riparian rap

Soil & Water: Agriculture and the Life Expectancy of Our Natural Resources

Editor’s Note: This post was written by Little River’s new Research Assistant Brooke Hagarty.  Brooke is a Masters student in Forestry at SIU. She also received her B.S. in Forest Hydrology, with a minor in Soil Science, from SIU. Her background includes being a Nature Instructor and Camp Counselor at the local Camp Ondessonk, and a Graduate Teaching Assistant at SIU. Her love of science, nature, and teaching help her fit right in at LRRD, conducting research and speaking to clients about how our river models can help improve their teaching and research.

At a Universities Council on Water Resources (UCOWR) seminar on Southern Illinois University’s Carbondale campus last week, Dr. Richard Cruse gave a presentation titled “Soil and Water: Resources with Decreasing Life Expectancy?” The presentation was eye opening; I am happy to have attended.


tractor farming and soil tilling


Dr. Richard Cruse is the director of the Iowa Water Center, and a Professor of Agronomy at Iowa State University.  He has a heavy background in agriculture, and gave an effective speech on how we are degrading our resources at an alarming rate, in turn threatening food and water security.

There were a lot of numbers and predictions in the seminar, and some of them really stuck out.  He gave some daunting figures for the increase of meat production (mostly cattle) necessary to feed the growing world population and the growth of the middle class.  Predictions estimate that by 2030, 3 billion people will move from the lower to the middle class.  Cruse said that to fulfill the meat demand of the increased middle class, an additional 1 million cattle must be harvested per day.  With increased meat production, there must be increased corn production to feed the livestock.  The more corn production, the more water we use and soil we deplete, as already observed worldwide with the depletion of aquifer levels and farmable soil.


Currently, Cruse and his colleagues are estimating daily soil loss through the entire state of Iowa using LiDAR data.  Cruse said soil formation occurs at an approximate average of 0.5 tons/ac/year. By averaging the LiDAR data across the state, they found that 5.7 tons/ac/year of soil are lost.  That means the amount of soil lost is an order of magnitude greater than the amount of soil produced in a year, which increases the costs of soil erosion. By losing the topsoil from the field, nutrient application must increase to sustain crop productivity, which leads to a spiral of detrimental effects in our waterways.


I think my favorite part of the seminar was when Cruse talked about “ownership by convenience.” He said if you ask a farmer if it would be okay to dump a bag of trash on their land, you would expect the farmer to say no, that is their soil. But if you then ask the farmer, “So when the soil erodes from your land and pollutes my waterway, then is that still your soil?” you can expect the farmer to fall silent. At Little River, we promote teaching concepts such as these with our stream tables.

They demonstrate river morphology phenomena that cannot be easily observed in the field. This is one of the many advantages to viewing fluvial processes in the compressed temporal and spatial scales of the Emriver models. In addition to education, the UN also provides some solutions to what can be done, including improving technologies and using less water to produce more nutritious food for the world. In recent years, there has been a move toward employing more regenerative farming techniques such as no-till.

As the world population grows, our knowledge of and proper management practices for natural resources must grow too. It is crucial that we teach people how to sustainably manage water and soil and how natural systems such as rivers work in order to increase the life expectancy of our resources.

                                        emriver em2 stream table demonstration


Several agencies and organizations in Vermont use the Emriver models to teach landowners and policy makers about sound natural resources management.