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Words
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Definition
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Clues to help remember
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Renewable
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A resource that can be replaced in a human lifetime.
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Trees are an example of a renewable resource.
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Exhaustible
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A resource such as air or water that cannot be used over and over and can be used up.
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Air, water, coal and oil are all exhaustible.
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Conservation
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The saving of resources by using them carefully.
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Farmers practice conservation to save the soil so they can continue to grow crops.
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Topsoil
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The top layer of soil made up of the smallest grains and the most humus.
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The richest layer of soil.
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Bedrock
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The solid rock under soil that is made of different minerals in different places.
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Weathering breaks down bedrock into soil.
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Loam
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A type of topsoil that is rich in minerals and has lots of humus.
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Most farm soils are loam because it has a lot of water and air for plants.
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Nonrenewable
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A resource, such as coal or oil that will be used up someday.
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Coal, oil iron, and copper are some examples of nonrenewable resources.
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Inexhaustible
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A resource such as air or water that can be used over and over and can’t be used up.
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Water, air and the sun are inexhaustible resources.
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Soil Profile
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Materials that make up the soil.
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Soil is a mixture of four different materials: weathered rock, humus, air and water.
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Subsoil
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The layer of soil under the topsoil.
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Subsoil has larger grains and less humus than topsoil.
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Clay
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A type of soil made up of very small grains; it holds water well.
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When clay soil dries after a rain, it often forms hard clods. When the clods are broken up, they feel like powder.
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Humus
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The part of the soil made up of decayed parts of once-living things.
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Humus is dark and soft. It contains much of what plants need for growth.
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Natural Resources
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Materials found in nature that living things use.
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Water, air, trees, minerals and soil are all resources, as are metals, coal, gasoline and oil.
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Compost
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A mixture of material from once-living things.
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People use food scraps and yard clippings to make compost. Then add it to the soil to make plants grow better.
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Recycle
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To reuse a resource to make something new.
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Recycling makes resources last longer.
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