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14sec4

  1. 1. 14.4 Sustainable Agriculture
  2. 2. Why sustainable agriculture? <ul><li>Modern agriculture is driven by economics and trade </li></ul><ul><li>To be competitive has meant: soil erosion, deforestation, desertfication, hunger, war and global environmental damage </li></ul><ul><li>Population is incresing and so food production must also </li></ul><ul><li>SUSTAINABLE AGRICULTURE REDUCES SOME OF THIS NEGATIVE ENVIRONMENTAL IMPACT </li></ul>
  3. 3. Sustainable Agriculture <ul><li>Based on crop rotaion, reduced soil erosion, integrated pest management and minimal use of soil additives ( fertilizers) </li></ul><ul><li>Also called regenerative farming </li></ul><ul><li>Idea of it is to maintain the environment so fertility of soil, and minimal environmental damage allows the agriculture to continue indefinitely </li></ul>
  4. 4. Crop Rotation <ul><li>Changing the type of crop planted in a field on a regular basis </li></ul><ul><li>Cycle of rotation is from 1-6 years </li></ul><ul><li>Helps keep the soil from getting depleted of minerals ( especially N) </li></ul><ul><li>Legumes restore the N in the soil ( remember N-cycle?) </li></ul><ul><li>Reduces the amount of fertilizer needed </li></ul><ul><li>Often legumes can be planted as cover crops-nonfood plants between growing seasons- helps replenish the soil and prevent erosion </li></ul>
  5. 5. Erosion <ul><li>Natural process where soil gets transported from an ecosystem or region </li></ul><ul><li>Wind and water are main agents </li></ul><ul><li>Erosion is disastrous to farming-rich topsoil is what gets eroded- this is where the nutrients are in the soil </li></ul>
  6. 6. Reducing Erosion <ul><li>Careful irrigation: drip systems which apply water directly to roots of plants prevents erosion </li></ul><ul><li>Reduce tillage ( tilling the soil is turning the soil over) </li></ul><ul><li>Tilling soil is done to get rid of weeds and pests, aerate the soil, improve drainage, and bring fresh nutrients to the surface; however it incrases eroison </li></ul>
  7. 7. Pest Management <ul><li>IPM- integrated pest management reduces use of pesticides by 90% in some areas </li></ul><ul><li>Makes use of natural predators like lady bugs, wasps, cerain bacteria and virus that affect insects </li></ul><ul><li>Indonesia-brown plant-hopper became resistant to pesticides and was destroying rice crop; President banned use of almost all pesticides; natural enemies of the plant hopper then took over and were ablt to keep the pest under control; famers now have higher crop yields </li></ul>
  8. 8. What caused the greatest famine in world history?

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