Agricultural land lacks resistance to water erosion during the wettest winters of the past decade

Abstract

With changing climate and increased frequency of wet weather extremes, increased attention is being directed towards understanding the resilience of agroecosystems and the goods and services they deliver. The world's most instrumented and monitored farm (the North Wyke Fam Platform - a UK National Bioscience Research Infrastructure) has been used to explore the resilience of sediment loss regulation delivered by lowland grazing livestock and arable systems under conventional best management. The robustness of water quality regulation was explored using exceedance of modern background (i.e. pre-World War II) net soil loss rates (i.e., sediment delivery) during both typical (2012–13, 2015–16) and the most extreme (2013–14, 2019–20, 2023–24) winters (December - February, inclusive), in terms of seasonal rainfall totals, over the past ∼decade. Exceedances of maximum modern background sediment loss rates from pasture were as high as 2.4X when scheduled ploughing and reseeding for sward improvement occurred immediately prior to the winters in question. Exceedances of maximum modern background sediment loss rates in the arable system (winter wheat and spring oats) were as high as 21.7X. Over the five monitored winters, the environmental damage costs for cumulative sediment loss from the permanent pasture system ranged from £ 163–203 and £ 197–245 ha⁻¹ to £ 321–421 and £ 386–507 ha⁻¹. Over the same five winters, environmental damage costs for cumulative sediment loss from catchments subjected to reseeding and, more latterly, arable conversion, ranged between £ 382–584 and £ 461–703 ha⁻¹ to £ 1978–2334 and £ 2384–2812 ha⁻¹. Our data provide valuable quantitative insight into the impacts of winter rainfall and land use on the resilience of sediment loss regulation.