When discussing negative impacts on the environment, we might think of fossil fuels or meat production – but bread? Yes, like virtually any other kind of production, that innocent-looking loaf makes its mark. And with 12 million loaves a year sold in the United Kingdom, the greenhouse gases add up.
That’s what spurred a team of interdisciplinary researchers from the University of Sheffield’s Grantham Centre for Sustainable Futures to study the entire supply chain to find out where the most damage is done. Their findings were published February 27 in the journal Nature Plants.
They looked at each field-to-retailer step along the way, from growing and harvesting the wheat, milling the grain and producing the flour to baking the bread, packaging and distribution. Perhaps not surprisingly, the biggest culprit by far – responsible for a whopping 43 percent of greenhouse gases expelled throughout the process – was ammonium nitrate fertilizer.
“We found in every loaf there is embodied global warming resulting from the fertilizer applied to farmers’ fields to increase their wheat harvest,” said study leader Dr. Liam Goucher, N8 Agrifood Research Fellow from the University of Sheffield. “This arises from the large amount of energy needed to make the fertilizer and from nitrous oxide gas released when it is degraded in the soil.”
The research asks some hard questions. Fertilizer use brings down the cost of growing crops – but at what actual cost?
As Professor Peter Horton FRS and a corresponding author of the study pointed out, “High agricultural productivity – necessary for profit for farmers, agribusinesses and food retailers, whilst also keeping prices low for consumers – currently requires high levels of application of relatively cheap fertilizers.”
There are some possible solutions, through “improved agronomic practices,” said co-author Professor Duncan Cameron, co-director of the P3 Centre for Translational Plant and Soil Science. “These harness the best of organic farming combined with new technologies to better monitor the nutritional status of soils and plants and to recycle waste, and with the promise of new wheat varieties able to utilize soil nitrogen more efficiently.”
Author Shel Horowitz told Earth.com that we collectively hold the answer. ““In my tenth book, Guerrilla Marketing to Heal the World, and in my speaking, I show the impact of consumer choices on showing businesses how they HAVE to be part of the change – and how these businesses can profit when they go beyond mere “sustainability” (keeping things the same) to “regenerativity” (making things better).”
By David Searls, Earth.com Staff Writer
Source: University of Sheffield, Nature Plants