DES 3385 / Thinking Through Soil

Instructor / Seth Denizen

Seminar / Spring 2020

Department of Landscape Architecture

Graduate School of Design

Harvard University
What this course is about?

Urbanization is always a process of soil formation. Every material process that shapes the construction of the urban environment passes through the soil at some point. In Thinking Through Soil, we will use ‘soil’ as an interpretive category to guide us through the political consequences, design epistemology, and material contingency of the urban environment.

In particular, this seminar will take a close look at the Mexico City-Mezquital Valley system. The soils in the Mezquital Valley have been irrigated with untreated wastewater for longer than any other soil in the world, and are locked in a cycle of reciprocal presupposition with the desiccated soils of Mexico City’s rapidly subsiding lake-bed.

As the world’s largest experiment in wastewater agriculture, the successes and limitations of this system are of deep significance to a warming world, and provide a concrete framework for testing the possibility of designing the relation between cities and the soil they produce.


In order to undertake this case study, the history and theory of urban soil will be a subject of particular importance. The urban soil science we have inherited in the 21st century is an exquisite corpse of natural history’s many attempts to find stable forms in a material that appears formless and opaque.

The conventional forms of the soil profile that we are familiar with today, with ‘horizons’ of different colors, did not appear until the late 19th century. Minerals, rocks, organisms, and fossils were all seized upon by the representational grids of natural history in the 16th century, but soil eluded them. Existing somewhere between life and non-life, the one and the many, the part and the whole, soil was merely the detritus of rocks until the 1880s.

The result is that few materials are less legible to the conceptual machinery of modernity than soil. Revisiting the history of soil’s illegibility as a natural historical object is essential an analysis of its collision with the urban environment.