此牌组中的学习卡（32）

• What is soil?

  A dynamic system with a large ecosystem that has its own inputs, outputs, and storages.
  soil ecosystem
• What is fertile soil?

  Soil that can sustain crops and vegetation.
  soil fertility
• What is organic material in soil?

  Material derived from living organisms that contributes to soil fertility.
  soil organic
• What are minerals in soil?

  Inorganic substances that provide essential nutrients for plant growth.
  soil minerals
• What does impermeable mean?

  A property where liquid penetrates an object when interacted with.
  soil permeability
• What does permeable mean?

  A property where water does not make it into an object or organism.
  soil permeability
• What is leaching?

  Loss of soluble water plant nutrients from the soil due to rain or irrigation.
  soil leaching
• What is aeration in soil?

  The need for air gaps within the soil.
  soil aeration
• What is the main function of fertile soil?

  To sustain crops and vegetation

  To prevent water absorption

  To increase soil acidity

  To reduce nutrient availability
  soil fertility
• What happens during leaching?

  Increase of nutrients in soil

  Water retention

  Soil compaction

  Loss of soluble nutrients from soil
  soil leaching
• What is a soil profile?

  A model showing different levels of soil.
  soil profile
• What is biological mixing in soil?

  The process of organisms rearranging organic matter through their movement and activity.
  soil biology
• Which organisms are known for biological mixing?

  Earthworms, as they move around the soil.
  soil earthworms
• What is a seed bank?

  Soil stores seeds that are dropped when plants reproduce; some seeds remain inactive until conditions are right.
  soil seeds
• What nutrients does soil store?

  Nitrogen, potassium, phosphorus, calcium, sulphur, iron.
  soil nutrients
• What do biochemical cycles involve?

  Energy flows through the system and dissipates as heat, while chemical elements are recycled.
  biochemistry cycles
• What is resource security?

  The ability of societies to ensure long-term availability of natural resources to meet demand.
  resources security
• What is terracing?

  Building along contour lines in hilly and mountainous regions under population pressure.
  land terracing
• What is contour ploughing?

  Digging into soil and turning it over, which deeply aerates the soil.
  land ploughing
• What is bunding?

  Creating raised embankments or ridges along the contours of a field using soil and stones.
  land bunding
• What are cover crops?

  Crops grown over the soil to protect and enrich it.
  land cover_crops
• What is green manure?

  Crops grown specifically to be dug back into the soil to add nutrients.
  land green_manure
• What is composting?

  Decomposing organic material into humus, including animal manure and crop residue.
  land composting
• What is humus?

  A stable nutrient-rich substance that enhances soil.
  agriculture soil
• What is marginal land?

  Land of little use for agriculture; crops produced are worth less than the land's price.
  agriculture land
• What does over grazing refer to?

  Livestock that overconsume vegetation in a specific area.
  agriculture livestock
• What is over cropping?

  Exhausting land by growing too many crops.
  agriculture crops
• What does field fallow mean?

  Soil left to rest for a growing season, allowing prior vegetation to decompose.
  agriculture soil
• What is crop rotation?

  Growing a series of different types of crops in the same area across different seasons.
  agriculture crops
• What is mixed cropping?

  Also known as polyculture; planting many crops beside one another.
  agriculture crops
• What does agroforestry involve?

  Integration of crops and livestock with trees and shrubs.
  agriculture forestry
• What is reduced tillage?

  Placing topsoil below the surface to allow crops to rot and provide nutrients.
  agriculture soil