Irrigation Systems

1. Irrigation Systems

2. Rainwater Most farmers in the world depend solely on seasonal rains to water their crops

3. Rainwater • Advantages: • No labor required • Free • No technology or equipment required • Disadvantages: • Not suitable for all crops in all climates • A dry year can severely lessen yields or loose an entire crop • Bad droughts and lead to little or no income and/or famine

4. Hand Watering • Watering individual plants by hand • Usually involved hauling buckets, watering cans or a hose

5. Hand Watering • Advantages: • Minimal and low-tech equipment needed • Very cheap • Water applied directly to plants • Disadvantages: • Labor intensive • Inefficient for watering a large amount of land • Slow

6. Surface or Flood Irrigation • Water moves over and across the land by simple gravity flow • This has been the most common method of irrigating agricultural land

7. Surface or Flood Irrigation • Advantages: • Relatively small investment on low-tech equipment • Simple to understand • Disadvantages: • Labor intensive • High maintenance • Can lead to water-logging and soil salinity if there is not adequate drainage • Won’t work well on uneven surfaces

8. Sprinkler • Water is piped in and distributed by overhead high-pressure sprinklers or guns from a central location in the field or from sprinklers on moving platforms

9. Sprinkler • Advantages: • Even distribution of water • Unaffected by uneven land surfaces • Ability to apply fertilizers and herbicides through the system • Less labor required • Disadvantages: • Can cause crusting of soil surface • Strongly affected by windy conditions • High maintenance requirements • Initial investments can be high • Wet foliage is susceptible to disease • Up t0 50% of water can be lost to evaporation before plants absorb it

10. Center Pivot • Water is distributed by a system of sprinklers that move on wheeled towers in a circular pattern • This system is common in flat areas of the United States

11. Center Pivot • Advantages: • Even distribution of water • Ability to apply fertilizers and herbicides through the system • Covers a large area with less sprinkler heads • Low labor • Disadvantages: • Can cause crusting of soil surface and soil erosion • Strongly affected by windy conditions • High maintenance requirements • Expensive to setup and fix • Technical knowledge of system required

12. Lateral Move Irrigation • Water is distributed from a main hose through a series of pipes, each with a wheel and a set of sprinklers • After an area has been sufficiently watered the system is moved across the field either by hand mechanically

13. Lateral Move Irrigation • Advantages: • Similar to center pivot irrigation • Lower input costs than center pivot • Disadvantages: • Also similar to center pivot irrigation • Higher labor requirements than center pivot

14. Drip Irrigation • also known as trickle irrigation • Water is delivered near the plants roots, drop by drop

15. Drip Irrigation • Advantages: • Ability to irrigate irregularly shaped fields • Minimal soil erosion • Highly efficient and conserves water • Reduced risk of disease from wet foliage • Waters only root zone of plants • Less soil crusting and weeds • Less water lost to evaporation

16. Drip Irrigation • Disadvantages: • Very expensive investment • Initial setup is labor and time intensive • Post-season cleanup required • Uses lots of plastic • Can result in seed germination problems • Requires sediment-free water

17. Drip Irrigation • Used since ancient times when buried clay pots were filled with water, which would gradually seep into the grass • Modern drip irrigation began its development in Afghanistan in 1886 with clay pipes • The advent of modern plastic allowed for vast improvements in tubing • Plastic emitters and modern drip irrigation was developed in Israel by Simcha Blass

18. Drip Irrigation • Drip irrigation is a sustainable solution in many, BUT not all agricultural applications. • Ideal for watering landscapes, vegetable crops, orchards and vineyards. • Not ideal for large field crop production such as alfalfa or soybeans. • Greatly reduces the overall amount of water used by supplying water only where the plants can use it

19. What is the Best? • Irrigation method used depends on : • Crop being grown • Topography • Region • Climate • Water availability • Available money and labor

20. Sustainable Water Practices

21. Don’t Lose to Evaporation • When crops are irrigated by overhead sprinklers nearly 50% of the water is lost to evaporation before it is absorbed by the plants. • Even when watered with drip irrigation water evaporates faster than it is absorbed. • Evaporation is caused by the sun hitting and heating water molecules. • Watering plants in the early mornings or late afternoon/evening when the sun is not shining will greatly reduce water lost to evaporation

22. Mulch Magic • Mulch is a protective cover placed over soil to help retain moisture…as well as reduce erosion and suppress weeds. • Mulching provides a more natural environment for plants by mimicking leaves that pile up on the forest floor. • Materials: • Organic mulches include yard clippings, leaves, straw, shredded tree bark, sawdust and compost • Synthetic mulches such as rubber from recycled tires and plastic sheeting

23. Mulch Magic

24. Swales • A Swale is a ditch on the contour of a hillside. • It does not direct water, but rather holds it and allows it to gradually infiltrate the soil down-slope of it. Soil and water run-off are caught in the swale, which becomes a fertile area. Gradual infiltration of water and nutrients in the swale slowly improve soil structure down-slope.

25. Swales • How a swale works: • Swale Plume • Example of what can be accomplished with swales: • Greening the Desert