APES 5.15 Sustainable Agriculture

Enduring Understanding:

  • Humans can mitigate their impact on land and water resources through sustainable use. 

Learning Objective:

  • Describe sustainable agricultural and food production practices.

Essential Knowledge:

  • The goal of soil conservation is to prevent soil erosion.  Different methods of soil conservation include contour plowing, windbreaks, perennial crops, terracing, no-till agriculture, and strip cropping.
  • Strategies to improve soil fertility include crop rotation and the addition of green manure and limestone.
  • Rotational grazing is the regular rotation of livestock between different pastures in order to avoid overgrazing in a particular area.

Soil Conservation

  • The preservation of soil is essential to maintaining sustainable food production practices
  • If we destroy our soil, we destroy our way of making food

Contour Plowing

  • Preserves naturals topography of the land and leaves soil intact
  • The land is the way it is for a reason   * Listening to and preserving it is the best way to extend it’s fertility and health

Windbreaks

  • Reduces wind erosion that may blow soil away
  • Physical barriers that block wind   * Can be built or be natural, like trees

Strip Cropping

  • Harvesting one crop at a different time will leave one crop present to hold the soil in place   * Remember that roots are integral to keeping soil down

Terracing

  • Decreases the velocity of water doing downhill   * This reduces soil erosion
  • Water running down a steep hill normally goes very fast and will pick up a lot of soil, but this slows it down while also watering the crops

No Till Agriculture

  • The land is not tilled or plowed before and after planting   * When tilling/plowing, the land is ripped up and aerated   * This, however, destroys root systems and exposes loose top soil
  • By not plowing, the soil is left intact and packed in, meaning it can resist erosion

Perennial Crops

  • Perennial crops are crops that return year after year, so they will always hold the soil together even when dormant
  • They only need to be replanted when the entire plant dies, which is usually not for a very long time, so the soil is never left exposed

Soil Fertility

  • Preserving soil fertility is another critical effort we must make in our agriculture

Crop Rotation

  • May replenish nutrients of soil naturally
  • For example, legumes add Nitrogen to soil
  • Allows different microorganisms in the soil to thrive

Green Manure

  • Adds bulk and NPK to soil that slowly decomposes
  • Like a slow-release fertilizer   * Will have nitrogen, phosphorous, potassium, etc.

Limestone

  • Addition of limestone adds valuable calcium to soil
  • Increases pH, making soils less acidic

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