Lesson 7: Human Activities that Affect Soil Quality and Quantity

Soil

• the organic and inorganic materials on the surface of the earth that provide the medium for plant growth

• develops slowly over time and is composed of many different materials through the process of weathering

• Sustaining Life on Earth

• Water Purification

• Nutrient Recycling

• Biodiversity

Why is Soil Considered a Necessary Resource?

Sustaining Life on Earth

• helps sustain life on Earth including humans, animals and plants

Water Purification

• soil helps purify, or clean water as it drains through the ground and into rivers, lakes, and oceans.

Nutrient Recycling

• decomposers in soil helps recycle nutrients

Biodiversity

• provides a home for a variety of living things

• Loss Of Nutrients

• Salinization

• Acidification

• Pollution

• Compaction

Soil Degradation Processes Cause By Erosion

Loss of Nutrients

• refers to the depletion of essential elements and compounds in the soil, particularly macronutrients and micronutrients

Salinization

• the process by which water-soluble salts accumulate in the soil

Acidification

• occurs when the soil's pH level becomes excessively acidic often due to factors like acid rain or excessive use of acidic fertilizers

Soil Pollution

• refers to the introduction of harmful substances into the soil, including chemicals, heavy metals, pesticides, and industrial waste

Soil Compaction

• the process by which soil particles are compressed and packed more tightly together, reducing pore space and limiting air and water movement

• Farming        

• Waste Disposals

• Construction Of Structure

• Mining            

• Illegal Logging

5 Major Human Activities That Cause Soil Degradation

 Farming 

• one of the traditional sources of income in our country done by planting crops or raising livestock

Positive Effects of Farming

• Application of herbicide has a positive benefit on soil health

• Lime and mineral fertilizers provides stable optimum growing conditions for plants

• Organic manures and other organic fertilizers makes the soil healthy and good for planting.

• Irrigation/drainage water makes the soil healthier and more suitable for planting

Tillage

Construction of Structure

Waste Disposal

Mining 

Illegal Logging

Negative Effects of Farming

Tillage

• can cause direct damage to soil microorganisms and potentially expose those to new  predators 

Construction of Structure

• Construction activities, such as grading and filling, reduce soil quality on construction sites.

• Land use conversion usually done to support urbanization activities can cause rapid soil degradation and sedimentation.

Waste Disposal

• Soil pollution happens when hazardous chemicals from human and industrial sewage are carelessly disposed of, altering soil’s natural health and quality

Mining

• Some methods cause soil loss.

  • The digging of strip mines and open-pit mines involve the removal of plants and soil from the surface of the ground. By exposing rocks and minerals to the air and to rainwater, these forms of mining speed up the rate of chemical weathering.

• In operations that expose sulfide minerals, the increased chemical weathering causes a type of pollution known as acid drainage

Illegal Logging

• Abusive cutting of too many trees in the forest without replanting new seedlings, will eventually lead to soil erosion.

Erosion

• the movement of weathered rock and soil from one place to another 

• powerful enough to level hills and mountains. 

gravity, running water (plays the biggest part), ice, wind and people.

The agents of erosion

Wind Erosion

• happens when winds carry vast quantity of fine soil particles and sand away from a region, spreading it over and adjoining cultivated land destroying their fertility

Sheet Erosion

• the removal of thin layers of soil because of the surface run off and rain. 

Rill Erosion

• The removal of soil by the action of concentrated running water

• Creates numerous centimeter deep tiny channels called rills, which carry water during storms

Gully Erosion 

• The removal of soil in water channels or drainage lines 

• The gullies gradually multiply and spread over wide areas

Forest Protection

• Trees as well as other plants and vegetation in the forest are important in the creation of new soil as leaves and other vegetation rot and decompose. Hence, soil qualities are ensured when forest are protected and conserved. 

Buffer Strips

• strips or corridors of permanent vegetation used to reduce water and wind erosion. They provide protection where stream banks exist.

No-Till Farming

• It is an approach that allows crops to remain in place for a season. This keeps the soil from being left bare and unprotected.

Fewer Concrete Surfaces

• Lots of concrete surfaces, especially in residential areas make it difficult for water to get to the soil. Using paving stones for patios and gardens work to protect the soil.

Plant Windbreak Areas

• are composed of shrubs, plants and trees. These will work together to slow the force of wind over ground areas. This is a method that can also work to prevent erosion of the soil.

Terrace Planting

• This type of planting is done by maximizing the topography of the land. It benefits from the way the rain water flows naturally. This is a way to protect the soil from erosion.

Plant Trees

• is a good conservation method. As the tree grows, its roots become even more secure in the soil. This soil is protected in numerous ways because of the trees’ existence. Erosion is prevented from this planting process.

Crop Rotation

• This is a process that works to conserve soil. It is accomplished by planting and growing a serious of different crops in the same soil. This process prevents overgrowth of pathogens and a lack of fertility in the soil, overall.