A briefing note from our team sets out a model for sustainable agriculture. Their model combines lessons from history with biotechnology to redesign sustainability in intensive agriculture.
Speaking at COP21 in Paris our experts laid out an impending soil loss disaster. Nearly 33% of the world’s arable land has been lost to erosion or pollution in the last 40 years. Vital action must be taken to prevent devastating knock-on effects. Now they have released a briefing note that addresses this issue.
Global food production will likely have to increase over the coming decades. But this will be increasingly difficult as we feel the effects of climate change. Current intensive agriculture is unsustainable. So a different path is needed.
Sustainable intensification is heralded as the saviour of agriculture – but what does it mean in practice?
Our briefing note sets out a model that combines the lessons of history with biotechnology to redesign agriculture.
A sustainable model for intensive agriculture: Grantham Centre briefing note by Profs Duncan Cameron, Colin Osborne and Peter Horton.
Duncan Cameron, Professor of Plant and Soil Biology at the University of Sheffield, said: “Soil is lost rapidly but replaced over millennia and this represents one of the greatest global threats for agriculture.
“Erosion rates from ploughed fields average 10-100 times greater than rates of soil formation and nearly 33% of the world’s arable land has been lost to erosion or pollution in the last 40 years.
“This is catastrophic when you think that it takes about 500 years to form 2.5 cm of topsoil under normal agricultural conditions. A sustainable model for intensive agriculture could combine the lessons of history with the benefits of modern biotechnology.”
Colin Osborne, Professor of Plant Biology at the University of Sheffield and our Associate Director added: “Historically, good soil management was supplemented by the collection and application of ‘night soil’, which is human excrement – a practice that continued into the 20th century.
“In a historical example of the circular economy, this closed the nutrient loop, recycling organic nitrogen and phosphorus back into soil.
“A sustainable soil-centric reengineering of the agricultural system would reduce the need for fertiliser inputs and pesticide application, and require less irrigation, thus contributing towards safeguarding finite natural resources.”
Managing soil by direct manure application, rotating annual and cover crops, and practising no-till agriculture (not cultivating and preparing the land). Conservation agriculture restores soil organic matter, structure, water-holding capacity and nutrients, and averts soil loss while benefiting crops.
Using biotechnology to wean crops off the artificial world we have created for them, enabling plants to initiate and sustain symbioses (close interactions) with soil microbes. Symbioses allow crops to exploit microbial biology to tap into soil organic nutrient reserves, and prime plants to better defend themselves against pests and diseases.
Recycling nutrients from sewage in a modern example of the circular economy. Inorganic fertilizers could be manufactured from human sewage in biorefineries operating at industrial or local scales. A number of technical challenges impede the immediate adoption of this idea, but these can readily be addressed through research.
Professor Peter Horton, Emeritus Professor of Biochemistry and our Associate Director said: “In order to facilitate such a wholesale redesign of the agricultural system, we need to assess the potential scientific, economic, cultural and political impediments to this happening, and resolve the potential benefits of this redesign for sustainability.
“In doing so, we could reduce our dependence on energy-intensive and non-renewable inorganic fertiliser, reduce fertiliser pollution of watercourses, and create a soil fit for future generations.
“Of course, no one model equally fits all problems. Different agricultural scenarios such as varying geography, climate or crop might benefit from our approach more than others. And any redesign of the agricultural system needs to be sufficiently flexible to accommodate this.”
Grantham Centre researchers come from across disciplines at the University of Sheffield to work on soil. As a result we have a range of experts from science to social science researching soil. Find out more Soil research at the Grantham Centre.
Access a PDF of the briefing note: A sustainable model for intensive agriculture: Grantham Centre briefing note.