H UMAN E FFECTS

SC S TANDARDS 7.EC 25 A. 2 Construct explanations of how soil quality (including composition, texture, particle size, permeability) affects the characteristics of an ecosystem using evidence from soil profiles Describe natural processes that change Earth’s surface Interactions among changes in the environment due to natural hazards (including landslides, earthquakes, mountain building, new land being formed, weathering, erosion, sedimentation, soil formation).

I S S OIL A N ECESSARY R ESOURCE ? Soil helps sustain life on Earth because it supports the growth of plants. Plants are responsible for providing food, clothing, lumber, medicines, and many other things to people. Soil also helps filter water and is home to many organisms

L AND P RACTICES THAT C AN H ARM S OIL Using fertilizers can make it difficult for decomposers that live in the soil to produce nutrients

L AND P RACTICES THAT C AN H ARM S OIL Clearing land/removing plant cover cause soil to be exposed to rain and wind. This leads to soil being washed or blown away.

L AND P RACTICES THAT C AN H ARM S OIL Overgrazing occurs when farm animals eat large amounts of plant cover This results in soil being washed or blown away easily.

L AND P RACTICES THAT C AN H ARM S OIL Mining: Results in removal of plant cover Can produce sulfuric acid which can drain out and pollute the surrounding soil

L AND P RACTICES THAT C AN P RESERVE S OIL Crop Rotation- planting different crops on the same field in different growing seasons help the soil maintain nutrients needed for plant growth

L AND P RACTICES THAT C AN P RESERVE S OIL Conservation tillage disturbs the soil less by reducing the number of times fields are tilled or plowed in a year.

L AND P RACTICES THAT C AN P RESERVE S OIL Terraces are flat, step- like areas built on a hillside to hold rainwater and prevent it from running downhill.

L AND P RACTICES THAT C AN P RESERVE S OIL Contour Plowing happens along curves or contours of a slope. Helps channel rainwater so it does not carry soil downhill

L AND P RACTICES THAT C AN P RESERVE S OIL Windbreaks are rows of trees planted between fields to break or reduce the force of winds that can carry soil away.

R ECAP 1. Why is soil a necessary resource? 2. Describe 2 ways that land practices can harm soil. 3. Describe 2 ways that soil can be preserved.