Agriculture and Soil Resources

Soil is a mixture of eroded rock, minerals, partially decomposed organic matter, and other materials. It's essential for plant growth, so it's the foundation of all land ecosystems. Soil is important for other reasons as well. For example, it removes toxins from water and breaks down wastes.


While soil is considered a renewable resource, it takes a very long time to form (up to hundreds of millions of years). So, for human purposes, it's considered a nonrenewable resources. It can be depleted of nutrients through careless use, poor farming practices, wind and water erosion. Farmers were forced off their lands during the Dust Bowl in the 1930s when the rains stopped and the topsoil blew away. 


Farming can accelerate soil erosion because of the amount of land that is farmed and how much farming practices disturb the ground. Farmers remove native vegetation and then plow the land to plant new seeds. While these farmlands lay fallow, wind and water can eroded the exposed soil quickly. Also, tractor tires make grooves, which are natural pathways for water to erode. Grazing similarly accelerates soil erosion. Animals expose soil by removing the plant cover in an area and churn up the ground with their hooves. 


Agriculture provides food for the world's human population. Most of the best land for farming is already being cultivated. With human populations continuing to grow, it is extremely important to protect our soil resources. There are several strategies that farmers can follow to prevent soil loss, such as crop rotation, terracing fields, growing cover crops, and planting wind breaks around fields to buffer soil from wind erosion.


Watch the following video:


Sources: Soil Erosion. Retrieved from http://www.ck12.org/book/CK-12-Earth-Science-Concepts-For-High-School/r16/section/13.5/ on December 27, 2013. and Avoiding Soil Loss. Retrieved from http://www.ck12.org/book/CK-12-Earth-Science-Concepts-For-High-School/r16/section/13.6/ on December 27, 2013. and USOE OER Resource Guide for earth Systems.