Black carbon influence on urban soil ecosystem services: from its contribution to the soil carbon cycle to its role in mitigating the risks of heavy metals exposure into urban horticulture produce

Grantham Scholar Marta Crispo now works at the Soil Association as a Senior Technical Officer. At the Grantham Centre she researched black carbon influence on urban soil ecosystem services. 

The project

Urban soils underpin the provision of all ecosystem services delivered by urban greenspaces which are essential in strengthening urban resilience and mitigating many of the environmental and health challenges faced by urban populations.

Understanding how to enhance ecosystem service provision by urban soils is crucial to support future greenspace management strategies, such as urban horticulture expansion or the increased multifunctionality of urban greenspaces. Through different experiments and field studies the role of urban soils in carbon sequestration, pollutant bioavailability and mitigation, urban food and nutritional security has been explored, highlighting the crucial contribution of soil black carbon across all these.

Black carbon in the form of soot was demonstrated to play an active role in urban soil carbon dynamics by both suppressing the mineralisation of soil labile organic carbon and contributing to soil CO2 effluxes. Field experimental results revealed that soil application of an engineered form of black carbon (biochar) at the rate of 20 t ha-1 to a clayey loam urban soil under three different vegetation covers did not influence urban soil ecosystem service provision.

The first UK-wide assessment of heavy metals and metalloids concentrations (total and bioavailable) across UK urban horticultural soils demonstrated that growing food across these soils poses a low risk to the urban grower’s health and that soil black carbon contributes to mitigating the risk of heavy metals and metalloids uptake into urban horticulture produce.

A large-scale field study showed that long-term exposure to heavy metals and metalloids through consumption of urban horticulture produce is unlikely to pose detrimental human health risks. It also demonstrated that the consumption of urban horticulture produce contributes to the daily intake of all essential minerals, but their concentrations is often lower than those found in equivalent commercial horticultural crops.

Outreach and impact

Climate Commission

Marta is a Student Commissioner at EAUC (the Alliance for Sustainability Leadership in Education). This is a unique partnership of higher and further education organisations. Specifically, it aims to bring the education sector firmly into the climate change debate. If you want to find out more, read Grantham Scholar and the Climate Commission.

And Marta’s work with the Commission was covered in University World News. In this piece Marta said: ‘Students make up 7% of the UK population. We will have a huge impact through our lives and careers on the sustainability of the world. We are the ones that are inheriting pollution, melting ices and extreme weather events.’ If you want to find out more, you can read Climate commission unveils toolkit for university leaders.

My Harvest

Marta is part of MyHarvest, which estimating the contribution of home-grown fruit and vegetable crops on UK food production.

a poster for the Time Is Now which 'reads there is no planet b' by Marta Crispo
Time Is Now

Time Is Now: mass lobby

In June 2019 a group of Grantham Scholars went to the Time Is Now protests in London, where they met with Sheffield Central MP Paul Blomfield. Before the event, Marta explained why she was attending. Read: The Time Is Now: Grantham Scholars at ‘mass lobby’.

Social media

You find Marta Crispo on LinkedIn.

Marta Crispo’s publications

Marta Crispo, Duncan D. Cameron, Will Meredith, Aaron Eveleigh, Nicos Ladommatos, Ondřej Mašek, Jill L. Edmondson, Opening the black box: Soil microcosm experiments reveal soot black carbon short-term oxidation and influence on soil organic carbon mineralisation, Science of The Total Environment, Volume 801, 2021, 149659, ISSN 0048-9697,

Marta Crispo, Miriam C. Dobson, Roscoe S. Blevins, Will Meredith, Janice A. Lake, Jill L. Edmondson,
Heavy metals and metalloids concentrations across UK urban horticultural soils and the factors influencing their bioavailability to food crops, Environmental Pollution, Volume 288, 2021, 117960, ISSN 0269-7491,