SoilSoil

Chapter 7, Section 3 & 4Chapter 7, Section 3 & 4

SoilSoilA loose mixture of rock A loose mixture of rock

fragments, organic fragments, organic material, water, and air material, water, and air that can support the that can support the growth of vegetation.growth of vegetation.

Parent RockParent Rock

A rock formation A rock formation that is the source of that is the source of mineral fragments mineral fragments in soilin soil

BedrockBedrock

Layer of rock Layer of rock beneath soilbeneath soil

Transported soilTransported soilSoil that can be blown or Soil that can be blown or washed away from its washed away from its parent rockparent rock

Soil TextureSoil TextureThe soil quality that is based The soil quality that is based

on the proportions of soil on the proportions of soil particles.particles.

Soil StructureSoil StructureThe arrangement of soil The arrangement of soil particles.particles.

InfiltrationInfiltrationAbility of water to move Ability of water to move through soilthrough soil

HumusHumus

The dark, organic The dark, organic material formed in soil material formed in soil from the decayed from the decayed remains of plants and remains of plants and animals.animals.

LeachingLeaching

Removal of substances Removal of substances that can be dissolved that can be dissolved from rock, ore, or layers from rock, ore, or layers of soil due to passing of of soil due to passing of waterwater

Draw the different soil horizons pg. 196Draw the different soil horizons pg. 196

This horizon consists of the topsoil. Topsoilcontains more humus than any othersoil horizon. Soil in forests often has aO horizon. This layer is made up of litterfrom dead plants and animals.

This horizon experiences intense leachingof nutrients.

This horizon collects the dissolved substancesand nutrients deposited from theupper horizons.

This horizon is made of partially weatheredbedrock.

This horizon is made of bedrock that haslittle or no weathering.

Water dissolvesand carriesnutrients in thetopsoil throughthe horizons.This is calledleaching orthe removal ofsubstances thatcan be dissolvedfrom rock or layersof soil dueto the passing ofwater.

Soil MoistureSoil MoistureSoil moisture is important Soil moisture is important

because…because…the amount of moisture in the amount of moisture in

the soil determines the soil determines whether precipitation will whether precipitation will infiltrate or run off the soil.infiltrate or run off the soil.

Soil pHSoil pH

Soil pH influences…Soil pH influences…Which nutrients will be Which nutrients will be available to plants from available to plants from the soil.the soil.

Soil ColorSoil Color Soil color is related to soil fertility.Soil color is related to soil fertility. Soils that are black or dark brown Soils that are black or dark brown

usually contain organic matter and usually contain organic matter and are fertile.are fertile.

Reddish or yellowish soils often Reddish or yellowish soils often contain oxidized iron and are fertile.contain oxidized iron and are fertile.

Soils that are whitish may contain Soils that are whitish may contain salts which make soils unsuitable for salts which make soils unsuitable for farming.farming.

Tropical Rainforest ClimatesTropical Rainforest Climates

The air is very humid and the The air is very humid and the land receives a large amount of land receives a large amount of rain. rain.

Warm temperatures allow crops Warm temperatures allow crops to grow year-round.to grow year-round.

Tropical rain forest soils are Tropical rain forest soils are nutrient poor.nutrient poor.

DeforestationDeforestationClearing trees from an Clearing trees from an area without replacing area without replacing themthem

Desert ClimatesDesert ClimatesDeserts get very little rainDeserts get very little rainLack of rain makes it harder for Lack of rain makes it harder for

the soil to support plant and the soil to support plant and animal life.animal life.

Some groundwater is available Some groundwater is available but as soon as it reaches the but as soon as it reaches the surface it evaporates.surface it evaporates.

Land DegradationLand DegradationOccurs when either natural Occurs when either natural

processes or human activity processes or human activity damages land to the point it can damages land to the point it can no longer support plants and no longer support plants and animals.animals.

Desertification-a process where Desertification-a process where land becomes more desertlike.land becomes more desertlike.

Temperate forest and grassland Temperate forest and grassland climateclimate

Most of US has a temperate Most of US has a temperate climate.climate.

An abundance of weathering An abundance of weathering occurs in temperate climates.occurs in temperate climates.

Thick, fertile soils develop.Thick, fertile soils develop.Temperate soils are some of the Temperate soils are some of the

most productive soils in the most productive soils in the world.world.

Arctic ClimateArctic Climate So little precipitation occurs that they So little precipitation occurs that they

are like cold deserts.are like cold deserts. Soil is thin and unable to support Soil is thin and unable to support

many plants.many plants. Low soil temperatures so Low soil temperatures so

decomposition of plants and animals decomposition of plants and animals happens more slowly or stops happens more slowly or stops completely.completely.

Soil ConservationSoil ConservationMethod to maintain Method to maintain the fertility of the soil the fertility of the soil by protecting the soil by protecting the soil from erosion and from erosion and nutrient lossnutrient loss

Importance of SoilImportance of Soil

Soil provides minerals and other Soil provides minerals and other nutrients for plants.nutrients for plants.

If the soil loses these nutrients, then If the soil loses these nutrients, then the plants will not be able to grow.the plants will not be able to grow.

Animals get nutrients from plants Animals get nutrients from plants and plants get their nutrients from and plants get their nutrients from soil.soil.

TranspirationTranspirationProcess in which plants Process in which plants take in water through take in water through their roots and release it their roots and release it through their leavesthrough their leaves

Soil and organismsSoil and organisms1 gram of soil can contain as 1 gram of soil can contain as

many as 1 billion organisms. many as 1 billion organisms. Examples: plants, fungi, worms, Examples: plants, fungi, worms,

insects, and small mammals.insects, and small mammals.Each plays an important role in Each plays an important role in

the soil ecosystem.the soil ecosystem.

ErosionErosionProcess by which wind, Process by which wind, water, ice, or gravity water, ice, or gravity transport soil and transport soil and sediment from one sediment from one location to anotherlocation to another

SalinizationSalinizationThe accumulation of The accumulation of salts in soil. Major salts in soil. Major problem in many parts problem in many parts of the world where of the world where rainfall is little and salt is rainfall is little and salt is naturally in the soilnaturally in the soil

Contour plowingContour plowing

Farmers plow Farmers plow across the slope of across the slope of the hills instead of the hills instead of up and downup and down

TerracingTerracingFarmers change Farmers change one steep hill into a one steep hill into a series of small, flat series of small, flat fieldsfields

Crop rotation/cover cropsCrop rotation/cover crops

Planting different crops to help keep Planting different crops to help keep certain nutrients from being certain nutrients from being depleted.depleted.

Crops that are planted between Crops that are planted between harvests to replace certain nutrients harvests to replace certain nutrients and prevent erosion.and prevent erosion.

No-till farmingNo-till farming A farmer harvest a crop without A farmer harvest a crop without

turning over the soil. turning over the soil. The farmer leaves the remains of a The farmer leaves the remains of a

newly harvested crop on the ground newly harvested crop on the ground and plants the next crop in these and plants the next crop in these remains. remains.