2 Crop RotationCrop Rotation: Growing plants with different types of crops in succession. Types of Crops: Root, Leaves, Fruit, Flowers, Legumes Example: The first year you plant a crop harvested for its root. The following year you plant a crop harvested for its leaves.
3 Why Rotate CropsMonoculture: Growing one type of crop on the same field year after yearProblems that were encountered when the same type of plant was grown in the field year after year.Some of the nutrients will be depleted more than others based on the needs of that plantThe soil may become contaminated by large amounts of pests that attack that particular crops
4 Choosing Crops Crop Choice is based on… Environment Soil Climate PrecipitationFinancialMarket values (sale crops)Economic gains (crops for livestock)
5 Crop Rotations-Crop Rotation may include 2 – 6 different crops with each crops having a particular benefit either financial or environmental (benefit to the field) - Crops may be rotated every year or at different times in the growing season - Many crop rotations will include a legume. Remember legumes have a symbiotic relationship with bacteria that fix nitrogen = Increased nitrogen in the soil for the next crop Examples of Crop Rotation Rotate Soybeans (legume) followed by corn
6 How Crop Rotation Works Four Field Rotation: Started in the 16th century Four fields are planted beside each otherCropYear 1Year 2Field ACornCarrotsField BSoybeansField CLettuceField D
7 Crop Rotation With Animals Crop rotation may be mixed with grazing. First cows are allowed to graze in the field. Cows release manure which adds nutrients to the soil Second year (After the manure has had a chance to decompose) plants are grown on the cattle fertilized field
8 Benefits of Crop Rotation 1) Each crop depends on a specific amounts of each nutrient. Some plants will use up more of one nutrient than another. -By rotating crops you are not constantly depleting the same nutrient 2) The number of pests that attack each crop is reduced. 3) Farmers can grow more than one successful crop per year = Increased crop yields (10-25%)
9 Risk of Crop RotationMay reduce economic gain if farmer has to alternate between a high value crop and a low value cropMay require different machines (one to harvest soy and one to harvest corn)Overall the benefits out way the risks