Context/problem: Growing catch crops in autumn after the main crop is known to reduce nitrate leaching and improve soil fertility. Residual effects of growing catch crops repeatedly for several years on the grain yield and grain nitrogen (N) of the following main crop, and nitrate leaching are less known. Methods: We conducted field experiments with spring barley and catch crops, including an herbicide treated bare treatment, from 2015 to 2022 at two sites in Denmark, differing in soil type and climatic conditions…