The Wintering Site Assessment and Design Tool can help producers identify environmental risks associated with in-field winter feeding sites and systems.
The tool can also be used to compare different situations and to adopt beneficial management practices (BMPs) to address risks, said provincial nutrient management specialist Trevor Wallace.
The greatest environmental risk from wintering sites is the potential of water contamination from run-off carrying nutrients, pathogens and sediments. Nutrient accumulation in the soils under in-field feeding systems is another factor that can significantly increase the risk of nutrient loss. The goal is to take advantage of the nutrients from in-field feeding systems and not lose them.
The tool evaluates five main wintering site factors: site characteristics, feeding strategies, bedding and shelter management, water source management, and post-wintering site management. The tool looks at factors such as flooding frequency, stocking rate, run-off, bedding and shelter, water system management and post-site management to determine the risk of nutrient loss.
For example, it can be used to compare bale grazing (an imported feeding system) to swath grazing (a non-imported feeding system).
“These two feeding systems differ in their risk of nutrient accumulation,” said Wallace.
“With a swath-grazing system, animals generally move down the field with the feed, meaning that the nutrients are also moved across the field. With bale grazing, the animals go to where the bales are and all the nutrients from the feed is generally deposited in a small area potentially resulting in nutrient accumulation. With a bale-grazing system we can use the bales to direct the animals where we want them to go. With a swath-grazing system they follow the swaths.”
The Wintering Site Assessment and Design Tool provides a way to assess the potential risk of a feeding system at a site and suggests BMP options to address identified risks.
“The objective is to make sure the site selected for the winter feeding system is meeting the animal’s needs, minimizes the risk to the environment, and maximizes the benefit of the in-field feeding system,” said Wallace.
The Wintering Site Assessment and Design Tool is available by calling ARD’s publication office at 1-800-292-5697, or via download at www.agriculture.alberta.ca/manure.