The selected Soil Sister materials showcased here are developed as part of the ongoing “Soil Sisters” research seminars at the Yale School of Architecture. The research aimed to define “Soil Sister” material groups that support a diverse range of building material strategies that relate topsoil pollution reduction through carbon storage and material banks, as well as those that drive regenerative farming practices. All material prototypes will be visualized in an ongoing open-source “Soil Sisters” data visualization platform to be launched in Spring 2025 and will evolve “Soil Sister” product categories. The research engages interdisciplinary collaborators and intersectoral partners across ongoing research and travel seminars:

  • Spring 2023 interdisciplinary research seminar taught by Mae-ling Lokko and Anna Dyson bringing together industrial partners and academic collaborators for guest lectures, public discussions, and hands-on materials workshops aimed at centering soil health as a goal for material design.

  • Summer 2023 month-long travel studio in Ghana taught by Mae-ling Lokko with textile enterprise partner Global Mamas, the OR Foundation, GeoIntell Engineering and related local industries to explore the development of “Soil Sister” products from local to bioregional resources.

  • Ongoing Fall 2023 research project focused on the development of an open-source “Soil Sisters” data visualization platform. The platform serves as a database for defining emerging “Soil Sister” product categories: Material Bank, Carbon Sink, Non-toxic Circular, and Regenerative Farming.

  • Spring 2024 research seminar taught by Mae-ling Lokko focused on local to bioregional resources in New Haven.

  • Summer 2024 month-long travel studio in Senegal taught by Mae-ling Lokko with Raw Material Company, urbaSEN, CSFP-BTP and Hahatay Gandiol to explore the development of “Soil Sister” products across the textile, earth masonry, salt and plastic industries.

“Soil Sisters” reminds us that, in the end, everything returns to the soil, and it is by reinventing the life cycle of materials that societies will move toward higher ecological efficiency. From local soil restoration practices in Ghana and Guatemala to global supply chains of agricultural products and their waste, this multiscalar research project may contribute to broaden our understanding around soil health and how waste by-products can be upcycled into construction materials.

Gabriel Kozlowski, Juror, SOM Foundation Research Prize 2021

Soil Sisters guest panelist, Dr. Kofi Boa, from the Center for No-Till Agriculture in Ghana © CNTA

Color intensity of biobased color from a single plant can vary based on life cycle —its provenance, age, plant component and even dye processing methods over time. Circular textile design can embrace biobased color variance.

Construction of experimental earth masonry composite walls in Ghana © Mae-ling Lokko.

Textile waste in a landfill site in Accra, Ghana. Image courtesy of The Or Foundation. © The Or Foundation

Pressed and woven cotton fiberboard fiberboard panels and furniture in collaboration with the OR Foundation © Mae-ling Lokko.

Dyed textiles experimenting with shifting plant-based color using soil, mordant and plant dye mixing © Nicole de Araujo (left) and Mae-ling Lokko (right).

Across the life cycle of agricultural and food production of rice, a broad range of valuable plant material from the rice plant including stalks, hulls and "broken" rice grains are captured and recomposed within a panel as aggregate, fiber and glue.

Rice bio panel made from rice agricultural waste and rice glue by Jinrui Zhang. © Jinrui Zhang.

Color intensity of biobased color from a single plant can vary based on life cycle —its provenance, age, plant component and even dye processing methods over time. Circular textile design can embrace biobased color variance.

As conservation agriculture scales to improve soil resiliency, the design of low-carbon earth masonry can be formulated to integrate a broad range of biodiverse soil and biomass by-products. In tropical ecologies like Ghana, seasonal fiber by-products from agriculture (rice, corn) and forestry (bamboo, palm) can be used for improving the mechanical strength and hygrothermal performance of non-fired earth masonry products. Approaching the elimination of ordinary portland cement (OPC) as a binder can drive down embodied carbon and cost of earth masonry building materials; and ultimately recapture the advantages of non-toxic circular earth masonry practices.

As conservation agriculture scales to improve soil resiliency, the design of low-carbon earth masonry can be formulated to integrate a broad range of biodiverse soil and biomass by-products. In tropical ecologies like Ghana, seasonal fiber by-products from agriculture (rice, corn) and forestry (bamboo, palm) can be used for improving the mechanical strength and hygrothermal performance of non-fired earth masonry products. Approaching the elimination of ordinary portland cement (OPC) as a binder can drive down embodied carbon and cost of earth masonry building materials; and ultimately recapture the advantages of non-toxic circular earth masonry practices.

Across the globe, the rise of textile waste at the end of clothing life cycle presents an opportunity for a broad range of fiberboard and aggregate applications. Every week, 15 million second hand garments are shipped to Ghana from the United Kingdom, United States and China, transformation coastal landscapes and urban landfills. Students in the 2023 Ghana Soil Sisters research seminar visited a large market landfill site and coastal areas where textile and plastic waste accumulates and worked with project partner, the OR Foundation, to develop such textile products for furniture and fiberboard applications. 

In the Spring of 2023, the development of plant-based dyes to achieve ancient primary colors activated a methodology of dye plant color mixing and mordant variation to yield a broad spectrum of plant based color. Continuing this work with plant-dye expert Sasha Duerr in Ghana, the shifting of plant-based color using natural dye and mordant combinations can be studied to generate the full color spectrum.

Textile design prototypes and drawing (right) from biobased color variance by Maya Gamble. © Maya Gamble.