Double pressure makes soil microbes "collapse"

Soil is the home of various microbial communities, which circulate nutrients, support farming and capture carbon-an important "service" for mitigating climate change
.

A new study led by Jane Lucas, a community ecologist at the Cary Ecosystem Research Institute in the United States, investigated the interaction of rising temperatures and a common livestock antibiotic on soil microbes
.

This research has now been published online and will be published in "Soil Biology and Biochemistry" soon
.

Lucas said: "Most soil health research only examines one stressor
at a time .

Monensin was chosen because it is a common antibiotic and its use in cattle farms is expanding
.

The research team collected grassland soil samples from protected areas in northern Idaho where there were no grazing livestock and treated them with high, low or no dose antibiotics
.

For each treatment method, the research team monitored soil respiration, acidity, microbial community composition and function, carbon and nitrogen cycles, and the interaction between microorganisms
.

They found that with the increase in temperature and the addition of antibiotics, the bacteria "collapse", allowing the fungus to dominate and homogenize, resulting in a double reduction in the total number and diversity of microorganisms
.

Lucas said: "In both low-dose and high-dose additions, we have seen real changes
in the soil microbial community .

Essentially, when microorganisms are in an environment with high temperature and high antibiotic content, they must "work" harder to survive
.

As soil microorganisms work harder but inefficiently process carbon, less and less carbon is converted into a stable organic form and becomes trapped in the soil
.
On the contrary, more and more carbon dioxide is released into the atmosphere as a gas
.
This effect may convert an important carbon sink into a carbon source, exacerbating the impact of climate change
.

Michael Strickland, Associate Professor of the Department of Soil and Water Systems at the University of Idaho, said: "The power of environmental change does not come out in isolation
.
Our results show that heating alone, antibiotics alone, and heating and antibiotics together have different effects on soil microbial communities.

These findings emphasize the importance of testing multiple stressors at the same time to gain a more comprehensive understanding of how the soil and its basic functions change
.
"

Lucas concluded: “Agriculture, environment, and public health are inseparable
.
Understanding how multiple stressors shape soil microbes is essential to support soil health in the face of global change
.
If you don’t manage to achieve interactive effects, soil carbon storage capacity and crop yields, etc.
May be adversely affected
.
In addition to broader climate mitigation measures, limiting the investment of antibiotics in the environment also helps to protect the soil
.
” (Source: Wang Fang, China Science News)

Related paper information: https://doi.
org/10.
1016/j.
soilbio.
2021.
108437