As part of the CPES project, Portsmouth Water have commenced their cover crop trial at a farm within the South Downs groundwater catchment.
Working with a local farmer and environmental consultancy ADAS, Portsmouth Water have established cover crops after the main summer harvest in a trial to quantify the effects on ecosystem services provided by soil. Portsmouth Water hope that demonstrating the benefits of these cover crops to the environment and to the farmer, will encourage the use of this practice across their groundwater catchments.
Cover crops such as barley, oats, radish and ryegrass planted after the main summer harvest provides winter cover, which, amongst other benefits, can help to reduce erosion, reduce nitrate leaching, increase carbon sequestration, and improve soil health. Portsmouth Water will be focussing the trial on the effects of cover crops on nitrate leaching as leaching of nitrate fertilizer applied to agricultural land is causing drinking water standards for nitrate to be exceeded at some of their groundwater abstraction points.
Cover crops also benefit farmers by cutting fertilizer costs, reducing the need for herbicides and other pesticides, and improving yields by enhancing soil health and conserving soil moisture. The trial will also focus on quantifying these socio-economic benefits to the farmer. Along with this evidence, incentive payments to farmers could also encourage the use of this practice on farms across their groundwater catchments.