Improved Sustainability and Ecosystem Services from Seaweed Additions to an Old Agricultural Production System

Abstract

Throughout the UK, and in other areas of the northern hemisphere, where there has been human settlement from the 17th century onwards, evidence of parallel ridges can still be seen today. These ridges, sometimes called lazy beds, are a remnant of a production system that offered small, often remote communities cropping potential on land that would be considered today as less favourable or unsuitable for production. With a move away from this type of small-scale, labour-intensive production system, over the last century, communities in these areas have generally undergone a shift from self-sustainability to a reliance on the importation of human and animal feed. This has led to abandonment of these cultivation systems. As modern communities become increasingly dis-associated from historic cultural practices, living memory of the management of these systems is also now being lost. There is an argument in support of restoration of these historic systems, in light of rising global pressures for both sustainable food security and land availability for agricultural production. Such restoration should be underpinned by, scientific understanding as to how these methods were able to provide a sustainable system for cropping and yield over time, and the environmental impacts of these systems. A project has been established on the island of Grimsay (North Uist) to reinstate a series of abandoned ridges, which have not been worked in over 50 years. As part of this project a series of studies have been initiated to examine the historic management practices (and their impacts) associated with these agricultural systems. A pilot study was run to determine if the traditional use of seaweed (particularly Ascophyllum nodosum) was of benefit, or indeed essential, to the longevity of these rotational systems. This trial was placed within the wider context of an experiment investigating the ecosystem impacts of reinstating this type of agricultural practice and its utilisation of local, natural resources. The findings of the pilot study indicated that historical knowledge is essential in reinstating this type of production, seaweed is both a required and sustainable addition to the system, ecosystem impacts were minimal and that production was both viable and greatly increased when labour was available.