Nature of Water & Soil• Most of the Earth’s surface is covered with water.• Our bodies & plants & animals are about 90% water.• We can only survive a few days without potable

water.– Potable – Drinkable, free of harmful chemicals and

organisms.• Water is an essential nutrient for all plants &

animals• Water transports nutrients & carries away waste

products.• Water cools the body

The Universal Solvent• Water has been described as the Universal

Solvent– Universal Solvent – material that dissolves or

otherwise changes most other materials• Nearly every substance will rust, corrode,

decompose, dissolve, or yield to the presence of water.

• Some minerals in water are healthful or desirable; others are toxic & undesirable chemicals or minerals.

Fresh vs. Salt Water• Most water on the Earth is not fresh water

& not suitable for humans to drink or use except for transportation.– Fresh water – water that flows from the land

to oceans and contains little or no salt.– Domestic Use – household use.– Tidewater – water that flows up the mouth of

a river as the ocean tide rises or comes in• Salt water is not fit for animal consumption

or plant irrigation.

The Water Cycle• Moisture evaporates from land, plant

leaves, freshwater sources and the seas to form clouds

• Clouds remain in the air until warm air masses meet cold air masses.

• Change causes water vapor to change to a liquid and fall as rain, sleet or snow.

• This is known as the water cycle.– Water Cycle – cycling of water among water

sources, atmosphere, and surface areas.

Land• Land provides solid foundations for buildings,

nutrition & support for plants and space for work & play and storage for water.

• Much of the Earth’s crust is too rocky or has an incorrect balance of nutrients for crop production.– Deserts – areas with continuous, severe water

shortages– Irrigation – addition of water to plants to

supplement the water provided by rain or snow.

Relationships of Land and Water• Precipitation – formation of rain and snow.• Evaporation – changing from a liquid to a

vapor or gas.• Watershed – large land area in which water is

absorbed from rain or melting snow, and from which water drains as it emerges from springs and moves into streams, rivers, ponds and lakes.– Acts as a storage system by absorbing excess

water and releasing it slowly throughout the year.

Relationships of Land and Water• Land serves as a container or reservoir for

water.• Water soaks down into the soil and forms a

water table.– Water table – level below which soil is saturated or

filled with water.• Water may run out onto the surface at a lower

elevation in the forms of springs.• Water moves upward in the soil from the

water table to provide water for plant roots.

Relationships of Land and Water• Types of Ground Water– Saturated – when all spaces or pores are filled

with water.– Free or Gravitational Water – water that

drains out of soil after it has been wetted.• Feeds wells and springs.

– Capillary Water – water held by soil particles and available for plant use

– Hygroscopic Water – water that is held too tightly for plant roots to absorb.

Major Threats to Water Quality

• Chemicals• Manure• Household products – paint, varnish,

household cleaning products.• Excessive amounts of fertilizer• Pesticides• Gas, fuel or oil dumping

IMPROVING WATER QUALITY

• Improvement of water quality can be achieved by:– Proper Land Management– Careful Water Storage and Handling– Appropriate Use of Water

PRACTICES THAT HELP REDUCE WATER POLLUTION

• Save clean water• Dispose of household products carefully• Care for lawns, gardens and farmland carefully• Practice sensible pest control• Control water runoff from lands, gardens, feedlots,

fields• Control soil erosion• Avoid spillage or dumping of gasoline, fuel, or oil on

the ground or in storm drains• Keep chemical spills from running or seeping away• Properly maintain your septic system

LAND EROSION• Land erosion is a serious problem

worldwide.– Erosion — wearing away.

• Both wind and water are capable of wearing away soil

• Extensive damage from soil erosion comprises the food and fiber production capabilities of large nations

SOIL EROSION FACTS• Soil scientists report it takes 300-500 years

for nature to develop 1 inch of topsoil from bedrock.

• There are 50 acres of tropical rain forest lost every minute through “slash & burn”

• Amount of soil dumped into the Mississippi River Delta every day would fill a freight train 150 miles long.

EROSION – A NATIONAL PROBLEM

• Each year, about 1.6 billion tons of soil are worn away from 417 million acres of US farmland and deposited into lake, rivers and reservoirs

• According to the USDA, 41 million acres (10%) of the nation’s cropland are highly eroded at rates of 50 or more tons per acre per year

• Growing Concern – Contamination of groundwater– Aquifer – water-bearing rock formation

THINK ABOUT THIS1 Acre of Highly Erodible Soil

You would have to load and carry1 – 30 lb Bucket of Soil

Every 30 SecondsWorking 8 hours per day

For over 4 DaysTo Replace the amount of soil lost from

1 acre in one year

Examples of Erosion

• Grand Canyon• Chimney Rock• Scotts Bluff

SHEET EROSION

Sheet erosion — removal of soil from broad areas of the land.

GULLY EROSIONGully erosion — removal of soil to form relatively narrow and deep trenches known as gullies.

RILL EROSIONRill erosion – loss of soil on sloping land where small channels are formed by running water

Conservation Practices• Cover crop — close-growing crop planted to

protect the soil and prevent erosion. • Mulch — material placed on soil to break the fall

of raindrops (preventing erosion), prevent weeds from growing, or improve the appearance of the area.

Conservation Practices• No-till — seed is planted directly into the residue

of the previous crop, without exposing the soil surface.

• Conservation tillage — techniques of soil preparation, planting, and cultivation that disturb the soil the least, leaving the maximum amount of plant residue on the surface.– Plant residue — plant material that remains when a

plant dies or is harvested.

Conservation Practices• Contour practice — operations such as plowing,

disking, planting, cultivating, and harvesting across the slope and on the level.– Contour — level line around a hill.

• Strip cropping — alternating strips of row crops with strips of close-growing crops.

Conservation Practices• Crop rotation — planting of different crops in

a given field every year or every several years.• Grass waterway — strip of grass growing in

the low area of a field where water can gather and cause erosion.

Conservation Practices• Terrace — soil or wall structure built across the

slope to capture water and move it safely to areas where it will not cause erosion.

RECOMMENDED PRACTICES TO REDUCE OR PREVENT WIND &

WATER EROSION• Keep soil covered with growing plants• Cover the soil with mulch• Utilize conservation tillage methods• Use contour practices in farming, nursery production and

gardening• Use strip cropping on hilly land• Rotate crops• Increase organic matter in the soil– Organic matter — dead plant and animal tissue that

originates from living sources such as plants, animals, insects, and microbes.

RECOMMENDED PRACTICES TO REDUCE OR PREVENT WIND &

WATER EROSION• Provide the correct balance of lime and fertilizer– Fertilizer — material that supplies nutrients for plants.

• Establish permanent grass waterways• Construct terraces• Avoid overgrazing– Overgrazing — damage to plants or soil due to animals

eating too much of the plants at one time or reducing the plant’s ability to hold soil or recover after grazing.

• Use land according to a conservation plan– Conservation plan — a plan developed by soil and

water conservation specialists to use land for its maximum production and water conservation without unacceptable damage to the land.