Scientists at the Agri Food and Biosciences Institute (AFBI) in Hillsborough, Co Down, are researching ways of reducing phosphorus (P) levels in cattle slurry and AD-plant digestate.Although the use of chemical fertilisers containing phosphate has reduced in NI in recent years, high P levels in soils remains an issue. Many dairy farms have significant P surpluses, mainly due to feeding high levels of P-rich concentrates to cows.