Menu

Time to Repair Leaky Gates/Gaskets and Eliminate a Set

Minimizing inefficiencies in gravity irrigation systems can save irrigators money and labor. Normal wear and tear associated with piecing together sections of irrigation pipe and opening and shutting gates can cause significant inefficiencies to irrigation over time.


Estimating Losses.
Flow meters provide a method for estimating the amount of water that leaks from gates and gaskets. While leaks are not losses from the field, they do reduce the amount of water delivered to the set being irrigated. A Tri-Basin Natural Resource District study in the early 1990s showed that losses can exceed 50%.

Often losses can be 20% to 30%, which is 5 to 6 gallons/minute per 30-foot length of pipe on most systems. A quarter mile length of pipe on a 1000 gallon/minute well would deliver only 750 gallons/minute to the set if the water loss is 25%.


Saving Water.
The impact of losing 250 gallons/minute is shown in Table 1. The example simplifies calculations by using average set size, although number of gates per set is generally variable. It also assumes potential flow rate to be equal at both ends of the line, although actual field results will be different. The example depends on which set of gates are open, system design, and relative elevation from one end to another.

Saving Labor.
Reducing leaks has added benefits that are not included in the suggested “added profit.” Labor is an obvious major savings associated with fewer sets per irrigation. A value was not assigned to labor so you can use your own numbers on eliminating two trips to the field and the time associated with setting gates and checking rows.


Improving Water Quality.
Another benefit can be improved ground water quality. Severe leakage can add a constant supply of water to one area for the duration of the irrigation. On silt-loam soils, one gallon per minute running down a row will only advance about 100 feet. If that loss were to occur uniformly along the pipeline, it would amount to about three acres along the pipe.

If leaks continued for three days at a rate of 250 gallons/minute, 40 acre-inches per irrigation would be applied to about three acres of cropland. Estimates suggest that 5 pounds of nitrate move with every inch of water that leaches below the root zone (Watts).

Continuous leaking has the potential to flush hundreds of pounds of nitrogen into the aquifer. Aside from contaminating the aquifer, it would take additional nitrogen to offset the loss, or acceptance of fewer bushels produced from those three acres.

Recommendations

  • Flag leaky gaskets and mark leaky gates during the year to ensure repairs can be made in the off-season.
  • Discard gaskets where flagged, as you pick up pipe at the end of the season. Some people carry gates with them and change damaged gates when they are found during the year. If that doesn’t work for you, mark your calendar to replace gates after harvest.

A little labor in the off-season can pay big dividends when the demands for labor are great during the summer.

Source: C. Dean Yonts and Andrew Christiansen, University of Nebraska-Lincoln

Recent News

Corn Silage Needs Adequate Moisture to Ferment
9/18/2020

Early season frost is challenging for corn silage producers, according to Karl Hoppe, Extension livestock systems specialist at NDSU’s Carrington Research Extension Center. Frost makes an abrupt end to the corn-growing season. This begins the dry-down period for the corn plants. “Good corn silage fermentation requires adequate moisture to reduce dry-matter loss and spoilage,” Hoppe […]

China-Corn Crop Impacted by Adverse Weather, as U.S. Wheat and Soybean Exports Increase
9/18/2020

Reuters writers Hallie Gu and Gavin Maguire reported on Wednesday that, “China’s corn crop is expected to fall by up to 10 million tonnes, or nearly 4%, from the latest government estimates after heavy wind and rains toppled crops in major production areas in the northeastern cornbelt, analysts said. “Expected production losses have pushed Chinese corn futures to […]

Surface Application of Manure to Newly Planted Wheat Fields
9/18/2020

Several livestock producers have inquired about applying liquid dairy or swine manure to newly planted wheat fields using a drag hose. The thought process is that the fields are firm (dry), there is very little rain in the nearby forecast, and the moisture in the manure could help with wheat germination and emergence. The manure […]

Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now