Reading your bucket test results and deciding what to fix

A bucket test gives you numbers, but the real value is in what they tell you to do next. Here's how to read your results.

Start with application depth

Compare the average depth you measured with what you expected at that speed or run time. If you're applying noticeably less than you thought, check the pump, pressure and flow. If you're applying more, your irrigation schedule may be putting on more water than you planned.

Then look at uniformity

Your DU or CU tells you how evenly the water is spread. A high figure means the system is in good shape. A falling figure across seasons means wear is setting in. A low figure means it's worth finding the cause.

Read the pattern

The pattern along your bucket line often points straight at the problem:

• One low bucket, or a couple together: often a blocked, missing or damaged nozzle or sprinkler at that spot.
• One high bucket: a wrong or worn nozzle, a leak, or a dripping boot.
• A whole section low or high: the wrong nozzle package for that section, or a pressure problem.
• Low readings near the end: low pressure at the end of the machine, or an end gun problem.
• Erratic readings everywhere: possibly wind on the day, or worn sprinklers throughout. If it was windy, retest before you spend money.

Fix in the right order

1. Fix the obvious faults first, such as blocked nozzles, leaks and damaged sprinklers. They're cheap and quick.
2. Check pressure along the machine against the nozzle chart.
3. If those don't solve it, get the nozzle package checked against the current pump and pressure.
4. Retest to confirm the fix worked.

When to call in help

If the pattern doesn't make sense, or basic fixes don't improve it, call in an irrigation technician. Take your test results with you, because they'll save time on the diagnosis.

Try it: The free Uniform Ag calculator shows your readings along the line, so the pattern is easy to see.