Teagasc research is confirming that autumn-grown catch crops are helping to reduce nutrient run-off from soils in tillage areas.
A catch crop is a fast-growing crop that is grown between successive plantings of a main crop.
According to Teagasc advisor Matt Boland, the Agricultural Catchments Programme was set up in 2008 to monitor and evaluate Ireland’s requirements under the EU Nitrates and Water Framework Directives.
“There was also a remit established to provide measurements regarding the efficacy of Ireland’s nitrates derogation,” Boland said.
“We are currently in the fourth phase of the programme. Each phase is four years long.
This is the second year of phase four, which has seen us take on the added measure of assessing greenhouse gas emissions.
Boland made his presentation from the Castledockrell catchment area of Co. Wexford, which is heavily reliant on tillage.
Most of the farmers in that locality grow crops of spring barley, which are destined for malting.
“Soils here are light and free draining, which suit cereal production,” he said.
“Nitrogen is the main nutrient at risk of being lost to water.
With spring barely being very much the predominant crop, it leaves the soils throughout the catchment area very much open for long periods of the year.
GLAS
According to Boland, the introduction of the Green Low-Carbon Agri-Environment Scheme (GLAS) has given farmers in the Castledockrell catchment the opportunity to sow catch crops.
“A nominal fee of €155/ha is available to allow farmers grow these crops. This meant there was a green crop on the stubble ground over winter,” Boland added.
“In turn, this is reducing the risk of nutrient run-off. Where nitrogen release is an issue over the winter period, the catch crop has been able to avail of this available nutrient.”
Teagasc has high resolution water quality monitors in each catchment.
Boost to water quality
Boland confirmed that the growing of catch crops is delivering a real and meaningful benefit in terms of boosting water quality in high risk areas.
“We can only see benefits coming from catch crops sown out in areas where spring cereal crops predominate,” he said.
“Hopefully once the GLAS scheme ends, farmers will continue to grow catch crops in order to reduce nutrient losses to water.”
Subsequently, in the following spring, the ploughing-in of the catch crop helps to further boost soil quality.