The influence of nitrogen and early drainage on production from grazed and cut grassland restored after opencast mining

A review of past and present grassland management on land restored from opencast mining suggests that the most noticeable changes have been increased nitrogen fertiliser use and earlier installation of permanent under‐drainage. A programme of research is described which aimed to examine the effect of early drainage on perennial ryegrass (Lolium perenne S23) grown for grazing, frequent cutting or silage production on sites previously opencast mined for coal, and to consider how these options affected both the short‐term productivity and the long‐term restoration of the soil. The results demonstrate that satisfactory herbage production is possible on restored land provided moderate levels of fertiliser are applied. Grass was utilised at high levels of intensity with no detrimental effects on sward or soil. Highest yields were obtained when grass was cut for silage, and under this regime early drainage led to a significant increase in herbage production each year of the study. When grazing was practised, drainage only led to increased total herbage production in wet years although benefits were seen in spring and in the overall sheep carrying capacity of the land. Clover inclusion in the cut swards only increased yield when less than 200 kg N ha −1 year −1 was applied.