Iowa State University has begun an environmental assessment to determine the amount of carbon in the soil of the land that it and its affiliated organizations own and manage.

"One increasingly recognized method of evaluating land in an environmental context is assessing the soils' carbon content," said Catherine DeLong, a graduate student in agronomy who is working on the study.

"Through this project Iowa State is pairing its historic mission of helping the Iowa farmer, with its expanding global mission of benefiting the environment as a whole, as well as evaluating its global environmental impact," said DeLong.

Carbon plays an important role in the environment. It is the basis of organic matter and the source of the characteristic dark color of Iowa's soils.

"Carbon plays a huge role in the soil," said Lee Burras, Iowa State agronomy professor who is supervising DeLong's study.

"It affects water behavior, plant growth and other life such as worms that we want to live in the soil. Worldwide, carbon content is considered the best indicator of soil quality," said DeLong.

Photosynthesizing plants take in carbon dioxide (CO2), biochemically converting the carbon into the structure of the plant. When the plant dies and decomposes, that carbon becomes part of the soil; potentially, a very stable part.

This process of holding carbon in the soil is known as carbon sequestration and has been increasingly cited as a method to combat global CO2 emissions.

"By sequestering carbon, we are enhancing that piece of the soil," DeLong said.

Carbon and organic matter can be thought of as the 'glue' holding nutrients on the soil surface, which in turn increases water-holding capacity and allows the soil to act as a buffer against drought conditions.

On the other side of the climatic spectrum, a better soil water-holding capacity also will help to diminish nutrient runoff and protect water quality during heavy rains.

Besides improving the soils' fertility in the long term, carbon sequestration has the potential to bring profits through the regulation and sales of carbon credits.

For example, offering entities emitting CO2 a way to offset them by purchasing credits from a farmer whose management practices are sequestering carbon.

The university owns or manages 77 properties in Iowa ranging across 20 major soil associations with land management practices varying from row crops and livestock to forests and pasture.

This variability allows for the analysis of a range of soil carbon dynamics, and increases the understanding of this important property.

The land is used primarily for research, teaching and Extension activities and is located primarily in central Iowa near Ames. The holdings also include a diverse portfolio of gifted farms and outlying research farms owned by local associations.

The study's findings will be released next year.