Generally Accepted Agricultural and Management Practices for Irrigation Water Use

1. Generally Accepted Agricultural and Management Practicesfor Irrigation Water Use Note to Presenters: Handout material for this presentation is “ Irrigation Water Use GAAMP” Available from MDA at http://www.michigan.gov/mda search for Irrigation GAAMPs MSU Extension Educators, Dr. Tom Fernadas, Bruce MacKellar, Steve Miller, Lyndon Kelley other Irrigation GAAMPs taskforce member maybe able to answer questions or present this material if needed.

2. Generally Accepted Agricultural and Management Practicesfor Irrigation Water Use“2007 updates” December 2007

3. What do we use the Irrigation Water Use GAAMPs for ? • Sets the standard Right to Farm complaints in the irrigation water use area will be evaluated against. • Right to Farm Act is Nuisance law suit protecting for agriculture. • Farmer are granted this protection if they are following generally accepted agricultural management practices.

4. What do we use the Irrigation Water Use GAAMPs for ? • Irrigation water use GAAMPs are sited as a qualifier for agricultural related large volume water use complaints. • Irrigation water use GAAMPs are the core of the irrigation water use plan that large volume water user file as part of the water use reporting system.

5. Generally Accepted Agricultural and Management Practicesfor Irrigation Water Use • Draft up for public comment through December 17th. (MDA Website, GAAMPs) • Written comments can be mailed or filed electronically through the MDA website. • Public comment meeting 1:00 December 17th at State Library

6. Irrigation GAAMP Task Force • Climatology Jeff Andresen • Environmental Interests • Farm Bureau Scott Piggott • Vegetable Industry Dave Smith • Great Lakes and WRC Fred Henningsen • MSU Extension Lyndon Kelley • Groundwater Hydrology David Lusch • MDA Mike Gregg • MDEQ Ron Van Til

7. Irrigation GAAMP Task Force • Nursery Interests Dr. Tom Fernadas • MSU Greenhouse AOE Tom Dudek • MSU Nursery AOE Dean Kropcoft • NRCS John Barclay • NRCS Steve Davis • Potato Industry Comm. Ben Kudwa • SW MI Seed Growers Ben Russell • USGS Jim Nicholas • MSU Vegetable AOE Ron Goldy • MSU Field Crops AOE Bruce MacKellar • MSU Agriculture Eng. Steve Miller

8. GAAMP Document in Three Sections • I. Introduction • Stewardship • DO NOT ESTABLISH LEGAL CRITERIA to resolve water use conflicts • DO NOT CONFER PRIORITY RIGHTS to water use • II. The 25 GAAMPS • System Management................................................ 2 • Record Keeping........................................................ 4 • Irrigation Scheduling................................................ 5 • Application Practices ............................................... 9 • Additional Reasons to Irrigate............................. 10 • Practical Considerations......................................... 12

9. GAAMP Document in Three Sections • III Background – Information and education • Irrigation in Michigan • Relation to other GAAMPs • Michigan Water Law related to Irrigation • Planning and Preparation for Irrigation

10. Introduction – Stewardship • Stewardship of the water resource quantity • Irrigators are to use water as efficiently as possible while providing the crop/landscape water needs • Avoid over irrigation • Stewardship of the water quality • Irrigation without deep percolation or runoff • Stewardship of the soil • Use management practices to maintain the soil infiltration characteristics and increase organic matter content to increase water holding capacity • Stewardship of the crop – sustain plant development • Stewardship of the Agricultural sector of the economy

11. Management GAAMPs • 1. Determine water applications accurately • Totalizing flow meter and known area of coverage • Calibrated sprinkler package and system speed • Numerous rain gauges in the field • 2. Monitor pumping plant efficiency – Moved to recommendations • Maintain the desired flow and pressure • Monitor system pressure • System flow is uniquely related to system pressure

12. Management GAAMPs (con”t) • 3. Evaluate the irrigation system uniformity • To know what it is applying and how uniformly • Periodically – every few (5-8) years or when something is changed • Evaluate according to a standard • NRCS handbook – Pivot run with catch cans spaced 15-30 ft. • ASAE standards (436.1) – Pivot run with cans spaced 10 – 17 ft (3-5 m)

13. Irrigation System Uniformity -Options • Michigan Groundwater Stewardship Technicians • MSU Extension trainings for producers • Private consultants

14. Sprinkler overlap with end gun Tower 1 Tower 3 Tower 5 Tower 7 Tower 8 http://web1.msue.msu.edu/stjoseph/anr/anr.htm

15. Management GAAMPs (con’t) • 4. Maintain the irrigation system in good condition • Mostly means have a detailed look at the machine • Sprinklers rotating properly, nozzles not worn or blown out • Proper pressures at the nozzles • Pipes free from leaks • Inspect regularly and document inspections • Beginning of irrigation season • During the season

16. Management GAAMPs (con”t) • 5. Operate to minimize drift and off target applications • Don’t water the roads or the neighbor’s house • Avoid operation in high winds where possible • Be sure stops and auto-switches are working properly • 6. Ensure that irrigation system output does not greatly exceed the infiltration rate of the soil or substrate. • Goal is to avoid runoff or run-on • An initial design issue • Runoff can sometimes be managed by reducing application amount or changes tillage practices • In nursery systems, manage runoff by recycling or proper disposal

18. Management GAAMPs (con”t) • 7. Provide noise control for engine driven pumping units. • Internal Combustion engines running pumping plants or generators • Mufflers • Sound baffles • Carefully chosen location

19. Provide noise control for engine driven pumping units. Noise control providedwhen needed. 2.3 Irrigation Management Practices

20. Record Keeping • 8. Records should conform to the requirements of the Michigan Water Use Reporting laws and regulations. • 9. Keep records on all system inspections and repairs that influence uniformity and leaks. • 10. Maintain records of regularly calibrated fertigation and chemigation equipment, if used. • 11. Keep records of the results each time the irrigation system uniformity is evaluated.

21. Irrigation Scheduling • Scheduling is determining when to irrigate and how much water to apply • Everyone schedules!! • Scientific methods involve treating the soil as a reservoir for plant water and maintaining the reservoir within an acceptable range for plant use

22. Irrigation Scheduling • 12. Avoid applying irrigation water in excess of the quantity of water needed to replace the soil/substrate moisture deficit.

23. Irrigation Scheduling • 13. Know the available water for each unit scheduled. • AWC is the difference between the soil water content at the drained upper limit (“Field Capacity”) and the content at which plants permanently wilt. • Data available from NRCS • Usual range is .07 -- .15 inches of water per inch of soil or 0.8 – 1.8 inches per foot.

24. Irrigation Scheduling • 14. Know the depth of rooting for each crop irrigated • 15. Use container capacity in scheduling irrigation for container grown crops. • Typical container substrate capacity ranges 45 – 60% by volume • 16. Know the allowable depletion of each crop and stage of growth • The allowable water depletion is less than the total available water – usually 40 – 60% of total, depending on the crop and stage of growth • Container depletion may be 25 – 35% of container volume

25. Irrigation Scheduling • 17. Measure, estimate, or use published evapotranspiration data and crop co-efficients (when available) to determine crop water use. For some crops, you may wish to consult an irrigation specialist for assistance. • Measure soil moisture status • Estimate using weather data (MAWN) • Use published information (off the web) • Even with good estimates, field checks are needed • 18. Measure rainfall in the field

26. Irrigation Scheduling Checkbook Method

27. Other Reasons to Irrigate • 19. Other needs for irrigation • Frost protection • Seed germination • Herbicide activation • Reduce disease • Establishment of post-harvest cover crops • Control of wind erosion in small and emerging crops • Post-harvest maintenance of ornamentals • Provision of proper conditions for harvesting (root) crops • Chemigation • Crop cooling in special cases with fruit crops • Establishment and maintenance of a water table for sub-irrigation

28. Application Practices(to avoid leaching) • 20. Chooseirrigation application amounts that will avoidsurface runoff under sprinkler irrigation. Depends on soil type and system application rate • Runoff and run-on can cause nonuniform application and leaching • In container culture, manage runoff that may occur • 21. Assure that sprinkler application rates are below the soil infiltration rate in order to prevent runoff and accumulation of water in lower areas, which may result in excess infiltration and leaching.

29. Preventing Irrigation Runoff(comparing irrigation application rate to soil infiltration rate and amount applied)

30. Application Practices • 22. When irrigation is used, split application of nitrogen fertilizer or use controlled release fertilizers. • Goal is to avoid excess nitrogen leaching • Rainfall right after irrigation can cause over filling of the soil water holding capacity and deep percolation which may leach excess nitrogen in the profile • 23. Incorporate appropriate backflow-prevention safety devices if a chemigation system is used.

31. Are appropriate backflow prevention devices in place and properly maintained if fertigation or chemigation is used? Backflow prevention safety devices are usedand properly maintained if fertigation or chemigation are used. 2.9 Irrigation Management Practices

32. Background Section • This section is information and education, not accepted agricultural and management practices • Divisions within the section • Irrigation in Michigan • Relation to other GAAMPs • Michigan Water Law related to Irrigation • Planning and Preparation for Irrigation

33. Irrigation in Michigan • Importance of Irrigation nationally and in Michigan – used with higher value crops • Goal of irrigation is to minimize moisture stress and maximize crop quality while minimizing the effect on the environment and water resources • Michigan is water rich, but is the driest state east of the Mississippi during July and August • Water is available to replenish aquifers and supply rivers and lakes during other parts of the year • The GAAMPs do not establish legal criteria to resolve water use conflicts or confer priority rights to water use

34. Irrigation in Michigan (con’t) • Irrigation replaces water used by plants • Plants use water primarily for cooling • Certain high value crops would not be grown in Michigan without irrigation • High value crops provide added income in communities • Access to irrigation water is key to high value crop production and the ripple effect on the economy

35. Relation to Other GAAMPS • Manure Management GAAMPs recognize irrigation as a method of land application • Nutrient Management GAAMPs recommends • Don’t irrigate to completely fill the soil reservoir • Use multiple applications of N-fertilizer • Recognizes fertigation offers special advantages • Special care when irrigating container grown plants to avoid leaching and runoff • Pesticide Utilization GAAMPs • Recognizes chemigation as an accepted practice • Recommends safety measures including backflow prevention devices

36. Water Law and Ag Water Use • Points out that P.A.83 of 1981 (the Right to Farm Act) provides farmers who follow GAAMPs with limited protection from nuisance suites. • Adherence to the Water Use GAAMPs does not provide a complete barrier against lawsuits. • Recommends that water users who are concerned about their rights, consult MSUE, NRCS, MDA, MDEQ, or an attorney versed in water law

37. Planning and Preparation for Irrigation • Water Supply • Plan to keep up with a water use of 0.25 in/day (approximately 5 gpm per acre) • Some streams, lakes and wetlands may be sensitive to large withdrawals • Groundwater removed for irrigation may reduce flow to these surface water bodies

38. Planning and Preparation for Irrigation • Aquifer monitoring • Seek information before drilling to determine adequacy of the source • In areas where there is known potential for impacting other wells, consider using monitoring wells • Drill and pump a test well before installing a production well • Monitor levels in your irrigation well • To determine the effect on the aquifer • To determine need for maintenance • Irrigation wells should be set up for monitoring the water level • Recommend three measurements per year • Before the irrigation season • In mid-season, both static and dynamic levels • After the end of the season • Keep records on these measurements

39. Questions and Discussion?