If Europe adopted a style of farming that abstains from plowing after a harvest, local temperatures could drop as much as two degrees Celsius (3.6 degrees Fahrenheit), researchers said on June 23. The reason lies in the color of the soil: untilled land is lighter and reflects sunlight, making the area cooler than it is when dark surfaces are present, according to scientists.
Fields that are plowed also dry out faster. In contrast, untilled land allows moisture to evaporate more slowly and can contribute to cooling. The effects could be particularly noticeable during hot spells, said the findings in the Proceedings of the National Academy of Sciences, a peer-reviewed US journal.
"For heatwave summer days the local cooling effect gained from no-till practice is of the order of 2 degrees Celsius," said the study led by scientists in Switzerland and France.
Researchers found that the unplowed stubble of wheat fields helped reflect 30 percent of incoming sunlight, compared to just 20 percent in plowed fields. Computer models showed that the difference could translate to a difference of two degrees Celsius on hot days, though the effects would stay largely local.
"In other words, if all French farmers were to stop plowing up their fields in summer, the impact on temperatures in Germany would be negligible," said Sonia Seneviratne, professor of land-climate dynamics at the Institute for Atmospheric and Climate Science in Zurich.
Advocates of no-till farming say the practice could bring even more benefits, such as saving water, preventing soil erosion and even curbing global warming. The US Department of Agriculture, in a 2010 report, said the practice could "sequester substantial amounts of carbon" by helping the Earth contain more carbon, thereby cutting greenhouse gas emissions that drive global warming.
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