Table Of Contents Abstract Purpose  Hypothesis Experiment Design Materials Procedures Research Report Results Graphs Conclusion Bibliography

The manipulated variable is the type of erosion control product.  The responding variable is the amount of soil run-off that is collected.  To measure the responding variable I am using a triple beam balance

The purpose was to determine which erosion control product would slow erosion in a furrow irrigation system.  The experiment revealed straw worked better at both an 8-degree incline and at a 16-degree incline.

My hypothesis is accepted because I hypothesized that straw would work better in slowing soil erosion in a furrow irrigation system.  A question raised during the experiment was whether other types of vegetation would work as well as straw to slow soil erosion.  If I were to do this experiment again I would conduct more trials at different inclines, use different types of soil, and dried vegetation.

The manipulated variable is the type of erosion control product.  The responding variable is the amount of soil run-off that is collected.  To measure the responding variable I am using a triple beam balance.

Erosion is a natural process that occurs all over the world in different climates.  The erosion can be caused by environmental factors or by humans.  It has become a recognized problem.

Erosion is a natural process during which soil and rock are broken loose from the earth’s surface at one location and moved.  Erosion changes the land by wearing down mountains, filling in valleys, and making rivers appear and disappear. Normally the eroded material moves from a high place to a low place on the earth’s surface. It is usually a slow process that gradually occurs over thousands or millions of years.  But it can be speeded by human activities of farming and mining.  Wind, water, glacial ice, animals, and tools used by humans cause erosion.

Erosion begins with weathering.  In this process environmental factors break down rock and soil into smaller pieces and loosen then from the surface of the earth. Water, glaciers, and wind are the tree major agents in erosion.  A chief cause is the formation of ice.  As the water freezes inside the crack of the rock, it can break the rock apart.  Other major agents of weathering include chemicals, living organisms, and the movement of air, ice and water as well as heat from the sun.  After materials have been loosened by weathering can be moved to a new location.  For example, wind lifts loosened particles from the earth’s surface and can carry then over great distances.  Glaciers transport materials embedded in them.  Raindrops splash against sloping land move soil particles downhill.  Water currents carry materials down a riverbed or out to sea.  Erosion can be both helpful and harmful.  Its benefits include contributing to the formation of soil through the breaking down of rock.  It causes rich soil to be deposited in valleys and at the mouth of rivers.  Erosion has created some of the world most incredible geological formations, like the Grand Canyon.  The Grand Canyon has been created of millions of years of erosion of the Colorado River.
 
 

Erosion by water combines the weathering power of water with water’s ability to move rock.  Rainwater drains from the land into streams that flows downhill.  The moving water cuts into the land as it wears away the soil and rock.  The faster the river flows, the more rock and soil it sweeps away.  Bits of rock collected by the stream add to the grinding action.  The soft rock grinds away first, then the hard rock.  Sometimes this causes towering masses of hard rock towering on a plain.  The rock remains long after the disappearance of the water that wore away the soft rock.  When rivers reach the sea they leave behind the materials they picked up while flowing over the land.  At the mouths of some rivers the material forms in a triangular shaped deposit called a delta.  All along the seashore water gradually changes the shape of the land.  Waves and tides wear away the shore and create sand bars, beaches, cliffs, and headlands.  Water moving underground also changes the shape of the land.  Geysers shoot out of the earth and carry dissolved minerals to the surface.  Underground water dissolves rock and forms caves deep in the ground.

Erosion’s harmful effects are that it robs farmlands of its productive topsoil.  Because of this it is one of the leading threats to the food supply.  Erosion can wash valuable fertilizers from the farmland and carry pollution causing agricultural chemicals into lakes and rivers.  Eroded soil can clog irrigation ditches, ponds, and reservoirs.  Gullies caused by the flowing water may ruin fields by making them to small to farm with tractors and other equipment.  Forest cutting, over grazing, grading for highway use, urban land use or preparation for other large scale engineering projects also may speed the erosion of soil.

Although erosion is a natural process, things can be done to slow it.  The process of minimizing soil erosion is soil conservation.  Soil conservation is important because cultivation, deforestation, agricultural production, grazing, and other disturbances have increased over the last 100 years. The exact extent of soil erosion is not known particularly as far as the rate of soil movement is concerned.  It is said that everywhere in the world experiences erosion.  Soil erosion increases when land is cleared and cultivated because trees and other plants shield the soil from wind and rain.  Their roots and waste material from previous plants also help to hold soil in place.  Farmers can decrease erosion by using nontillage or conservation tillage techniques, in which wastes from previous crops remain in the soils surface.  Other methods include contour plowing, strip cropping and terracing.   Accelerated erosion may be endured by land practices, which denudes the soil surfaces of vegetation cover.  For example the planting of any crops on a slope without soil conservation practices will suffer fast erosion.  Planting other crops like small grain may slow fast erosion, especially where fields are kept bare between crops to store moisture.

Depletion of soil nutrients is obviously a part of soil erosion.  However, such depletion may take place in the absence of any noticeable signs of erosion.  The disappearance of naturally stored nitrogen, potash, phosphate, and some trace elements form the soil affects the usability of the soil for human purposes.  The natural fertility of the soil always is depleted over time is stuff is planted, but the amount of depletion dependent on management practices.

Irrigation is the artificial watering of land for growing crops.  Irrigation enables crops to grow in regions with inadequate precipitation.  The first irrigation system dates back to before 3000 BC, when canals and ditches were built to carry water from rivers to fields nearby in Egypt, Asia and the Middle East.  Later simpler devices were used to transfer water from rivers and streams into irrigation channels.  Today, most of the water used for irrigation is ground water or surface water.  Surface water comes from streams, rivers, and lakes.  Building a dam across a river causes large quantities of water to accumulate in an artificial river or reservoir.  This water can be used for irrigation in areas when rainfall is scarce.  Groundwater is form wells.  In some regions, fresh water for irrigation is obtained by desalination.  Canals, ditches, pumps, and pipes convey the water to the fields.
Irrigation is used in three types of climates.  In desert regions such as Egypt and the Southwestern United States, farming would be difficult without irrigation.  In regions like Italy or California, irrigation makes farming possible even during the dry months.  In moist regions such as the Eastern United States and Western Europe, irrigation maintains crop growth during droughts. In the Mid 1980’s about 550 million acres of land were under irrigation in the United States and two million acres in Canada.  The amount of water needs for farming depends on the type of crops and the climate.  For example, rice requires more water than cotton.  Wheat grown in a warm climate needs more water than wheat grown in a cool climate.

The original purpose was to determine which erosion control product would work best in a furrow irrigation system.  The results of this experiment are that straw worked the best in slowing the erosion at both an 8-degree incline and at a 16-degree incline.

Graphs

My hypothesis is accepted because I hypothesized that the straw would work the best to prevent soil erosion in a furrow irrigation system.  A question that was raised when the experiment was conducted is that I wonder if other types of dried vegetation such as grass clippings, leaves, or weeds would work as well as straw to prevent soil erosion.  If I were to do this experiment again I would conduct more trials at different inclines to see if the soil erosion control products would work the same.  I would also use different type of soil, such as clay or sand.

"Irrigation." The International Encyclopedia of Science and Technology. 1999.

"Soil Conservation." McGraw-Hill Concise Encyclopedia of Science and Technology 4th Edition. Ed: Sybil Parker. 1998.

Fangmeier, Delmar D. "Irrigation." The World Book Encyclopedia. 1999.

Hirschfeld, Sue Ellen. "Earth: Erosion." The World Book Encyclopedia . 1999.

"Irrigation." The International Encyclopedia of Science and Technology. 1999.

Laflen, John M. "Erosion." The World Book Encyclopedia. 1999.