Current Research

Managing human excreta for soil, food and nutrient security

Background

Future Farming Needs to Regenerate Soil and Soil Health

Healthy soils are crucial for the provision of food. Soil degradation is a serious threat to long-term agricultural productivity. There is a need to actively strive to regenerate soil and soil health through soil management practices that are beneficial for soil organic matter, soil organisms, and soil biodiversity.

Nutrients in Human Excreta Need to be Recycled to Agriculture

Sustaining agricultural productivity requires that nutrients taken up by crops are replenished. Currently, global food production largely relies on nutrients mined from finite reserves. Recycling nutrients in human excreta to agriculture can make important contributions to more circular nutrient flows and improved food security.

Human Excreta Need to be Managed for Nutrient Cycling and Soil Regeneration

In recent years, a broad variety of technological options have become available to recover nutrients in human excreta. Soil regeneration and long-term soil health, however, have generally not been a primary objective in these developments. There is a need to identify opportunities and best practices to better align the management of human excreta with the needs of long-term soil fertility and health.

Purpose

Leverage Knowledge Base and Debates Surrounding Nutrient Cycling and Soil Regeneration

This research asks: how can the recycling of nutrients in human excreta to agriculture best support farming systems and practices that regenerate rather than impoverish soil? Is a focus on phosphorus and possibly nitrogen and potassium sufficient, or do we also need to address micronutrients and organic matter in order to enable long-term soil fertility and health? The aim is to help key actors shaping the future management of human excreta to better leverage the knowledge base and debates surrounding both nutrient recycling and soil regeneration.

Approach

Exposing Preferences and Assumptions Associated with Different Options and Assessment Tools

This research does not attempt to provide a single definitive answer or best solution. Rather, it aims to expose the often implicit preferences and assumptions associated with different options to recycle nutrients and organic matter in human excreta to agriculture and regenerate soil, as well as with different assessment tools used to find the best option in a given context. Different perspectives and aspects will be explored using a mixed methods approach guided by a range of questions at the intersection between nutrient recycling and soil regeneration. Specific methodological choices will be made as the research project proceeds.

Outcomes

Future Infrastructure for Human Excreta Management Supports Long-Term Soil Health

There is currently a window of opportunity to incorporate the needs of soils into the design of infrastructure for managing human excreta. Bringing forth different perspectives should allow for a more nuanced understanding of potential leverage points, discrepancies, and blind spots in the knowledge base and debates surrounding nutrient recycling and soil regeneration. Hopefully, this will promote infrastructure that is designed to facilitate both nutrient recycling and soil regeneration, assessment tools that adequately capture aspects of both nutrient recycling and soil regeneration, and an awareness that this is important.

Research Grant

Recycling organic matter and nutrients from sanitation to farming systems to regenerate soil and land: Identifying approaches that are feasible and preferable

Funder: Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (Formas)
Type: Mobility Starting Grant for Young Researchers
Role: Principal Invenstigator
Value: SEK 3.7 million (approx. EUR 370 000 or CAD 560 000)
Period: 2017-2020