The Soil Remembers

Core Ideas Sustainability can only be measured over long time periods. To evaluate sustainability, therefore, we need a way of keeping track—a memory. Soil offers such a memory because the soil stays. An underlying aim of soil science is to extract and describe soils' memories. Terrestrial ecosystems worldwide face mounting stresses and upheavals, mostly from human demands and interferences. Our search for better ways of living on these lands, however, is constrained by a most vexing variable: time . The final outcomes of our management choices—well intended or not—will often fully emerge only after decades, when we are no longer there to see them. A way around this dilemma is to view a longer span of time by studying the land's own memories, notably those in the soil. Most ecosystem elements flicker and fade, much as we do, but the soil stays, … and the soil remembers. In this essay, I propose that the fundamental aim of soil science is to extract and describe the narratives embedded in soils' memories, and I ponder some ways of doing that. This guiding motive, perhaps, may offer hope not only for our science but also for our lands everywhere—on which we and those who follow us will always depend.