Iron Chelation in Soil: Scalable Biotechnology for Accelerating Carbon Dioxide Removal by Enhanced Rock Weathering.

Enhanced rock weathering (EW) is an emerging atmospheric carbon dioxide removal (CDR) strategy being scaled up by the commercial sector. Here, we combine multiomics analyses of belowground microbiomes, laboratory-based dissolution studies, and incubation investigations of soils from field EW trials to build the case for manipulating iron chelators in soil to increase EW efficiency and lower costs. Microbial siderophores are high-affinity, highly selective iron (Fe) chelators that enhance the uptake of Fe from soil minerals into cells.

Mitigating Contaminant-Driven Risks for the Safe Expansion of the Agricultural-Sanitation Circular Economy in an Urbanizing World.

The widespread adoption of an agricultural circular economy requires the recovery of resources such as water, organic matter, and nutrients from livestock manure and sanitation. While this approach offers many benefits, we argue this is not without potential risks to human and environmental health that largely stem from the presence of contaminants in the recycled resources (e.g.

Enhanced weathering in the US Corn Belt delivers carbon removal with agronomic benefits.

Terrestrial enhanced weathering (EW) of silicate rocks, such as crushed basalt, on farmlands is a promising scalable atmospheric carbon dioxide removal (CDR) strategy that urgently requires performance assessment with commercial farming practices. We report findings from a large-scale replicated EW field trial across a typical maize-soybean rotation on an experimental farm in the heart of the United Sates Corn Belt over 4 y (2016 to 2020). We show an average combined loss of major cations (Ca and Mg) from crushed basalt applied each fall over 4 y (50 t ha y) gave a conservative time-integrated cumulative CDR potential of 10.

Behavior and Fate of Chromium and Carbon during Fe(II)-Induced Transformation of Ferrihydrite Organominerals.

The mobility of chromium (Cr) is controlled by minerals, especially iron (oxyhydr)oxides. The influence of organic carbon (OC) on the mobility and fate of Cr(VI) during Fe(II)-induced transformation of iron (oxyhydr)oxide, however, is still unclear. We investigate how low-weight carboxyl-rich OC influences the transformation of ferrihydrite (Fh) and controls the mobility of Cr(VI/III) in reducing environments and how Cr influences the formation of secondary Fe minerals and the stabilization of OC.

Assessing soil system changes under climate-smart agriculture via farmers' observations and conventional soil testing.

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 terracing under an agroforestry system on soil health indicators in the East Usambara Mountains of Tanzania. Farmers' observations of soil changes were combined with conventional soil testing to assess the initial impacts of SWC practices relative to conventional non-SWC practice.

Transformations to regenerative food systems-An outline of the FixOurFood project.

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? (2) How can transformations be enabled so that we can achieve a regenerative food system? To answer these questions, FixOurFood will work with diverse stakeholders to change the Yorkshire food system and use the learning to inform change efforts in other parts of the UK and beyond. Our work will focus on shifting trajectories towards regenerative dynamics in three inter-related systems of: healthy eating for young children, hybrid food economies and regenerative farming.

The Role of Extracellular DNA in Microbial Attachment to Oxidized Silicon Surfaces in the Presence of Ca and Na.

Attachment assays of a 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 spectroscopy (SMFS) was used to measure the adsorption of eDNA to silicon surfaces in the presence of different concentrations of sodium and calcium ions.

Farmers' indicators of soil health in the African highlands.

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 their choice of land management and needs to be better understood to improve communication between land managers and other stakeholders in agricultural systems.

A novel permeable reactive biobarrier for ortho-nitrochlorobenzene pollution control in groundwater: Experimental evaluation and kinetic modelling.

Three novel permeable reactive barrier (PRB) materials composed of Cu/Fe with 0.24% and 0.43% (w/w) Cu loadings or Fe supported on wheat straw were prepared (termed materials E, F and G).

Insights into the mechanism of the interference of sulfadiazine on soil microbial community and function.

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 profiles under sulfadiazine (SDZ) exposure and proposed a potential mechanism that SDZ accumulation in soil affected soil organic matter (SOM) cycling.

Technologies to deliver food and climate security through agriculture.

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.

Response of soil bacterial communities to sulfadiazine present in manure: Protection and adaptation mechanisms of extracellular polymeric substances.

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 soil bacterial communities to various dosages of sulfadiazine (SDZ) present in manure, with a special emphasis on the role of EPS.

Potential for large-scale CO removal via enhanced rock weathering with croplands.

Enhanced silicate rock weathering (ERW), deployable with croplands, has potential use for atmospheric carbon dioxide (CO) removal (CDR), which is now necessary to mitigate anthropogenic climate change. ERW also has possible co-benefits for improved food and soil security, and reduced ocean acidification. Here we use an integrated performance modelling approach to make an initial techno-economic assessment for 2050, quantifying how CDR potential and costs vary among nations in relation to business-as-usual energy policies and policies consistent with limiting future warming to 2 degrees Celsius.

Impacts of conservation agriculture on soil structure and hydraulic properties of Malawian agricultural systems.

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 are not well understood. The aim of this study was to assess the impacts of long term (10-12 years) maize-based CA on soil hydraulic conductivity, water retention and pore size distribution.

Increased yield and CO sequestration potential with the C cereal Sorghum bicolor cultivated in basaltic rock dust-amended agricultural soil.

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 potential co-benefits for agriculture, require experimental and field evaluation. Here we report that amending a UK clay-loam agricultural soil with a high loading (10 kg/m ) of relatively coarse-grained crushed basalt significantly increased the yield (21 ± 9.

Prediction of contaminant transport in fractured carbonate aquifer types: a case study of the Permian Magnesian Limestone Group (NE England, UK).

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 protection areas. To show this, we use the dolostones of the Permian Magnesian Limestone aquifer in NE England, where we incorporated such information in a groundwater flow and particle tracking model.

Impact of fertiliser, water table, and warming on celery yield and CO and CH emissions from fenland agricultural peat.

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 which organic matter becomes vulnerable to mineralisation.

Evaluating a novel permeable reactive bio-barrier to remediate PAH-contaminated groundwater.

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 and B were the same apart from their carbon source: A was based on wheat straw and B was based on coconut shell biochar.

Human dissemination of genes and microorganisms in Earth's Critical Zone.

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 processes, affecting the atmosphere, shallow lithosphere, hydrosphere, and biosphere.

Simulating carbon capture by enhanced weathering with croplands: an overview of key processes highlighting areas of future model development.

Enhanced weathering (EW) aims to amplify a natural sink for CO 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 CO into soils and drainage waters. EW could counteract phosphorus limitation and greenhouse gas (GHG) emissions in tropical soils, and soil acidification, a common agricultural problem studied with numerical process models over several decades.