Land is an important natural resource that people rely on to meet many of their needs. However, the ways humans use land can have significant effects on the environment. One of the most important uses of land is farming, which provides the food people depend on to survive.  To increase crop production and control pests, farmers often use chemical fertilizers, herbicides, and pesticides. Fertilizers contain nutrients such as nitrogen, potassium, and phosphorus that help plants grow. However, these chemicals do not always stay in place. They can seep into the soil or be carried by runoff into nearby streams and lakes, where they may harm ecosystems.

To reduce these environmental impacts, many farmers use sustainable farming practices that help protect soil and water. For example, crop rotation involves planting different crops each season to improve soil health and maintain nutrients. In addition, contour plowing follows the natural contours of the land, which helps reduce gravity-driven soil movement.  Another method, no-till farming, leaves crop stalks and roots in place after harvesting, helping to keep soil in place and reduce erosion. Similarly, terracing creates step-like levels on hillsides, reducing steep slopes and preventing runoff and topsoil from washing away.

Land is also used to raise livestock for meat and dairy products. However, when too many animals graze in one area, overgrazing can occur. Livestock activity compacts the soil and reduces vegetation cover, leaving the ground more exposed to wind and water. This increases the likelihood of soil erosion, where valuable topsoil is carried away.

Another way humans impact land is through deforestation, the clearing of forests. Trees are cut down for wood used in buildings, fuel, and paper products. Trees also absorb carbon dioxide while they are alive, so removing large numbers of trees can increase carbon dioxide levels in the atmosphere. In addition, deforestation can lead to soil erosion and the loss of habitats for many plants and animals.

Human development also changes the land. The construction of highways, parking lots, and buildings covers soil with pavement and concrete. These surfaces prevent water from soaking into the ground and replenishing underground water supplies. Landfills are another example of human impact on land. Landfills are areas where garbage is buried and covered with soil. Many materials placed in landfills do not decompose and may remain there for long periods. As landfills fill up, new ones must be created. To prevent harmful substances from leaking into the ground, many landfills are lined with plastic, concrete, or clay-rich soil.

Because human activities can harm land resources, efforts have been made to protect them. Natural preserves are areas set aside to protect land and wildlife from environmental damage. Another important practice is recycling, which involves converting used materials into new and useful products. Recycling helps reduce the amount of waste sent to landfills and conserves natural resources.

Review:

1. How does our use of land impact the environment?
2. Why is deforestation a problem?
3. Why were nature preserves created?