Soil organic carbon increases crop yield but can’t help with extreme drought
Colorado State University
In cases of extreme drought, soil organic carbon does not improve crop yields, Colorado State University research has found. The finding contradicts the commonly held belief that soil organic carbon benefits yield the most during drought.
The study by scientists in CSU’s College of Agricultural Sciences and Warner College of Natural Resources found that soil organic carbon benefits crops the most during moderate water supply conditions. The paper was published in May in Global Change Biology.
“People often say, ‘Soil organic carbon benefits crops, especially under drought.’ But this is a series of connections that’s not been closely examined," said first author Alison King, who conducted the research as a research scientist at CSU and continued the work at the University of Maine. “In this study, we see that soil organic carbon does benefit crops under drought, but the ‘especially’ applies to ideal growing conditions; this is where we see the greatest benefit for crop yields from increasing soil organic carbon.”
Soil organic carbon increases the capacity of soil to store water, but when water is too scarce, the extra storage capacity can’t benefit the plant.
“There needs to be some water in the soil for the plants to see benefits from improved soil organic carbon,” said co-author Nathan Mueller, an associate professor in the departments of Ecosystem Science and Sustainability and Soil and Crop Sciences. “This matters for how we communicate the value of soil organic carbon to farmers. The benefits are real, and you don’t need an extreme drought to see them. And because moderate years are more common than extreme ones, these production gains accumulate over time.”
The researchers examined corn, soybeans and spring wheat – three critically important rainfed crops that span a large range of weather and soil conditions across the country. They used decades of county-level crop yield records from the U.S. Department of Agriculture along with daily soil moisture and atmospheric water demand data to develop models. The models determine how sensitive crops are to different weather conditions and how soil organic carbon affects this relationship. They found that soil organic carbon increases yields overall and makes them more stable from year to year.
Mueller said the study, “Soil Organic Carbon Improves Crop Yield and Yield Resilience,” is the first to quantify potential gains in crop resilience due to soil organic carbon at a national scale.
Journal
Global Change Biology
Article Title
Soil Organic Carbon Improves Crop Yield and Yield Resilience
No comments:
Post a Comment