Soil Formation and Erosion Quiz

Soil Formation, Erosion, Composition, and Properties

• Soil formation begins when parent material (underlying rock) weathers, moves, and deposits.
• Soil horizons are layers of soil categorized by composition and organic content.
  • O Horizon: Organic layer, rich in decomposed plant matter (humus)
  • A Horizon: Topsoil, a blend of organic matter and minerals, crucial for plant growth.
  • E Horizon: Leaching layer, where minerals are leached out
  • B Horizon: Subsoil, where minerals and nutrients accumulate from above layers.
  • C Horizon: Weathered parent material, partially disintegrated rock.
  • R Horizon: Bedrock, the unweathered rock layer beneath the soil.
• Erosion is the wearing away of soil by natural processes.

Nutrient Cycles and Eutrophication

• Nitrogen is essential to plants, but most forms are unusable until converted through a process.
• Nitrogen fixation converts atmospheric nitrogen into ammonia.
• Ammonification decomposes dead matter into ammonia.
• Nitrification converts ammonia into nitrate (usable by plants).
• The phosphorus cycle lacks an atmospheric component, primarily found in rock and minerals.
• Weathering releases phosphorus from rocks into the soil and water, then absorbed by plants.
• After organisms die, phosphorus is returned to the soil.
• Eutrophication is nutrient enrichment, specifically nitrogen and phosphorus, in bodies of water.
  • Algal blooms occur due to increased nutrients, and decaying algae deplete oxygen levels resulting in hypoxic conditions and die-offs of marine life.

The Green Revolution and Agricultural Practices

• The Green Revolution was an advancement in agricultural strategies to improve food production.
• Mechanization, GMOs, fertilization, irrigation, and pesticides were key strategies.
• Mechanization increased efficiency but relies heavily on fossil fuels.
• GMOs increased yields and pest resistance, but can reduce genetic diversity.
• Fertilization contributes to greater crop yields, but excessive use can negatively affect the environment.
• Irrigation increases crop yields, but water resources are strained.
• Pesticides kill pests, but can lead to resistance and environmental damage.
• Agricultural practices can negatively impact the environment.

Irrigation Methods

• Irrigation, the use of freshwater to water crops, accounts for 70% of freshwater consumption.
• Types of irrigation include drip irrigation (efficient), furrow irrigation (inexpensive), flood irrigation (20% water loss), and spray irrigation.

Pest Control Methods and Integrated Pest Management (IPM)

• Common pest control methods include pesticides, which can lead to pest resistance.
• Integrated Pest Management involves a combination of strategies (biological, physical, and limited chemical) to manage pest populations.
• This approach aims to minimize environmental disruptions.
• Bioaccumulation is the process where harmful substances accumulate within organisms, while biomagnification involves an increase in concentration as substances move through trophic levels.

Meat Production Methods

• Concentrated Animal Feeding Operations (CAFOs) use feeding strategies to efficiently increase livestock yield for slaughter, but have negative environmental consequences.
• Free-range grazing allows animals to graze on grass, though it requires higher land areas and can be more expensive.

Sustainable Agriculture

• Sustainable agriculture aims to prevent soil erosion and ensure agricultural productivity.
• Methods of soil conservation include contour plowing, windbreaks, and perennial crops.
• Rotational grazing is a method to prevent overgrazing.
• Reducing meat consumption decreases emissions related to livestock production.

Vocabulary

• Pesticides: Chemicals used to kill pests
• Herbicides: Chemicals used to kill plants
• Fungicides: Chemicals used to kill fungi
• Rodenticides: Chemicals used to kill rodents
• Insecticides: Chemicals used to kill insects.