Degradation rate of soil function varies with trajectory of agricultural intensification

• Trajectories of high and low arable intensification were defined over 35 years from the mid-1970s.
• The inputs among fields differed more than four-fold in pesticide and fertiliser applications.
• Increasing management intensity was associated with deterioration in soil properties.
• High-intensity fields were less efficient at returning yield from inputs.
• Further intensification will degrade supporting ecosystem services and is unsustainable.

Efforts to maintain or increase food production in developed agriculture would be compromised if current high-intensity production was degrading supporting ecosystem services, such as the ability of soil to function. The link between cropping intensity, defined by pesticide and fertiliser applications, and soil biophysical status was examined at 70 sites in a high-yielding region of the UK, in which cropping sequences covering a wide range of intensity had diverged from a common low-intensity origin in the 1970s. Two sequences of still low or moderate intensity based on spring cereals or a low frequency of winter cereals formed comparators for three high intensity sequences based on winter wheat and potato which together were associated with adverse effects of −30% on soil carbon content in the upper soil layer (P < 0.001), −11% on soil water holding capacity (P < 0.01) and +15% on soil bulk density (P < 0.001). Negative effects were also found in some high intensity sequences on soil macroporosity and penetrometer resistance. Even in this high-yielding region, therefore, current forms of intensification are associated with adverse trends in soil condition that may be detrimental to future production. The effects of these trends in soil condition on agricultural output now need to be quantified, and the economic burden accounted for, if fields reduce their capacity to yield or need reparation to keep them productive.