Farms.com Home   News

Temperatures Are Rising, but Soil is Getting Wetter—Why?

Temperatures Are Rising, but Soil is Getting Wetter—Why?

By Leah Burrows

Soil moisture can determine how quickly a wildfire spreads, how fast a hill turns into a mudslide, and perhaps most importantly, how productive our food systems are. As temperatures rise due to human-caused climate change, some researchers are concerned that soils will dry. However, between 2011 to 2020, soil moisture increased across 57% of the United States during summer, the warmest time of year.

Why did soil get wetter even as the planet got hotter?

A recent study from Harvard University researchers has found that precipitation, rather than temperature, overwhelmingly explains soil moisture trends. While it's not surprising that more rain means wetter soil, the research challenges a long-standing assumption that increases in  will lead to drier soils.

The work is published in the journal Nature Water.

"Atmospheric water has often been used as a proxy for drought, but this paper highlights distinctions between the hydroclimate of soils and the temperature and hydroclimate of the atmosphere," said Peter Huybers, Professor of Earth and Planetary Sciences in the Faculty of Arts and Sciences and of Environmental Science and Engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences, and senior author of the paper.

The research team found that drying from increased temperature was largely balanced by CO2 fertilization, which allows plants to use water more efficiently. Both these effects are secondary relative to rainfall and tend to cancel each other out—leaving precipitation as the primary driver of soil moisture.

One challenge in studying soil moisture is a sparsity of data and the frequent disconnect between satellite data and ground level observations. The team compared ground level observations between 2011 and 2020—the short time period during which many soil moisture measurements are available across the United States—with  and found a similar increase in soil moisture.

These findings highlight the importance of improving predictions of long-term changes in precipitation in response to climate change, especially in relation to food production.

"We don't have very accurate measurements of long-term soil moisture, but the consequences of high temperatures for agricultural yields have a lot to do with ," said Lucas Vargas Zeppetello, who was a Fellow at the Harvard University Center for the Environment and is first author of the study. "Plants are generally less sensitive to temperature if they have sufficient water, but in dry conditions they can get in big trouble."

Vargas Zeppetello is now an assistant professor at UC Berkeley.

"Our results suggest that reduced surface soil moisture is far from a foregone conclusion given the  in precipitation trends around the globe," said Huybers. "With uncertainties in the interannual variability of rainfall and uncertainties in predictions of long-term rainfall, it's virtually impossible to predict  in the coming decades."

Click here to see more...

Trending Video

Verbio | Anaerobic Digestion on the Farm Virtual Tour

Video: Verbio | Anaerobic Digestion on the Farm Virtual Tour

VERBIO Vereinigte BioEnergie AG (VERBIO AG), headquartered in Leipzig, Germany, is a leading independent manufacturer of biofuels and bioenergy in Germany and Europe. The company began producing biofuel in 2001 and today has approximately 1,000 employees at its locations in six countries producing biodiesel, bioethanol and renewable natural gas, as well as feed, bio-fertilizers and other highvalue by-products for the nutrition, pharmaceutical and cosmetics industries. The Verbio North America site, located in Nevada, IA, is committed to the principle of sustainability and treats natural resources in a socially responsible and ethical manner. Using the latest technologies developed in-house, the Verbio team is creating sustainable alternatives for a world whose desire is to move away from fossil fuels. Verbio’s business model attempts to ignite change and create platforms where the path to green energy is contagious.