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Addressing soil nutrient degradation and global warming requires novel solutions. Enhanced weathering using crushed basalt rock may offer a partial solution, through a combined approach of sequestering carbon dioxide and improving agronomic conditions. This study examines the short-term effects of basalt amendment on spring oat (Avena sativa L.) during the 2022 growing season in NE England. The experimental design consisted of four blocks with control and basalt-amended plots, and two cultivation types within each treatment, laid out in a split plot design. Basalt (18.86 tonnes ha−1) was incorporated during seeding. Tissue, grain and soil samples were collected for yield, nutrient, and pH analysis. Basalt amendment led to significantly higher yields, averaging 20.5% and 9.3% increases in direct drill and ploughed plots, respectively. Soil pH was significantly higher 256 days after application across cultivation types (direct drill: on average 6.47 vs. 6.76 and ploughed: on average 6.69 vs. 6.89, for control and basalt amended plots, respectively), likely due to rapidly dissolving minerals. Indications of growing season differences in soil pH are observed through reduced manganese and iron uptake in amended crops. Higher grain and tissue potassium, and tissue calcium uptake were observed in basalt-amended crops. In contrast, no accumulation of potentially toxic elements was detected in the grain, indicating that crops grown using this crushed basalt rock are safe for consumption. This study suggests that agronomic benefits following crushed basalt rock applications are attainable in regions with temperate climate and similar soil conditions. These findings offer valuable insights for producers in temperate climates who are considering using such amendments, demonstrating the potential for improved crop yields and environmental benefits while ensuring crop safety.

Enhanced weathering of silicate rock is a promising natural carbon dioxide removal technology, both due to its scalability and associated agronomical benefits. During silicate rock weathering, dissolved carbon dioxide in the form of carbonic acid, reacts with rock minerals to form stable soil pore water bicarbonate or soil calcium carbonate. The carbon dioxide removal potential of enhanced weathering has been successfully demonstrated in short-term lab and mesocosm studies. Due to the transient nature of bicarbonate in the aqueous soil solution, in-field quantification of the carbon dioxide sequestered is tedious, labour-intense and poorly scalable for the verification of carbon credits. Various methods have been suggested in order to quantify the amount of carbon dioxide sequestered through rock weathering. This quantification is essential for verification bodies to award carbon credits. Although various methods have been proposed to demonstrate that in-field weathering is occurring, there is still no consensus for a scalable, profitable solution. In recent years, an increasing number of field trials have seen the light of day. However, large uncertainties about in-field weathering rates and the influence of natural environmental variability, such as drought and vaying temperatures, still exist. In this study we focus on two proxies affected by the weathering process, namely pH and EC. We compare field measurements of pH and EC from both in-situ sensors and extracted soil pore water with model predictions from a 1D-reactive transport model. The data originates from an ongoing field trial on an acidic, clay rich soil used for grassland pasture in central Scotland. Such in-field proxy measurements may provide information to help boost confidence in model predictions.

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/m2) of relatively coarse‐grained crushed basalt significantly increased the yield (21 ± 9.4%, SE ) of the important C4 cereal Sorghum bicolor under controlled environmental conditions, without accumulation of potentially toxic trace elements in the seeds. Yield increases resulted from the basalt treatment after 120 days without P‐ and K‐fertilizer addition. Shoot silicon concentrations also increased significantly (26 ± 5.4%, SE ), with potential benefits for crop resistance to biotic and abiotic stress. Elemental budgets indicate substantial release of base cations important for inorganic carbon removal and their accumulation mainly in the soil exchangeable pools. Geochemical reactive transport modelling, constrained by elemental budgets, indicated CO2 sequestration rates of 2–4 t CO2/ha, 1–5 years after a single application of basaltic rock dust, including via newly formed soil carbonate minerals whose long‐term fate requires assessment through field trials. This represents an approximately fourfold increase in carbon capture compared to control plant–soil systems without basalt. Our results build support for ERW deployment as a CDR technique compatible with spreading basalt powder on acidic loamy soils common across millions of hectares of western European and North American agriculture.

The magnitude of future climate change could be moderated by immediately reducing the amount of CO2 entering the atmosphere as a result of energy generation and by adopting strategies that actively remove CO2 from it. Biogeochemical improvement of soils by adding crushed, fast-reacting silicate rocks to croplands is one such CO2-removal strategy. This approach has the potential to improve crop production, increase protection from pests and diseases, and restore soil fertility and structure. Managed croplands worldwide are already equipped for frequent rock dust additions to soils, making rapid adoption at scale feasible, and the potential benefits could generate financial incentives for widespread adoption in the agricultural sector. However, there are still obstacles to be surmounted. Audited field-scale assessments of the efficacy of CO2 capture are urgently required together with detailed environmental monitoring. A cost-effective way to meet the rock requirements for CO2 removal must be found, possibly involving the recycling of silicate waste materials. Finally, issues of public perception, trust and acceptance must also be addressed. Refereed/Peer-reviewed

In the version of this Perspective originally published, ‘acidification’ was incorrectly spelt as ‘adification’ in Fig. 4. This has now been corrected.