Steven A Banwart

University of Leeds · Earth Surface Science Institute (ESSI)

Closing the loop in the flow of C, nutrients and water between agriculture, the human diet and sanitation services offers benefits for humanity across multiple platforms of public health, food...

The fixation of environmentally hazardous Cr(VI) in soils is largely attributed to its retention by iron (Fe) (oxyhydr)oxides in the soil environment, which are prevailingly associated with organic carbon (OC). The effect of OC with different binding strengths on Cr(VI) adsorption and the mobility and fate of Cr(VI) during aging of Fe (oxyhydr)oxid...

Quantifying soil structural dynamics and aggregate turnover is important in understanding soil organic carbon (SOC) stocks, particularly over decadal and larger time scales. Until now it has remained unclear clear how soil aggregate size and its associated carbon respond to both long-term soil fertility and climate change. Here, we explore changes...

Nature-based Solutions (NBS) have been increasingly advocated as means of achieving a greener and sustainable future. Although discussion on the definition, scale and applicability of NBS in country and city-level agendas are ongoing, NBS have received less attention in terms of them supporting country-level approaches to Disaster Risk Reduction (D...

The persistence of organic carbon (OC) in natural environments is widely attributed to mineral protection, especially by iron (Fe) (oxyhydr)oxides. The effect of OC binding strength on the aging of Fe (oxyhydr)oxides and the mobility and fate of OC during aging however, is unknown. Here we investigate how OC binding strength controls the aging of f...

Achieving national targets for net-zero carbon emissions will require atmospheric carbon dioxide removal strategies compatible with rising agricultural production. One possible method for delivering on these goals is enhanced rock weathering, which involves modifying soils with crushed silicate rocks, such as basalt. Here we use dynamic carbon budg...

Soil degradation remains a challenge in African highlands, where land management lacks a strong context‐specific evidence base. We investigated the impacts of recently implemented soil and water conservation (SWC) practices – farmyard manure addition, incorporation of crop residues in soil and Fanya juu terracing under agroforestry system on soil h...

This paper provides an outline of a new interdisciplinary project called FixOurFood, funded through UKRI’s ‘Transforming UK food systems’ programme. FixOurFood aims to transform the Yorkshire food system to a regenerative food system and will work to answer two main questions: (1) What do regenerative food systems look like? And (2) How can transfo...

Soils form the skin of the Earth’s surface, regulating water and biogeochemical cycles and generating production of food, timber, and textiles around the world. Changes in soil and its ability to perform a range of processes have important implications for Earth system function, especially in the critical zone (CZ)—the area that extends from the to...

An expanded circular economy between agriculture and sanitation waste (sewage) can recycle essential resources for agriculture through the recovery of water, biomass, and nutrients from sewage at scale. Doing so can help to increase or maintain soil productivity and support agricultural outputs; produce heat and power; reduce Green House Gas (GHG)...

This reports summarizes some of the findings of the circular economy team at The University of Leeds, with partners in the US and China. It highlights the potential for the agriculture-sanitation circular economy to sustain soil fertility, preserve environmental integrity and mitigate climate change.

Attachment assays of a Pseudomonas isolate to fused silica slides showed that treatment with DNaseI significantly inhibited cellular adsorption, which was restored upon DNA treatment. These assays confirmed the important role of extracellular DNA (eDNA) adsorption to a surface. To investigate the eDNA adsorption mechanism, single-molecule force spe...

The economic valuation of ecosystem services derived from Earth's critical zone has primarily concentrated on vegetation and surface waters or on a few selected aboveground services; however, the economic value of ecosystem services provided by the atmosphere and shallow lithosphere has not yet been considered substantially. In order to address thi...

Three novel permeable reactive barrier (PRB) materials composed of Cu/Fe with 0.24% and 0.43% (w/w) Cu loadings or Fe0 supported on wheat straw were prepared (termed materials E, F and G). These materials exhibited excellent pollutant removal efficiency and physical stability as well as the ongoing release of organic carbon and iron. Column experim...

Mafic igneous rocks, such as basalt, are composed of abundant calcium- and magnesium-rich silicate minerals widely proposed to be suitable for scalable carbon dioxide removal (CDR) by enhanced rock weathering (ERW). Here, we report a detailed characterization of the mineralogy, chemistry, particle size and surface area of six mined basalts being us...

The accumulation of sulfonamides in the soil environment possessed the potential to change soil microbial community and function. Metabolomics is capable of providing insights into the carbon metabolic pool and molecular mechanisms associated with external stressors. Here we evaluated alternations in soil bacterial community and soil metabolites pr...

40% of UK peatlands have been drained for agricultural use, which has caused serious peat wastage and associated greenhouse gas emissions (carbon dioxide ‐ CO2, methane ‐ CH4). In this study we evaluated potential trade‐offs between water table management practices for minimising peat wastage and greenhouse gas emissions, whilst seeking to sustain...

Rare earth elements (REEs) are in increasing demand due to rapidly rising use in consumer technology, the automotive industry and in renewable energy generation systems, amongst other technology sectors. Ion-adsorption type REE ore deposits are currently being exploited in China's southern provinces and there is increasing interest in identifying p...

Improving soil health is necessary for increasing agricultural productivity and providing multiple ecosystem services. In the African Highlands (AH) where conversion of forests to cultivation on steep slopes is leading to soil degradation, sustainable land management practices are vital. Farmers’ awareness of soil health indicators (SHI) influences...

Agriculture is a major contributor to environmental degradation and climate change. At the same time, a growing human population with changing dietary preferences is driving ever increasing demand for food. The need for urgent reform of agriculture is widely recognized and has resulted in a number of ambitious plans. However, there is credible evid...

Extracellular polymeric substances (EPS) play a dominant role in protective biofilms. However, studies exploring the underlying protective mechanism of EPS have mainly focused on activated sludge, whereas their positive roles in protecting soil microbes from environmental stress have not been elucidated. In this study, we revealed the response of s...

DOC and nitrate in farmland represent key chemical species that determine the water quality in the Karst Critical Zone (KCZ). The work reported here focuses on quantifying fluxes of these species in an experimental farm site (University of Leeds Farm, UK) overlying a dolomitic karst aquifer of Permian age. In this research, the Transect Method was...

Antibiotic resistance and rising CO2 levels are considered among the most significant challenges we will face in terms of global development over the following decades. However, the impact of elevated CO2 on soil antibiotic resistance has rarely been investigated. We used a free-air CO2 enrichment system to investigate the potential risks posed by...

Enhanced silicate rock weathering (ERW), deployable with croplands, has potential use for atmospheric carbon dioxide (CO2) removal (CDR), which is now necessary to mitigate anthropogenic climate change¹. ERW also has possible co-benefits for improved food and soil security, and reduced ocean acidification2–4. Here we use an integrated performance m...

Land-based enhanced rock weathering (ERW) is a biogeochemical carbon dioxide removal (CDR) strategy aiming to accelerate natural geological processes of carbon sequestration through application of crushed silicate rocks, such as basalt, to croplands and forested landscapes. However, the efficacy of the approach when undertaken with basalt, and its...

Sub-Saharan Africa (SSA) faces climate change and food insecurity challenges, which require action to create resilient farming systems. Conservation agriculture (CA) is widely promoted across SSA but the impacts on key soil physical properties and functions such as soil structure and hydraulic properties that govern water storage and transmission a...

Earth’s critical zone is the physical layer contained between the top of the vegetation canopy and the depth of the circulating groundwater below the land surface. The critical zone is defined within the study of Earth natural sciences as the unique terrestrial biophysical system that supplies most life-sustaining resources for humans. A feature of...

Aggregates are the structural units of soils, and the physical stability is considered to be a keystone parameter of soil quality. However, little is known about the evolution of the pore system in aggregates and its importance in defining aggregate stability. In this paper, we investigated the pore system and stability of three dominant macroaggre...

This book presents a novel and systematic social theory of soil, and is representative of the rising interest in ‘the material’ in social sciences. Bringing together new modes of ‘critical description’ with speculative practices and methods of inquiry, it contributes to the exploration of current transformations in socioecologies, as well as in pol...

While nature based solutions (NBS) are often more cost-effective than traditional grey infrastructure alternatives, the barriers to implementation are more complex and are linked to change management, education, partnership working, and securing investment for an emerging and less understood sector. More information about NBS implementation issues...

The concept of planetary health acknowledges the links between ecosystems, biodiversity and human health and well-being. Soil, the critical component of the interconnected ecosystem, is the most biodiverse habitat on Earth, and soil microbiomes play a major role in human health and well-being through ecosystem services such as nutrient cycling, pol...

Nature Based Solutions (NBS) are classified by the European Commission (EC) as addressing societal challenges by providing solutions that are inspired and supported by nature, which are cost-effective, simultaneously provide environmental, social, and economic benefits and help build resilience. Implementation of NBS across urban and rural landsca...

Viruses and bacteria which are characterized by finite lives in the subsurface are rapidly transported via fractures and cavities in fractured and karst aquifers. Here, we demonstrate how the coupling of a robust outcrop characterization and hydrogeophysical borehole testing is essential for prediction of contaminant velocities and hence wellhead p...

A summary presenting the challenges for soil carbon sequestration research, hypothesis to be further tested and key research (and innovation) products.

Permeable reactive barriers (PRBs) are an environmentally-friendly, cost-effective in-situ technology that can be used to remediate polycyclic aromatic hydrocarbons (PAHs)-contaminated groundwater. In this study, PRBs of two different materials (A and B) that relied on microbes self-domestication mechanism were designed and tested. The materials A...

Contaminants that are highly soluble in groundwater are rapidly transported via fractures in mechanically resistant sedimentary rock aquifers. Hence, a rigorous methodology is needed to estimate groundwater flow velocities in such fractured aquifers. Here, we propose an approach using borehole hydraulic testing to compute flow velocities in an un-f...

Peatlands are globally important areas for carbon preservation; although covering only 3% of global land area, they store 30% of total soil carbon. Lowland peat soils can also be very productive for agriculture, but their cultivation requires drainage as most crops are intolerant of root-zone anoxia. This leads to the creation of oxic conditions in...

Introduction: Humans generate millions of tons of waste every day. This waste is rich in crop nutrients, yet its fertiliser value remains underutilized. Improved sanitation in urban areas is essential for public health, but it can also contribute to food security by reducing reliance on mineral fertilizers, and mitigate climate change via carbon se...

Soil is the central interface of Earth's critical zone—the planetary surface layer extending from unaltered bedrock to the vegetation canopy—and is under intense pressure from human demand for biomass, water, and food resources. Soil functions are flows and transformations of mass, energy, and genetic information that connect soil to the wider crit...

Long-term environmental research networks are one approach to advancing local, regional, and global environmental science and education. A remarkable number and wide variety of environmental research networks operate around the world today. These are diverse in funding, infrastructure, motivating questions, scientific strengths, and the sciences th...

This chapter describes some of the most common methods used to characterize the cell surface properties of the bacterial cells. As a case study, the focus of this chapter is on Sphingomonas spp., Sph2, which is a Gram negative and hydrophilic bacterial strain. The species used in this research was isolated from groundwater at a phenol-contaminated...

Earth's Critical Zone sustains terrestrial life and consists of the thin planetary surface layer between unaltered rock and the atmospheric boundary. Within this zone, flows of energy and materials are mediated by physical processes and by the actions of diverse organisms. Human activities significantly influence these physical and biological proce...

Soil structure is known to influence microbial communities in soil and soil aggregates are the fundamental ecological unit of organisation that support soil functions. However, still little is known about the distribution of microbial communities and functions between soil aggregate size fractions in relation to land use. Thus, the objective of thi...

For several billion years, microorganisms and the genes they carry have mainly been moved by physical forces such as air and water currents. These forces generated biogeographic patterns for microorganisms that are similar to those of animals and plants (1). In the past 100 years, humans have changed these dynamics by transporting large numbers of...

Enhanced weathering (EW) aims to amplify a natural sink for CO2 by incorporating powdered silicate rock with high reactive surface area into agricultural soils. The goal is to achieve rapid dissolution of minerals and release of alkalinity with accompanying dissolution of CO2 into soils and drainage waters. EW could counteract phosphorus limitation...

In this research, bacterial cell attachments to hematite, goethite and aluminium hydroxide were investigated. The aim was to study the effects of these minerals' hydrophobicity and pH-dependent surface charge on the extent of biofilm formation using six genetically diverse bacterial strains: Rhodococcus spp. (RC92 & RC291), Pseudomonas spp. (Pse1 &...

This paper outlines the development of an integrated interdisciplinary approach to agri-food research, designed to address the ‘grand challenge’ of global food security. Rather than meeting this challenge by working in separate domains or via single-disciplinary perspectives, we chart the development of a system-wide approach to the food supply cha...

Globally, rapid urbanization, along with economic development, is dramatically changing the balance of biogeochemical cycles, impacting upon ecosystem services and impinging on United Nation global sustainability goals (inter alia: sustainable cities and communities; responsible consumption and production; good health and well-being; clean water an...

Most of soil functions depend directly or indirectly on soil water retention and transmission, which explains their importance for many environmental processes within Earth's Critical Zones. Soil hydraulic properties are essential in irrigation and drainage studies for closing water balance equation, for predicting leaching of nutrients, for water...

This chapter summarizes the methods, results, and conclusions of a 5-year research project (SoilTrEC: Soil Transformations in European Catchments) on experimentation, process modeling, and computational simulation of soil functions and soil threats across a network of European, Chinese, and United States Critical Zone Observatories (CZOs). The stud...

Clay minerals are involved in the formation of soil structure and soil cation exchange capacity through interaction with soil organic matter. Through these interactions, clay minerals contribute to soil functions and the delivery of soil ecosystem services. Although clay minerals are considered stable over long periods of time, recent studies have...

In the next four decades, humanity needs to double food and energy production and increase the supply of clean water by over 50% while mitigating and adapting to climate change. A central element in the strategy of addressing these major environmental challenges is to maintain the central role of Earth's essential soil functions and related ecosyst...

Soil aggregation and development of soil structure play a crucial role in determining soil functions and ecosystem services in Earth's Critical Zone. Soil organic matter (SOM) is the main constituent that binds mineral particles together into larger-sized aggregates. Many theoretical concepts have been proposed to explain soil aggregation and SOM a...

Soil aggregates are microhabitats for microorganisms, and directly influence microorganisms that live within and are influenced by microorganisms in return. Two methods are used to isolate soil aggregates by their size: dry sieving (sieving air-dried soil) and wet sieving (sieving soil in water). Wet-sieving methods are generally considered to repr...

Soil organic carbon (SOC) is a strong determinant of soil fertility through its positive effects on soil structure and soil chemical and biological properties which in turn stimulate primary production. The objective of this work was to simulate field sites that represent different land uses and management practices in three continents, in order to...

Food security should be addressed in relation to soil sustainability and sustainable land care, and examined within the science framework of Earth's critical zone as an integrated system that includes Earth surface interactions, connected to soil functions, and ecosystem services. There is a great need to develop critical zone mathematical models t...

Soil hydrology controls the terrestrial water cycle and the transport of substances to influence the environmental quality of Earth's critical zone (CZ). Soil and water management in agroforestry systems (AF) is able to reduce soil nitrogen losses and to alleviate secondary salinity in some regions of the world by reducing subsurface lateral flow....

Most of soil functions depend directly or indirectly on soil water retention and transmission, which explains their importance for many environmental processes within Earth's Critical Zones. Soil hydraulic properties are essential in irrigation and drainage studies for closing water balance equation, for predicting leaching of nutrients, for water...

Key messages • Soil is an important habitat for thousand millions of organisms. • Soil biodiversity is extremely diverse in shapes, colours, sizes and functions. • Soil biodiversity is globally distributed, from deserts to polar regions through grasslands, forests, urban and agricultural areas. • Soil biodiversity supports many services essential t...

SPE EA Pôle BIOME The Atlas is divided in 8 chapters covering all the aspects of soil biodiversity: - Chapter I: The soil habitat - Chapter II: Diversity of soil organisms - Chapter III: Geographical and temporal distribution - Chapter IV: Ecosystem functions and services - Chapter V: Threats - Chapter VI: Interventions - Chapter VII: Policy, educa...

The US National Science Foundation (NSF) has pioneered an integrated approach to the study of Earth's Critical Zone by supporting a network of Critical Zone Observatories (CZOs). The CZOs are intensively studied and monitored sites with a focus on a range of Critical Zone processes that are well represented at the various sites. The initial network...

Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions. We show th...