Sustainable forage production depends on applying the right amount of water at the right time to meet crop demand while protecting soil structure and water quality. Oregon State University notes that over-irrigation can lead to leaching losses of nutrients, costing funds and potentially degrading underlying aquifers.
For alfalfa and grass hay, the “best” traveling irrigation system is the one that matches crop water use, soil intake/storage, and your available pressure/flow and can operate on your field layout without creating harvest or traffic problems.
Start with crop water use and the cutting cycle (alfalfa)
Kansas State University Extension reports:
- A normal mid-season alfalfa water-use rate of 0.35 inch/day (about 1 inch every 3 days).
- Water use drops when leaf area is removed at harvest, then increases with regrowth, generally reaching full use in a 10–12 day period.
- Peak rates of 0.5 inch/day occur but typically don’t last more than a day or two.
- Soil-water storage + irrigation system capacity must equal long-term use rates to maintain production.
Implication for system choice: your traveling irrigator setup must be able to “keep up” during high-use periods and recover quickly after cutting.
Protect soil structure and hay quality by timing irrigation around harvest
K-State also notes that:
- A dry surface is preferred for harvest traffic; the surface should be allowed to dry and stabilize before harvest.
- Alfalfa is sensitive to excess soil water; surface water should not stand more than 24 hours in hot weather or 48 hours in cooler temperatures because excess moisture causes root and crown diseases.
Implication for system choice: select a traveling irrigation approach you can schedule so you’re not forcing harvest operations onto wet ground.
Grass hay and pasture: irrigate to soil intake, storage, and ET
Oregon State University’s Small Farms Program advises:
- For production, follow a plan based on infiltration rate, soil water-holding capacity, and moisture loss to evapotranspiration (ET).
- Using soil moisture monitoring can help determine when to irrigate, whether irrigations are sufficiently spaced, and whether the proper amount is applied each time.
Implication for system choice: your traveling system should support controlled, repeatable applications that can be scheduled from soil/ET information.
Match the system to your field and water supply (no system is universally “best”)
A UC Davis proceeding comparing flood and pivot irrigation for alfalfa states that both systems have strengths and weaknesses and that neither system is superior in all circumstances.
For sprinkler-based systems, North Dakota State University notes that sprinkler packages can operate across a wide range, with examples at 25–80 psi at the pivot point illustrating how variable on-farm pressure regimes can be.
Implication for system choice: start with what your water source can deliver (pressure/flow at the hookup) and select a traveling irrigator designed to run in that operation.
Traveling irrigation for forage with Vaughan Irrigators USA (published specs and setup methods)
Vaughan Irrigators USA publishes operating specifications and setup guidance for low-pressure traveling irrigators intended for field irrigation (the manual notes use “to irrigate fields (up to 40 acres)”). (VCI-MK1 & VCI-MK2 User Manual, 2025, p. 4)
VCI-MK1 and VCI-MK2 Operating Range
| Model | Operating pressure (psi) | Flow rate (gpm) | Throw distance (ft) |
|---|---|---|---|
| VCI-MK1 | 30–90 | 47–128 | 135 |
| VCI-MK2 | 30–90 | 47–128 | 160 |
(VCI-MK1 & VCI-MK2 User Manual, 2025, p. 4)
The manual states the system is compatible with low-pressure operation and can be run using a “simple firefighting pump,” avoiding the need for high-pressure pumps and piping. (VCI-MK1 & VCI-MK2 User Manual, 2025, p. 4)
The manual also reports that farmers have reported approximately 70% less water usage compared to flood irrigation(reported experience, not a guarantee). (VCI-MK1 & VCI-MK2 User Manual, 2025, p. 4)
Controlling application depth: nozzle + travel speed (field-practical adjustment)
The Vaughan user manual includes “Performance Indicator” tables (nozzle/flow/pressure/spray width/area covered/application inches per hour) and provides a worked travel-speed example:
- At 58 GPM with 1/2" nozzles, placing the clip in the second hole (two teeth) typically results in an irrigation cycle of 6 hours and applies 0.61 inches of water. (VCI-MK1 & VCI-MK2 User Manual, 2025, p. 37)
For sustainable forage production, this matters because it supports repeatable applications that can be aligned to soil moisture and ET planning (Section 3).
Hose layout and hydrant placement: reduce kinks and excess hose length
Vaughan’s manual states:
- Use heavy-duty, abrasion-resistant lay-flat irrigation hose; lay-flat is preferred over rigid poly pipe that is prone to kinking, which can restrict flow and require cutting/rejoining. (VCI-MK1 & VCI-MK2 User Manual, 2025, p. 38)
- The ideal supply hydrant location is the center of the irrigator run, which minimizes hose length and supports efficient water delivery. (VCI-MK1 & VCI-MK2 User Manual, 2025, p. 38)
For sustainable systems, minimizing kinks and unnecessary hose length supports consistent delivery and reduces downtime (which can drive over-application “catch-up” behavior).
Curved field edges and obstacles: guiding posts for controlled turns
Vaughan’s “Guiding Post” instructions state:
- The system allows turns up to 10 degrees at a time, and multiple 10-degree turns can be used in a single run for gradual curves. (How to Use a Guiding Post for Curved Paths, p. 1)
- Rule for cable routing: “Cable on the left for a right turn; cable on the right for a left turn.” (How to Use a Guiding Post for Curved Paths, p. 2)
This supports irrigating around field features without re-plumbing or reshaping the field.
If you’re feeding a traveling irrigator with a portable pump: priming and suction practices
The included NorthStar pump manual states:
- Attach a suction strainer and keep it clean; suspend it or keep it from sediment if possible. (NorthStar Water Pump Manual, p. 13)
- Place the pump as near the liquid surface as possible; keep hoses as straight as possible and avoid sharp bends. (NorthStar Water Pump Manual, p. 13)
- Do not run the pump dry; fill the pump body with water before starting and prime via the priming port. (NorthStar Water Pump Manual, p. 14)
Decision checklist (sustainable forage focus)
Crop demand and timing
For alfalfa, verify capacity against 0.35 in/day normal mid-season and rapid regrowth to full use in 10–12 days after cutting.
Soil and water quality
Build irrigation decisions from soil infiltration, water-holding capacity, and ET, and avoid over-irrigation that can drive nutrient leaching.
Water supply at the hookup
Confirm pressure/flow available; compare to the traveling irrigator’s published operating range (e.g., Vaughan VCI-MK1/MK2 30–90 PSI, 47–128 GPM). (VCI-MK1 & VCI-MK2 User Manual, 2025, p. 4)
Application control
Use published nozzle/speed guidance (e.g., Vaughan example 0.61 inches at a stated setup) to align with soil moisture/ET planning. (VCI-MK1 & VCI-MK2 User Manual, 2025, p. 37)
Layout and field geometry
Minimize kinks and excess hose by using lay-flat hose and placing the hydrant at the center of the run; use guiding posts for controlled 10-degree turns when needed. (VCI-MK1 & VCI-MK2 User Manual, 2025, p. 38; Guiding Post Guide, p. 1–2)