Uniform application of the irrigation water is essential to ensure uniform chemical distribution over the field. Most sprinkler irrigation systems can be designed and operated to achieve good uniformity of water application. Of the above-mentioned sprinkler irrigation systems, center pivots and linears are probably best adapted to chemigation because their coefficient of uniformity compares favorably with other application methods. However, as with aircraft and ground sprayers, the CU of these sprinkler irrigation systems decreases with increased wind speed. Also, steep slopes and hilly terrain may require pressure regulators on the sprinkler heads and higher operating pressures to get satisfactory uniformity of w ter application.
Many advantages accrue to chemigation.
There also are disadvantages associated with chemigation. Chemical applications may have to take place when additional soil water is not required. Ground water pollution is a possibility. Chemical applications during windy conditions can result in serious non-uniformity, especially with solid set and periodic move sprinkler systems. Sprinkler drift losses may become excessive when wind speeds exceed 15 mph.