As climate change and water quality concerns strengthen, there is increased public, government and media focus on the phosphorus levels in Ontario’s lakes and water courses. There are many urban and rural contributors, but agriculture is often an easy target because farmers’ nutrient management activities are highly visible.
That’s especially the case for hauling and applying manure.
We know manure plays an important role in soil health and crop production, but how and when it is applied can have significant impact on environmental stewardship. Winter application of manure, whether solid or liquid, should be avoided wherever possible – and here are four reasons why:
- Nutrient losses
Livestock manure is a valuable resource and when nutrients are washed away instead of being absorbed into the ground, they’re no longer available to the next crop. That will impact yield or create additional costs if they have to be replaced with fertilizer.
- Water quality impacts
When nutrients enter streams, rivers, and lakes in high concentrations, they contribute to increased algae growth, for example, which has negative impacts on human, plant and animal life.
- Negative public perception
Manure application in the winter is a highly visible activity that can attract unwanted attention and make farmers an easy target for potential regulatory action even though there are many contributors to the phosphorus problem.
- The compaction prevention myth
Some farmers believe that because the ground is harder when frozen, it reduces the potential for soil compaction by heavy manure spreaders or liquid tankers. Unfortunately, even though the soil’s top layers may be frozen, the ground underneath is not and will still suffer the impacts of compaction.
Taking action to avoid winter spreading
The vast majority of farmers are aware of the risk posed by winter spreading and are actively taking steps to avoid it. Those who are mostly likely to spread manure in the winter have a shortage of storage or are affected by wet fall weather that prevented them from emptying their liquid manure tanks before the ground froze.
There is no single practice that will address all issues or serve as a solution on every farm, but here are some solutions that can help minimize the need for winter spreading:
Plan ahead: know how much manure storage you have and have a plan in case spreading the bulk of your farm’s manure in the fall is not possible
Storage: Cover or expand existing on-farm manure storage. For solid manure, temporary in-field storage can be a workable solution.
Adjust crop rotation: adding crops like winter wheat, winter barley or winter canola, or cover crops to a rotation can provide extra manure spreading windows throughout the year.
Follow the 4Rs: Putting the right amount in the right place at the right time and at the right rate is one of the cornerstones of best nutrient management practices and can also be used for manure application strategies.
For more information on nutrient management strategies and how to avoid winter spreading, please check out the following resources: