A study co-authored by scientists at UNDO has found that enhanced rock weathering contributed to a 9.3-20.5% higher crop yield and suggests increased crop resilience to future climate challenges.
Rock weathering is a nature-based carbon dioxide removal process that accelerates natural weathering.
The study’s results show significantly higher first year crop yields, improved soil pH and higher nutrient uptake.
The results from the ongoing trial’s first year demonstrate that the crop yield was on average 15% higher (9.3% and 20.5% between ploughed and direct drill amended plots respectively) across two different cultivation techniques.
The trial results also showed a stabilising effect on the soil pH, with the soil pH being on average 0.2 and 0.29 pH units higher in the basalt-amended plots, compared to the control plots.
This change is a result of alkaline products generated as the rock minerals dissolve, the scientists said.
The effect of silicate mineral dissolution on the soil pH could represent an attractive agronomic benefit for farmers as an elevated soil pH allows crops to access more nutrients in the soil.
Head of science and research at UNDO and co-author of the paper, Dr XinRan Liu, said:
“Nutrient limitations in agricultural soils are a major concern for farmers in relation to sustaining and increasing crop yields.
“This latest study highlights how the spreading of basalt rock on farmland can lead to higher crop yields and can be effective in a temperate climate.
“This research demonstrates the potential for enhanced rock weathering to contribute to improved farmer livelihoods and food production, whilst also removing CO2 from the atmosphere.”
Basalt rock
Basalt rock is rich in minerals that slowly release nutrients during dissolution and these nutrients act as a natural soil amendment and are essential for plant growth, scientists say.
The study found higher nutrient concentrations in the crops grown in the basalt-amended soil, including tissue calcium, grain and tissue potassium, suggesting that ERW can boost nutrient availability for plants and, as a result, may improve crop yield.
Taking account of the “unusually dry” growing season conditions in 2022, these findings indicate that basalt amendment could enhance productivity and crop yields.
This contributes to more sustainable and resilient food production systems in the face of future changes in growing season weather as a result of global warming, the study concluded.
Prof David Manning of Newcastle University, who co-authored the paper, said: “The results of this trial give further scientific credibility for enhanced rock weathering and greatly improve its value proposition to farmers.
“Newcastle University is pleased to partner with UNDO. Our joint research into the co-benefits for farmers of basalt amendment is helping to pave the way for the widespread adoption of enhanced rock weathering in the agricultural community.”
The trial results also show no additional toxic elements taken up by crops in the plots where basalt had been spread.
There was no negative impact on the natural environment in this trial, which indicates the food produced from it is safe for consumption.
UNDO’s basalt has been approved for use in organic farming systems by respected certification bodies such as the Soil Association.
