Tools for Irrigation StewardshipLyndon Kelley, MSU Extension Thanks to Dr. Steve Miller - MSU Ag EngineeringDr. Ted Loudon - MSU Ag EngineeringDr. Ron Goldy - MSU ExtensionDr. Jeff Andreasen – MSU Geography
Size , Scale and Make-up Michigan – 452,000 acres Indiana 313,000 acres 2002 Agricultural Census
Size , Scale and Make-up Indiana 313,000 acres Michigan – 452,000 acres Summarized from 2002 Agricultural Census 11 Counties = 73.8 % of total 11 Counties = 69.2 % of total
Size , Scale and Make-up Indiana / Michigan Similarities • Predominantly Sandy Loam soils Irrigated • Water availability – abundant to scarce • Heavy irrigation - St. Joseph River basin • Knox / Montcalm – geographic, Veg. outliers • Irrigated crops make-up – Corn (commercial, seed,)- soybeans, vegetables, alfalfa, ornamentals • Water Regulation – modified riparian rights Summarized from 2002 Agricultural Census
Size , Scale and Make-up Indiana / Michigan Differences • Indiana has a heavier emphasis on irrigated corn • Michigan has a heavier emphasis on irrigated vegetables • Indiana has a more mature and less complicated water use regulation system (registration, complaints, reporting) Summarized from 2002 Agricultural Census
Targeted Audience Related to Irrigation Producers • Field crop production • Vegetable production • Small fruit and tree fruit • Turf and ornamentals Contractors of irrigated crop • Seed corn production companies • Vegetable and fruit processor / contractors
Technical Irrigation Issues • Tools for Irrigation Stewardship – Getting the most out of the water we use • Helping producers to understand the water cycle for their farms. • Working with irrigation equipment suppliers to help the irrigation related industries move economically and environmentally forward.
Tools for Irrigation Stewardship • Irrigation System Uniformity • Preventing Irrigation Runoff (comparing irrigation application rate to soil infiltration rate) • Irrigation Scheduling • Backflow protection • Avoiding water use conflicts • Record keeping
Needed Irrigation 5.5” Normal rainfall 34.6 Crop need 15.6” total
Equip Groundwater Conservation Program An NRCS Program to support Irrigation System Evaluations and System Corrections
Equip Groundwater Conservation Program - Michigan • Qualifications • System must have been in place for at least 2 years • Must use irrigation scheduling (Computerized or Paper System) • System uniformity coefficient must be below 85% to enter, and above 85% to qualify for payments. • Need to have an irrigation conservation plan • Write up that describes system, water source, how the irrigation is applied,
EQIP Groundwater Conservation Program - Michigan • Compensation: • A one time payment of $50/acre. • A maximum of 160 acres per producer can be enrolled in this program. • Funds for this program are split between irrigation management and dairy plate water cooler 100% water recovery, total funds available somewhere between $380,000. • See you local NRCS office. • Deadline to signup for this program will be March 15, 2007 at the Montcalm County NRCS Office.
Conservation Security ProgramReward the best, Inspire the rest. • Trend in Agriculture Government program is away from Subsidy based, toward Environmental protection. • Contracts for 5 or 10 years and payments of 2-8$/ acre (or more) are expected. • Available in counties starting in a rotational basis. • Farm must first meet soil erosion and water quality concerns.
Conservation Security ProgramReward the best, Inspire the rest. Two years of prior practice record will be required. Irrigation scheduling. Irrigation system evaluation. Records: water use, scheduling decisions, system repairs, evaluation data & modifications.
Irrigation System Uniformity • An 1” application should be 1” everywhere in the irrigated field • 10% or less deviation from the average is ideal. • Over applied area will likely be over applied each • application • Under applied areas will likely be under applied each • application • A 30% deviation on a field in an 8” irrigation application year will have areas receiving as little as 5.6” and as great as 10.4” • Repair all visible system leaks and problems first.
Irrigation System Uniformity Basic system evaluation Collect enough uniform container to to place every 10 feet the length of the system or across the application pattern. Spread the container every ten feet from the center point to the outside edge of the application area. Run the machine at standard setting over the container. Measure and record the water volume caught by each container Note sample point varying greater than 50% of the average.
Irrigation System Uniformity -Options • Michigan Groundwater Stewardship Technicians • Irrigator trainings ( MSU Ext., MGSP, NRCS ) • Private consultants
Sprinkler overlap with end gun Tower 1 Tower 3 Tower 5 Tower 7 Tower 8 http://web1.msue.msu.edu/stjoseph/anr/anr.htm
Preventing Irrigation Runoff(comparing irrigation application rate to soil infiltration rate)
Preventing Irrigation Runoff(comparing irrigation application rate to soil infiltration rate) • Sprinkler package or nozzle selection along with pressure dictates water application rate . • Factors that increase runoff : • Small Wetted area or throw of sprinkler • Low Pressure • Larger applications volumes • Soil compaction • Heavy soils • Slope • Row hilling
Instructions for completing the Evaluating Potential Irrigation Runoff form : • Identify the areas of the irrigated field that has the lowest infiltration rates. (heavy soils, slopes, surface compaction). • Select a transit line in the wetted area just behind the machine that covers the identified lowest infiltration rates of the field identified above.
Instructions for completing the Evaluating Potential Irrigation Runoff form – continued • Pace or measure 50 feet between observations starting at the pivot point and progressing to the furthest reaches of the machine. • Record observations for each location; look at several (4-5 areas) representing the row contour and differences in row traffic of the location. Record any specific concerns that may affect the application (drips or leaks) or affect the soils ability to take in water (compaction, row contours) Key for Observation column A- no observed puddling, ponding or sheen between rows B- puddling, ponding or sheen between rows identified, but no observed runoff or flow of water C-observed runoff or flow of water
Irrigation SchedulingRight to Farm GAAMPs • Irrigation scheduling for each unit or field • Irrigation scheduling is the process of determining when it is necessary to irrigate and how much water to apply • Irrigation water is applied to replace the water used by the plant.
Irrigation Scheduling • Method to determine the appropriate amount of water to be applied to a crop at the correct time to achieve healthy plants and conserve water • Can measure soil moisture Or • estimate evapotranspiration (ET) using weather data Potential ET measured by weighing lysimeter
Determining irrigation requirements • The plant water requirement includes the water lost by evaporation into the atmosphere from the soil and soil surface • and by transpiration, which is the amount of water used by the plant. • The combination of these is evapotranspiration (ET).
Meteorologically, ET depends on… Evapotranspiration (ET) = fn (net radiation) + fn (temperature) + fn (wind speed) + fn (air humidity)
Primary Factors • Know available soil water for each unit • Known depth of rooting for each crop • Know allowable soil moisture depletion at each stage of plant growth • Use evapotranspiration data to estimate crop water use • Measure rainfall in each field • Use container capacity for nursery crops
Think of your soil as a bank Rainfall and irrigation water are deposit into the bank Plant water use is a removalfrom the bank
Think of your soil as a bank Soil type : Heavier soil can hold more water / foot of depth than light soils Water holding capacity: The soil (bank) can hold only a given volume of water before it allow it to pass lower down. Intake rate: Water applied faster than the soil intake rate is lost. Deletion: Plants may can pull out only 30 – 60% of the water Rooting depth: The plant can only get water to the depth of it’s roots. Water lost from the bottom of the profile can wash out (leach) water soluble nutrients and pesticides.
Irrigation Scheduling Checkbook Method –University of Minnesota • Items to Conduct Checkbook Irrigation Scheduling • Two or more rain gauges • Max-Min thermometer or access to local temperature reports • Soil probe or in field moisture sensors • Daily crop water use table or local ET hotline or website report • Soil water balance worksheets • Estimate of soil moisture holding capacity
Rain Gauges • Basic unit – 2 inch opening • Cost less than $10 • One rain gauge for each 40 acres. • Recording rain gauge cost $50 - $100
60” SW 1/4 Frasier 3.0 30” 50 1.5 2.23 2.06 1.89 1.69 1.49 2.07 1.90 Jun 21 Jun 22 Jun 23 Jun 24 Jun 25 Jun 26 75 75 85 75 75 75 .17 .17 .20 .20 .17 .17 -0- -0- -0- -0- -0- -0- 0.75
60” SW 1/4 Frasier 60” SW 1/4 Frasier 3.0 30” 3.0 30” 50 1.5 50 1.5 2.23 2.06 1.89 1.69 1.49 2.07 1.90 2.23 2.06 1.89 1.69 1.49 2.07 1.90 0.77 0.94 1.11 1.31 1.51 0.93 1.10 Jun 21 Jun 22 Jun 23 Jun 24 Jun 25 Jun 26 75 75 85 75 75 75 .17 .17 .20 .20 .17 .17 -0- -0- -0- -0- -0- -0- Jun 21 Jun 22 Jun 23 Jun 24 Jun 25 Jun 26 75 75 85 75 75 75 .17 .17 .20 .20 .17 .17 -0- -0- -0- -0- -0- -0- 0.75 0.75
Average Water Use for Christmas trees (estimated at 1 inch/week) in inches/day Estimate of daily ET at 1 inch per week Estimate
Table 9. Average water use for any other crops when at full canopy at different times of the season Source: Data estimates full potential of daily ET per week by Killen, and was placed in the above table by Wright in January 2002.
Field beans Corn Soys Potato Alfalfa Alfalfa Corn Field beans Soys From Minnesota Extension bulletin “Irrigation Scheduling”, assuming temperature 80-89
Estimates of ET • Net radiation • Max and min temperatures • Relative humidly • Wind Purdue Agronomy web site – MichIna Irrigation Scheduler: Est. From High / Low temp. & date www.agry.purdue.edu/irrigation/IrrDown.htm
Estimates of ET U of Wisconsin web site -Next/rad radar : http://www.soils.wisc.edu/wimnext/ • Net radiation • Max and min temperatures • Relative humidly • Wind Provides the maximum water removal for the day
Converting acre inches to gallonsfor trickle irrigation • Calculate the % of area covered by trees (% of area you intend to water / tree ) • One acre = 43,560 sq.ft. • One acre inch = 27,154 gallons Example: The large tree you are watering have a diameter of 6.5 ft. 6.5 ft. x 6.5 ft. = 42 sq.ft. roughly 1/1000 of an acre 26 to 27 gallon / tree (include uncontrolled grass or weed area that is watered in tree area)
Irrigation Scheduling Checkbook Challenges Errors will accumulate over time -Weekly ground truthing needed Rainfall variability is more than often considered Only "effective” rainfall and irrigation should be considered Only water entering root zone is "effective”
Methods to Estimate Soil Moisture • Feel an Appearance • Electrical resistance – electrodes on blocks in soil • Tensiometers – measures soil moisture tension • Other probes – Nuetron, TDR