Some producers who use no-till practices face the dilemma of whether to use manure to enrich fields. “Best-management practices for manure applications call for incorporating it into the soil,” notes Dave Whitney, Kansas State University agronomist.
While surface application of manure without incorporation does raise some concerns, it does not mean that no-till producers can’t use manure. Actually, most application practices used on conventional-till fields still apply, says Whitney.
Major concerns for applying manure to no-till fields involve the potential for: manure to move off-site in surface-water runoff, odor problems and ammonium-nitrogen volatilization loss, says Dan Devlin, a Kansas State environmental quality specialist. Incorporation minimizes those potential problems.
To minimize runoff potential, manure should not be applied when that potential is greatest, says Devlin. This would include months when precipitation is high, as well as when ground is snow-covered or frozen. Application on steeply slopped land and near surface-water sources without vegetative filter strips should be avoided.
Little can be done to minimize ammonium-nitrogen volatilization from manure surface applications, says Whitney. Volatilization is slower in cool temperatures. However, without incorporation or precipitation to move ammonium into the soil within a couple of days, ammonium-nitrogen loss will be substantial regardless of the air temperature.
To manage objectionable odors from surface-applied manure, it should not be applied on fields near residences or when prevailing winds are blowing toward residences,” says Devlin. “There really are few other options.”
Also, you must follow the overall nutrient-management regulations for manure rates in the area.