T9-1 Soil Science & Management, 4E

Chapter 9

Drainage and Irrigation

T9-2 Soil Science & Management, 4E

Objectives• Define drainage and explain its

importance• Explain the difference between wetlands

and wet soils• Identify methods of artificial drainage• Identify methods of irrigation• Decide when and how much to irrigate• Name water quality problems for

irrigation

T9-3 Soil Science & Management, 4E

Terms to Know• Border-strip irrigation• Capillary fringe• Center-pivot irrigation• Drainage• Drip irrigation• Furrow irrigation• Hand-move irrigation• Hydric soil• Hydrology• Leaching requirement• Perched water tables• Saline soil

• Seeps• Solid-set irrigation• Soluble salts• Subirrigation• Subsurface drainage• Surface drainage• Surface irrigation• Traveling-gun irrigation• Wetlands• Wheel-move irrigation

T9-4 Soil Science & Management, 4E

The Importance of Drainage• Effects of poor drainage

Figure 9-1

T9-5 Soil Science & Management, 4E

Wetland and Wet Soils

• Wetlands

– Water control

– Water quality

– Wildlife habitat

– Recreation and education

T9-6 Soil Science & Management, 4E

• Wet soils

Wetland and Wet Soils

T9-7 Soil Science & Management, 4E

Artificial Drainage

• Surface drainage

• Subsurface drainage

T9-8 Soil Science & Management, 4E

Irrigation Systems

Figure 9-7

T9-9 Soil Science & Management, 4E

Irrigation Systems

Figure 9-8

T9-10 Soil Science & Management, 4E

Irrigation Systems

• Subsurface irrigation

Figure 9-9

T9-11 Soil Science & Management, 4E

Irrigation Systems

• Surface irrigation– Border-strip irrigation– Furrow irrigation

T9-12 Soil Science & Management, 4E

Irrigation Systems

• Sprinkler irrigation– Hand-move irrigation– Solid-set irrigation

Figure 9-13

T9-13 Soil Science & Management, 4E

Irrigation Systems

• Traveling-gun irrigation

• Center-pivot irrigation

T9-14 Soil Science & Management, 4E

Irrigation Systems• Wheel-move irrigation• Microirrigation

– Drip irrigation– Microspray irrigation

Figure 9-18

T9-15 Soil Science & Management, 4E

Using Irrigation

• Deciding when to irrigate

Figure 9-20

T9-16 Soil Science & Management, 4E

Using Irrigation

• How much to water

Figure 9-21

T9-17 Soil Science & Management, 4E

Using Irrigation

• Saving water

Figure 9-22

T9-18 Soil Science & Management, 4E

Water Quality

• Suspended solids

• Boron

• Soluble salts Figure 9-23

T9-19 Soil Science & Management, 4E

Water Quality

Figure 9-24

T9-20 Soil Science & Management, 4E

Summary

• Advantages to artificial drainage• Poorly drained O2 deficient• Irrigation supplies water• Avoid water stress• Watch water quality• Use water efficiently