn and 54% of soybeans planted in the U.S. were genetically modified. Environmental concerns related to GMOs include increased pest resistance, development of weed tolerance, and decreased genetic diversity. For example, insects exposed to a genetically engineered crop with the Bt gene (Bt is a natural toxin taken from the Bacillus thuringiensis bacteria, which is toxic to a number of insects) may become more resistant to pesticides. This is a serious concern for organic farmers who use Bt on their crops as an alternative to chemical insecticides. Another environmental concern is that, over time, some weed species could develop a tolerance to herbicides that are applied repeatedly to a crop tolerant to that herbicide. A transgenic crop might cross with another crop or weed, resulting in an undesirable crop or weed species. Others are concerned that reliance on a few genetically modified crops may reduce biological diversity. Also, a lack of genetic diversity in the food supply could increase the risk of catastrophic crop failure and threaten our food security. Back to TopBest Management PracticesTo reduce the risk of insect resistance to Bt, a certain percentage of crop acreage on every farm is normally devoted to non-genetically modified variety.
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