Colorado Agriscience Curriculum Development
Section: Plant and Soil Science
Unit: Environmental Factors
Lesson Number: 6
Lesson Title: Managing Water – Irrigation
Agriculture Education Standards:
AS 11/12.2-8
AS 11/12.4-13
Colorado Science Standards:
Student Learning Objectives/Enablers:
As a result of this lesson, the student will…
1. learn how irrigation began.
2. learn what irrigation is.
3. learn how much water is used in irrigation practices
4. learn what type of irrigation methods are used
Time: Instruction time for this lesson: 50 minutes
Resources:
URL: http://ga.water.usgs.gov/edu/wuir.html
Tools, Equipment, and Supplies:
Key Terms: The following terms are presented in this lesson and appear in bold italics:
Irrigation Micro-Irrigation
Evaporation Flood Irrigation
Transpiration Trenches
Application Sprinkler Irrigation
Evaporation Root Zone
Arid Drip Irrigation
Hydrolic Cycle
Interest Approach:
Have students access this link test their knowledge about water.
http://interactive2.usgs.gov/learningweb/fun/trivia_water_1.htm
What are some of the physical and chemical properties of water?
http://ga.water.usgs.gov/edu/sc3.html
SUMMARY OF CONTENT AND TEACHING STRATEGIES
Objective 1: The student will learn what the term “irrigation” means.
Utilize PowerPoint to have students take down notes on the important information.
1) What is irrigation? Ask students this question before giving the term below.
Irrigation, by definition, means to supply (dry land) with water by means of ditches, pipes, or streams; water artificially.
Irrigation, by one form or another, has been used for centuries. The application of water to soil and crops by artificial methods, first recorded in China, 560 BC.
Objective 2: The student will learn how much water is used during irrigation methods.
Utilize PowerPoint to have students take down notes on the important information.
1) How much water is used in irrigation? Can anyone take a guess?
Ask the students this question before showing slide # 8 on the PowerPoint.
Irrigation withdrawals were an estimated 137,000 million gallons per day.
2) How many acres were irrigated with the 137,000 million gallons?
Ask the students this question before showing slide # 10 on the PowerPoint.
About 61,900,000 acres were irrigated in 2000.
Objective 3: The student will learn the types of irrigation methods used today.
Utilize PowerPoint to have students take down notes on the important information.
1) What are some methods of irrigation? Let’s list them on the board.
Ask the students this question before showing slide # 11 on the PowerPoint.
(Slide 11 on the PP) Flood or furrow irrigation is sometimes referred to as surface irrigation. This type of irrigation consists of releasing water over the surface of the land to flood the fields. Flood irrigation is the oldest form of irrigation, and can be used for any crop. Ideally, the land is slightly sloped, and level enough for the water to distribute evenly over the surface. The more level the land, the more efficient the flooding will be. Efficiency in irrigation is measured by how much of the water spreads to the root zone of the plant. If too much water is applied, the water can soak below the roots and be wasted. Conversely, if not enough water reaches the root zone, the plant's health can be diminished. Most of the inefficiencies in the flood irrigation systems come from evaporation loss and water soaking into the soil in canals, trenches and ditches. Of course, there is a wide range in efficiencies, and some high-tech, laser-leveled fields may achieve up to 99 percent efficiency!
(Slide 13 on the PP) Sprinkler irrigation systems utilize pipes and sprinkler heads to distribute water to the plants. Three common types of sprinkler systems are solid set, continuous move, and periodic move. Sprinkler irrigations systems are usually more efficient that flood irrigation systems. Of course, they are more susceptible to wind than flood systems are, and can have much lower efficiencies in windy conditions.
(Slide 14 on the PP) Drip or trickle irrigation is also called solid set or micro-irrigation. Solid set sprinklers are permanently set in the ground and cannot be moved around the field. Typically the agricultural applications include orchards, vineyards, and other perennial plans that are not plowed. The two most commonly used types of solid set systems in agricultural practices are impact sprinklers and drip or micro irrigation. Impact sprinkler heads are similar to residential or commercial sprinkler systems seen in homes or building grounds. Micro irrigation systems are newer, and because of their cost, are typically used only for high valued crops such as vineyards or nuts. They utilize rubber tubing and micro-sprayers or emitters to water efficiently - one emitter at each plant.
REVIEW/SUMMARY
Have students do a Hieroglyphics Moment on the types of irrigation methods that were presented.
Application
Extended Classroom Activity
Ask help from your advisory council to get names of farmers in your area that use the different irrigation methods presented. Get permission from those farmers to bring your students on a field trip to their farm. Ask the farmers if they will give your students a presentation and tour of the irrigation method they use.
SAE Activity
Have students in your class involved in Plant Science SAE’s give a presentation of the importance of irrigation to their project.
Evaluation Answers
1. Flood irrigation was the first method used in irrigation.
2. China was the country that irrigation methods were first recorded. It was recorded in 560 B.C.
3. Sprinkler irrigation is the method that is susceptible to wind.
4. Drip irrigation is the method used in vineyards.
5. Irrigation means to supply dry land with water by means of ditches, pipes, or streams; water artificially.
Name: ______
Date: ______
Methods of Irrigation Evaluation
Use complete sentences when writing your answers.
1) What method of irrigation uses trenches or ditches?
2) In what country was irrigation first recorded? In what year?
3) What method of irrigation is susceptible to wind?
4) What method of irrigation is used in vineyards?
5) Define irrigation.