Manure Contingency

A nutrient management lead with OMAFRA says manure application in winter should never be part of a management plan.

While manure applied to wheat crops or to forage crops can be an option during other times of the year, it should not not be done in winter on frozen soils.

Christine Brown writes that it should be part of a contingency plan.

Frequent rain and a late corn harvest is taxing manure storage capacities on many farms. And contingency plans are essential for manure that must be applied in less than ideal conditions.

A forage or wheat field can be an ideal site for contingency plan manure application, because compaction should not be an issue, and the soil cover would help prevent nutrient runoff and erosion.

Forage or wheat fields are ideal for those reasons. However, winter kill becomes a much greater risk, especially with application of liquid manure. Beside the common risks that include, compaction from wheel traffic, and crown damage; manure contains salts!

Salinization, the concentration of salt in the root zone, is not an issue in Ontario.

Ample precipitation and drainage leaches the salts through the soil profile.

However, when the soil is frozen, infiltration can’t occur.

Salts in manure can then turn deadly.

High sodium also has a negative effect on soil structure; making the soil more susceptible to crusting, and further decreasing the capacity for infiltration.

When contingency plan applications become necessary during the winter season, options include:

  • Late summer application to forage crops after the final cut or at the beginning of the critical harvest period
  • Temporary storage at a neighbouring storage that has extra capacity
  • Application to forage fields or cover crops that will be tilled or killed