Buffer zones play an important role in helping to prevent sediment, nutrient loss and pesticides entering watercourses.
Current regulations require the establishment of a 3m uncultivated buffer zone next to watercourses for all non-grass crops.
Teagasc tillage specialist, Ciaran Collins, further explained:
“While a 3m uncultivated buffer zone is mandatory next to all watercourses for non-grass crops, the buffer increases to 6m for late harvested crops.
“A late harvested crop includes vegetables removed after September 15, as well as fodder beet, sugar beet, main crop potatoes and maize.
“Cereal crops and beans are excluded from this requirement.”
The minimum, uncultivated buffer width of 6m also applies to the intersecting proportion of the watercourse.
“This is where the natural slope of the field directs water run-off into the river,” he added.
Buffer zones
According to the Teagasc representative, nitrate leaching is one of the major issues on light, free-draining soils typically used in crop production.
“Nitrogen does not bind tightly to the soil and is susceptible to leaching when excess nitrogen is applied, especially after heavy rainfall.
“Phosphorous is most prone to loss from low permeability clay soils or soils which are peaty in nature. This loss occurs through overland flow of water which carries sediment and phosphorous into drains and surface waters.
“When we see brown water flowing into a watercourse following heavy rain, this normally contains high levels of phosphorous,” he explained.
Buffer strips are a way of breaking the pathway of nutrients by slowing water runoff, trapping sediment and enhancing infiltration of the soil.
As the end of the prohibited period for the spreading of organic manure approaches, it is important to remember that low emission slurry spreading (LESS) equipment must be used to apply livestock manure to arable land or else the livestock manure or it must be incorporated within 24 hours.
Pig slurry is low emissions only.
The mandatory buffer zone for organic manure spread near watercourses is 5m, but this increases to 10m for the first two weeks after the prohibited period.
E.g., the Zone A slurry application buffer width is 10m between January 13 and January 26.
This figure reduces to 5m thereafter.