1. Understanding Agronomy

2. Irrigation

3. Objectives  Describe the benefits of irrigation; Describe the benefits of irrigation;  Identify ways to determine the need for irrigation; Identify ways to determine the need for irrigation;  Explain methods of water application; Explain methods of water application;  Describe irrigation scheduling; and Describe irrigation scheduling;  Describe efficient use of water. Describe efficient use of water.

4. Benefits of Irrigating  What are some benefits of irrigating your lawn?  Green all summer  Healthy  Less weeds  What are the benefits of irrigating crops?  Grow to maturity  Healthy  Produce highest yield possible

5. Benefits  Irrigation also:  Provides water when it is not naturally available  Is a method to apply fertilizers  Can protect crops from frost  Reduces dust

6. Benefits  What can happen if a plant is deficient in water?  Poor growth  Stunted mature plants  Lower crop yields (less $$)  Death of plants  Stress; more susceptible to disease  Loss of aesthetics(looks)

7. Determining a need  Knowing when to irrigate is important in soil moisture balance  Waiting for signs of stress is probably too late  Irrigate before the wilting point  Wilting Point: plant cannot take in water as quickly as it is lost

8. Determining a need  Once a plant wilts damage has already been done to production  You should check soil moisture before irrigating

9. Determining a need  Lots of methods can be used to test soil moisture without stressing the plant  Ribbon test  We’ve done this  Ball test  Roll a ball in your hand – if it crumbles you need water  Moisture sensor  Single electronic probe that tests moisture content  Sap flow sensor  Usually for trees or shrubs

10. Determining a need  More methods  Tensiometer  Determines pull of soil particles  Permanently placed in soil  Can be damaged by extreme weather  Moisture meter  Uses two probes in the soil  Remote sensing  Usually done with satellites  Ground truthing  Verifies accuracy of remote sensing

11. Methods of Applying Water  What made the “Fertile Crescent” Fertile?  Irrigation  How did they do it?  What are some methods we use today?

12. Methods of Applying Water  Subsurface irrigation  Piping system that is underground  Saturates the soil below plants and through capillary action, water will rise to the root zone  Not common and can be expensive

13. Methods of Applying Water  Trickle/Drip irrigation  Very controlled amounts of water  Similar to subsurface but usually runs above ground

14. Methods of Applying Water  Surface irrigation  Border Strip Irrigation  Both are very similar  Best on level to slightly sloped ground  Canals and ditches are used to carry water to the field  Can be piped  Evaporation can cause large amounts of waste Covers entire field Covers sections of the field

15. Methods of Applying Water  Furrow irrigation  Similar to the flooding  Water runs down furrows in between rows of crops  Usually same delivery system as flood  Can be piped

16. Methods of Applying Water  Sprinkler Irrigation  Several types  Usually pump water through a system of pipes  Good on ground that is not level

17. Methods of Applying Water  Hand-Line sprinklers  Least expensive start-up  Very labor intensive

18. Methods of Applying Water  Solid Set  Same equipment as hand lines, but set in place and never moved  Much more equipment = higher cost

19. Methods of Applying Water  Wheel lines  Pipe mounted on wheels  The pipe plays the role of the axle  Entire line moves all at once  Less equipment than solid set, but less labor than hand lines

20. Methods of Applying Water  Traveling Gun  One large sprinkler head mounted on a cart that travels across the field  Can be affected greatly by wind

21. Methods of Applying Water  Center Pivot  Central pivot point that an elevated pipe on wheels rotates around  Lowest labor requirement  Sprinkler heads must be engineered to release more water on the outside of the circle and less on the inside

22. Methods of Applying Water  Linear systems  Same type of equipment as center pivot  Entire line moves in a line  No pivot point  The end tower carries a pump that draws water from a ditch that runs the length of the field

23. Irrigation Scheduling  Irrigation scheduling is providing the right amount of water at the right time  Scarce water supplies are used more efficiently through scheduling  How is irrigation scheduled?

24. Irrigation Scheduling  Water supplies are usually increased before peak need  Usually in the middle of the growing season  Most crops are not watered each day  Needs are calculated and then water is applied at a very specific period of time  Some specialty crops are irrigated daily  The method of irrigation helps determine this  Part of scheduling is acquiring an allocation and time with the local water management district

25. Using Water Efficiently  Why should we use water efficiently?  How does it benefit us?  It is valuable; using more than you need will cost you lots of money  Your crops will be more productive if they are watered properly

26. Using Water Efficiently  Some ideas to think about when irrigating  Use during cool parts of the day or night time  Use when wind is not blowing  Lots of water is lost through evaporation when it is hot or windy

27. Using Water Efficiently  Monitor moisture in the root zone  Saturating beyond the root zone can lead to leaching

28. Using Water Efficiently  Avoid leaky irrigation systems  Apply water uniformly  Do all areas of a field need the same amount?  Do all areas of your lawn need the same amount?  No

29. Using Water Efficiently  Use irrigation method best suited for your land  Avoid runoff  It can contain fertilizers, pesticides and sediment that can pollute surface and ground water