Defining sustainable limits during and after intensification in a maritime agricultural ecosystem

ABSTRACTIntroduction: Intensification of agricultural ecosystems in the 20th century proceeded by a series of innovations that initially ensured food security, but had negative consequences for the in-field and wider environments. A case study in the north Atlantic zone maritime cropland of the UK identified three phases: (1) reorganization between 1940 and 1960, (2) intensification leading to tripling of grain output (1960–1990), and (3) a leveling of output (1990–2015).Outcomes: Innovations that caused the changes together with their effect on life forms, ecological processes and the evolving social, economic and biophysical conditions are identified. Attempts to design future sustainable systems are hampered by the absence of a baseline before intensification, by inadequate knowledge of in-field processes, and by uncertainty over “safe ranges” in which processes can operate without causing long-term system decline. Safe ranges are examined for three attributes recorded over all three phases, namely gra...