A new summary sheet around deep nitrogen accumulation and sources has been produced by the team highlighting the findings and relevance for policy making and practice. They found that land use and critical zone features (e.g. thickness of loess deposit, water regime) are key determinants of N accumulation patterns where agricultural inputs – e.g. fertiliser, manure and organic sources – are significant contributors. In the Loess plateau region, accumulated nitrate introduced by human activities is mainly distributed in the upper vadose zone (above 30 m), indicating there is currently a low risk of nitrate leaching into groundwater. A copy of the Summary sheet is here.