Soil incorporation is sometimes not possible due to cropping or soil conditions. Research has shown that aerating stored liquid manure for as little as four hours before spreading removes most of the odorous sulfur compounds. Field-spreading can then proceed under conditions that normally would cause an odor nuisance. The operator must realize that more odor will be released when aerating the manure storage, so aerating must be done when odors released will cause minimal nuisance. Select a day when the wind is blowing in a direction other than toward close neighbors.
Many operators use irrigation equipment to spread liquid manure on cropland.
Aerosol drift is a major concern because odors are transported with the aerosol. Lower trajectory nozzles reduce aerosol drift. A buffer zone is recommended in which no irrigating is done. A minimum width for buffer zones is 50 feet from roads and 200 feet from residences when the wind is blowing away from them. If the wind is blowing toward these areas, a much larger bufferzone is needed.