Exam 1 Study: Worldwide Irrigation Systems

Question 1

Irrigation

Answer 1

The controlled application of
water for agricultural purposes
through manmade systems to
supply water requirements not
satisfied by rainfall

Question 2

What do we irrigate?

Answer 2

• Sports fields
• Agriculture crops
• Lawns
• Gardens

Question 3

Why do we irrigate crops?

Answer 3

• Cause I like to eat!!!
• Increase production
• Speed up production
• Grow food in dry areas
• Mitigate drought

Question 4

How much do we irrigate?

Answer 4

1. Irrigation is measured in depth (inches or mm)
2. Each plant has a water requirement
3. • Climate has an impact
   • Sun
   • Heat
   • Humidity
   • Rainfall
   • Wind
4. Evapotranspiration

Question 5

Plant types and their water use

Answer 5

Most native and adapted plants, cacti, succulents, yuccas, Buffalo grass. LOW water usage (0.3 plant factor)

Non-native ornamental perennials, most non-native bushes and shrubs. MEDIUM water usage (0.5 plant factor)

Annual ornamental plants, tropical plants, ferns, vegetables and fruits. HIGH water usage (0.8 water factor)

Turfgrass such as St. Augustine and Bermuda use a lot of water. (0.6 plant factor)

Question 6

Average Crop Water Requirements

Answer 6

• Corn ~ 26 inches
• Cotton ~ 27 inches
• Sorghum ~ 22 inches
• Small Grains ~ 30 inches
• Vegetables ~ 22 inches
• Fruit Trees ~ 36 inches

Question 7

Acre-inch is ______ gallons of water

Answer 7

27,541

Question 8

Average Landscape Plant Water Requirements

Answer 8

• Sports Turf Grass ~ 34 inches
• Residential Home Lawn ~ 25 inches
• Flower/Bedding Areas ~ 21 inches

Question 9

Resources Required to Irrigate

Answer 9

• Water
• Pump (pressure & flow)
• Piping
• Emitter(s)

Question 10

Agricultural Irrigation
Methods

Answer 10

Flood irrigation (ac-ft)
* Furrow
* Whole field
*Sprinkler irrigation (GPM)
* Center pivot (traditional)
* Large ag sprinklers
*Drip irrigation (GPH)
* Surface
* Subsurface

Question 11

Flood Irrigation

Answer 11

• Most common worldwide
• Known to be least efficient
• High water losses
• High flow rates
• Low water pressure
• Ample water supply
• Inexpensive water supply
• Flowrate – acre-feet (ac-ft)

Question 12

Sprinkler Irrigation

Answer 12

• Single large nozzle
• Multiple small nozzles
• High pressure
• High to medium flowrates
• Moderate water use
• Moderate losses
• Flowrate – gallons per minute (GPM)

Question 13

Drip Irrigation

Answer 13

• Surface drip
• Subsurface drip
• Low pressure
• Low flow rate
• Emitter: GPHs
• Filtration required
• Highest efficiency
• Flowrate – gallons per hour (GPH)