UNL research shows high-input agriculture systems are better

For University of Nebraska-Lincoln researchers Ken Cassman and Patricio Grassini, 2012 is already turning out to be a pretty good year.

The UNL agronomists proved false a popular belief that high-input agricultural systems are harmful to the environment.

The pair co-authored an article published in the Jan. 10 "Proceedings of the National Academy of Sciences."

Cassman holds the Robert B. Daugherty Professorship at UNL, and Grassini is a former Fulbright Scholar who has researched crop systems in Argentina as well as in the Midwest.

The article is titled "High-yield maize with large net energy yield and small global warming intensity," and can be viewed on the "Proceedings of the National Academy of Sciences" website.

Cassman and Grassini's research shows that Nebraska corn grown by an irrigated system contributes to efficient energy, water and fertilizer usage.

The fear of greenhouse gases and the desire to "go green" by taking measures to benefit and protect the environment are prevalent sentiments in American culture.

Cassman said all production industries are being faced with the challenge of improving their impact on the environment, and this extends past agriculture into other sectors like transportation and energy.

It was previously believed that using high-input agricultural systems to produce crops would also produce more greenhouse gases and was dangerous for the environment.

Cassman and Grassini say that is not true.

According to their research, high-input farming is the most efficient way to produce crops because it results in the highest crop yield.

"There's an increased demand for food in the world," Grassini said. "It's possible to achieve increased food production with less input."

Although rain-fed agriculture uses less fossil fuels and produces fewer greenhouse gases than high-input systems, Cassman and Grassini discovered that high-input agriculture comes out on top when comparing the per-unit energy yield and gas emissions.

For the first time, according to Grassini, UNL research on this subject involved primary data collected by the researchers themselves, rather than secondary data obtained from the Department of Agriculture.

Grassini said that 377 fields were tested from 2005 to 2007. The data used for Cassman and Grassini's research came from farmers who were required to report their practices.

The factors examined include the amount of water and fertilizer used, the type of tillage system used in the fields and whether the irrigation system was pivot or surface. According to Cassman, this information was entered into a database, which then showed the researchers what factors affect yield the most.

"Each of these (field) owners defined priorities according to their own interests," Grassini said.  

Cassman said the whole purpose of the team's research lies in evaluating the production side of an agricultural system and weighing it against the impact it has upon the environment.

"There's always trade-offs," he said.  "There's no perfect system."

Each of the field owners was mailed a more in-depth survey and 123 field owners responded. Cassman said he determined the average input of the 123 responding fields to be comparable to the average of the 377 total fields, indicating that the responding fields are representative of the entire group.

Cassman said with rain-fed agriculture systems the yield varies every year depending on nature, but with an irrigated system farmers know what their yield will be, and how to maximize it, because there's little variation.

"In our view, there's a (trend) throughout the world related to questions about how best to allow economic growth to proceed for all of humanity and still protect the environment," Cassman said.

It is important to balance the environment with energy, agriculture and transportation, he said.

"We need those things," Cassman said. "But we have to be smart about how we get them."

marenwestra@dailynebraskan.com