Winter Grazing
The issue
Break-feeding stock on a winter crop results in bare, often pugged soil, with concentrated amounts of effluent on the soil surface. Rainfall and the resultant overland flow can transport sediment and effluent into drains and waterways. This results in the loss of valuable topsoil which can silt up drains and affect tile outfalls as well as increasing the number of bugs and pathogens in waterways.
Environment Southland has introduced a rule regarding intensive winter grazing to help minimise the effects of this practice on water quality.
Intensive winter grazing is defined as the grazing of stock between May and September inclusive, on fodder crops or pasture to the extent that the grazing results in significant devegetation
Significant devegetation is defined as removal of, or damage to, vegetation caused by stock access or grazing that results in the exposure of large areas of bare ground and / or pugging of the soil.
The solution
The simple and cost effective solution is the use of electric fencing and the retention of a filtering buffer zone beside waterways. Farmers need to ask themselves "where is water going to exit my swede paddock during heavy rain?" The answer will identify the hotspots and swales in the paddock which will carry overland flow. A wide buffer zone can be incorporated into these exit points and protected by electric fencing when break-feeding the crop. This ungrazed riparian margin will help trap sediment and nutrients within the paddock, improving water quality and saving farmers money in the long run.
From 1 May all stock must be kept at least 3 metres away from any waterways during intensive winter grazing.
Things to think about when planning and feeding out winter crops include:
- Where possible choose paddocks away from waterways to plant winter crops
- Identify swales in the paddock that will carry overland flow when it rains heavily and leave them un-ploughed as a grassed waterway. These can be protected with electric fencing when break-feeding the crop
- When cultivating keep the plough line back a minimum of 3m from the edge of drains and waterways
- Break-feed towards waterways as this provides a wider buffer for filtering runoff and retaining nutrients within the paddock than if grazing beside the waterway first
- Ensure the 3m buffer is fenced to protect it from stock and comply with the winter grazing rule
Complying with stock access rules
Aside from intensive winter grazing, farmers should keep stock out of waterways at all times because of the impact they have on water quality.
Because of the practical difficulties associated with fencing stock out of waterways in some situations, Environment Southland has a permitted activity rule for general stock access to surface water.
However there are conditions attached to this rule that must be met at all times including a requirement to comply with water quality standards, and to avoid significant devegetation and alteration of the bed and banks of the waterway.
When cattle and deer have unrestricted access to a waterway or are frequently crossing it, for example dairy cows on their way to and from the milking shed, water quality standards are likely to be breached.
The use of the beds of lakes and rivers for supplementary feeding, fodder crops or as stock runoff is prohibited.
To find out more about the rules around intensive winter grazing download the factsheet below:
Environment Southland is the brand name of Southland Regional Council.