More than £7m of government money has been made available to farmers to help tackle the problem of water pollution.
Farmers in 50 catchment areas across England can apply for grants of up to £10,000 from the Catchment Sensitive Farming Capital Grants Scheme.
The grants will cover improvements to reduce diffuse pollution from farming, including constructing fencing near rivers and streams, adding water troughs and roofing manure and silage stores.
Farmers will have to compete for the grants, with applications from farms in target areas standing the best chance of being selected for funding.
The window for this year's grants, funded by the Rural Development Programme for England, opened on 1 March and will close on 30 April 2011.
Helen Phillips, Natural England chief executive, said: "Reducing diffuse pollution at source brings significant benefits to people and wildlife downstream and means less public money has to be spent on water treatment.
"I'm delighted that a fifth year of the capital grants scheme has now begun, because it will support farmers and land managers involved in this vital work."
Farmers can check whether their land is in a priority catchment area by checking the DEFRA website.
To receive an application pack email download it.
Alternatively, packs can be obtained by telephoning 0300 060 1111 or writing to: Catchment Sensitive Farming Team, Incentive Scheme Services, Natural England, Block 7, Government Buildings, Chalfont Drive, Nottingham, NG8 3SN.