Potential of deep-rooting agricultural grass cultivars for increasing water infiltration and soil organic carbon

Abstract

We use a replicated plot experiment to test the potential of a Festulolium cultivar and an agricultural Cocksfoot cultivar to improve water infiltration rates and carbon sequestration against a standard ryegrass/clover ley mixture over a 3 year period. There was no difference in soil organic carbon between treatments and control over this period, but the Festulolium had higher root volume at depth where no cutting or harvesting took place. Infiltration rates were higher in the Festulolium and Cocksfoot plots in year 1, but not subsequently. Cutting and grazing of the sward and associated soil compaction appear to constrain root growth and infiltration rates. The potential for carbon sequestration requires further investigation, but the potential for flood risk reduction and water quality improvement, through increased infiltration rates, could be realised where ley harvesting intensity can be reduced.