Farming crops with rocks to reduce CO2 and improve global food security

February 19, 2018, University of Sheffield
Credit: SC Department of Agriculture

Farming crops with crushed rocks could help to improve global food security and reduce the amount of CO2 entering the atmosphere, a new study has found.

The pioneering research by scientists at the University of Sheffield together with international colleagues suggests that adding fast-reacting silicate rocks to croplands could capture CO2 and give increased protection from pests and diseases while restoring structure and fertility.

Professor David Beerling, Director of the Leverhulme Centre for Climate Change Mitigation at the University of Sheffield and lead author of the research, said: "Human societies have long known that volcanic plains are fertile, ideal places for growing crops without adverse , but until now there has been little consideration for how adding further rocks to soils might capture carbon.

"This study has transformed how we think about managing our croplands for climate, food and soil security. It helps move the debate forward for an under-researched strategy of CO2 removal from the atmosphere - enhanced rock weathering - and highlights supplementary benefits for food and soils.

"The magnitude of future could be moderated by immediately reducing the amount of CO2 entering the atmosphere as a result of energy generation. Adopting strategies like this new research that actively remove CO2 from it can have a massive impact and be adapted very quickly."

The research, published today (19 February 2018) in Nature Plants, examined the approach which involves amending soils with abundant crushed silicate rocks, like basalt, left over from ancient volcanic eruptions. As these minute rock grains dissolve chemically in soils, they take up and release plant-essential nutrients.

Critically, enhanced rock weathering works together with existing managed croplands. Unlike other carbon removal strategies being considered, it doesn't compete for land used to grow food or increase the demand for freshwater. Other benefits include reducing the usage of agricultural fertilizers and pesticides, lowering the cost of food production, increasing the profitability of farms and reducing the barriers to uptake by the agricultural sector.

Crushed could be applied to any soils, but arable land is the most obvious since it is worked and planted annually. It covers some 14 million square kilometres or 10 per cent of the global land area.

Arable farms already apply crushed rock in the form of limestone to reverse acidification of soils caused by farming practices, including the use of fertilizers. Managed crops, therefore, have the logistical infrastructure such as the road networks and machinery needed to undertake this approach at scale. These considerations could make it straight forward to adopt.

Professor Stephen Long at the University of Illinois Champaign-Urbana, and co-author of the study added: "Our proposal is that changing the type of , and increasing the application rate, would do the same job as applying crushed limestone but help capture CO2 from the atmosphere, storing it in soils and eventually the oceans.

"Global warming is a problem that affects everyone on the planet. Scientists generally have done a poor job of getting across the point that the world must reduce emissions of greenhouse gases from fossil fuels and combine this with strategies for extracting carbon dioxide from the atmosphere to avoid a climate catastrophe."

Professor James Hansen from the Earth Institute at Columbia University and co-author of the work, added: "Strategies for taking CO2 out of the atmosphere are now on the research agenda and we need realistic assessment of these strategies, what they might be able to deliver, and what the challenges are."

Explore further: Win-win strategies for climate and food security

More information: David J. Beerling et al, Farming with crops and rocks to address global climate, food and soil security, Nature Plants (2018). DOI: 10.1038/s41477-018-0108-y

Related Stories

Win-win strategies for climate and food security

October 2, 2017

Climate policies that target agriculture and forests could lead to increased food prices. But reducing deforestation and increasing soil carbon sequestration in agriculture could significantly reduce greenhouse gas emissions ...

Ancient forests stabilized Earth's CO2 and climate

January 23, 2014

UK researchers have identified a biological mechanism that could explain how the Earth's atmospheric carbon dioxide and climate were stabilised over the past 24 million years. When CO2 levels became too low for plants to ...

Video: Developing carbon management solutions

July 20, 2017

Global consumption of fossil fuels is causing atmospheric carbon dioxide and other greenhouse gases to rise to levels that threaten human and environmental sustainability. These gases warm the planet and negatively impact ...

Recommended for you

What happened before the Big Bang?

March 26, 2019

A team of scientists has proposed a powerful new test for inflation, the theory that the universe dramatically expanded in size in a fleeting fraction of a second right after the Big Bang. Their goal is to give insight into ...

Cellular microRNA detection with miRacles

March 26, 2019

MicroRNAs (miRNAs) are short noncoding regulatory RNAs that can repress gene expression post-transcriptionally and are therefore increasingly used as biomarkers of disease. Detecting miRNAs can be arduous and expensive as ...

Can China keep it's climate promises?

March 26, 2019

China can easily meet its Paris climate pledge to peak its greenhouse gas emissions by 2030, but sourcing 20 percent of its energy needs from renewables and nuclear power by that date may be considerably harder, researchers ...

In the Tree of Life, youth has its advantages

March 26, 2019

It's a question that has captivated naturalists for centuries: Why have some groups of organisms enjoyed incredibly diversity—like fish, birds, insects—while others have contained only a few species—like humans.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.