Now that spring has sprung, one of the most powerful tools for maximizing irrigated yield is uniform application of irrigation water.  Testing uniformity every few years is a low cost way to make sure that your water is going where you want it. On a pivot with 15 foot nozzle spacing, one bad nozzle 1000 feet from the center can influence the yield on over 2 acres. That one bad nozzle (that costs about $5 to replace) could cost you over $600 in lost yield.
Below is a quick tutorial on irrigation uniformity testing.