Environmental Impacts of Agricultural Land Use (College Board AP® Human Geography)

Impacts of Agricultural Land Use

• Agricultural land use has significant impacts on the environment, including:

  • pollution

  • desertification

  • soil salinization

  • climate change 

• Heavy agricultural production can lead to a decrease in environmental sustainability

Environmental impacts in less developed countries

• habitat loss

  • Habitat loss results from the destruction of the natural landscape to make way for agricultural production and it causes a loss of biodiversity

• decreased water quality

  • Chemicals used for pesticides and fertilizers can seep into the water supply, damaging water quality and affecting wildlife

• increased wetlands

  • Water-dependent agriculture, such as wet rice farming, can lead to an increase in the amount of wetlands, which can benefit birds and other wildlife

• changes to natural landscapes

  • Changes to natural landscapes to make them more suitable for agricultural production include terracing, diversion of waterways, and deforestation

• changes in soil quality

  • Some farming types, such as burning rice straw, improve the soil quality

• changes in air quality

  • Smoke from burning rice straw or sugar cane, and methane from decomposition, cause air pollution

Environmental impacts in more developed countries

• decreasing air quality

  • Agricultural chemicals, especially as a result of aerosolized crop dusting, have a negative effect on air quality

• decreasing water quality

  • Chemical pollution and runoff also negatively affect water quality

• decreasing soil quality and erosion

  • Soil quality is negatively affected as a result of erosion and nutrient loss

  • Monocropping can cause soil exhaustion, loss of nutrients in the soil, and accumulation of chemicals

• modified biodiversity

  • The destruction of natural grasslands and wetlands to make way for large agricultural production areas decreases biodiversity, as both plant and animal species decrease or disappear 

  • In addition, monocropping results in a decrease in crop variety.

  • Heavy pesticide use creates superbugs that are resistant to pesticides and harms birds and other wildlife

• decreasing water availability

  • Overuse of water to irrigate crops can result in the depletion of ground aquifers, streams, and other waterways

• biodiversity loss which results from habitat destruction

  • The clearing of forests and grasslands for agricultural purposes reduces available wildlife habitats and causes a decrease in plant and animal life

  • Monoculture also contributes to biodiversity loss, as it reduces the genetic diversity of crops and makes them more vulnerable to pests and disease

Image: Terraced farming

Climate change

• The use of pesticides and fertilizers contributes to pollution of the:

  • air

  • water

  • soil

• In addition, methane emissions from livestock farming cause significant greenhouse gas buildup, which contributes to climate change

• Deforestation and the extensive use of fertilizers also contribute to climate change

Desertification & Soil Salinization

• Desertification refers to the process by which arable land becomes increasingly arid and “desert-like”

  • This causes the land to be unproductive for agricultural purposes

• Desertification is often the result of human actions that decrease soil nutrients, turning the soil into a dust-like substance unable to support agriculture. For example:

  • overgrazing

  • lack of crop rotation

  • poor irrigation practices

  • cutting down trees 

• The following locations are at high risk of desertification:

  • the Sahel

  • the Middle East

  • the Western United States 

• Soil salinization refers to the accumulation of salts in the soil from improper irrigation methods, which reduces soil fertility and makes it unsuitable for plant growth

Conservation Efforts

• Though the negative effects of large-scale agricultural production are the result of human activity, people can undertake conservation efforts to preserve and protect the environment

• These practices include:

  • soil conservation

  • water management

  • organic farming

  • supporting sustainable agriculture and fisheries

• Soil quality can be conserved by engaging in practices such as crop rotation and cover crops so that the soil does not become exhausted

• Water can be more effectively managed through:

  • the installation of efficient irrigation systems that use less water

  • protecting water sources through legislation

• Organic farming minimizes the use of chemical fertilizers, pesticides, and herbicides which reduces pollution and biodiversity loss, and maintains soil health