Morrow Plots continue to do their job

URBANA, Ill. — When the Morrow Plots were established 150 years ago at then-Illinois Industrial University, the goal was to provide research-based insights into long-term agricultural practices and their impact on soil and crops.

Those unwavering efforts were recognized during the National Historic Landmark Dedication ceremony of the site on Sept. 12, 1968.

Noting the Morrow Plots started 100 years after the Declaration of Independence, University of Illinois Professor M.B. Russell said during that dedication: “It is now clear that the lesson of the Morrow Plots represents a new kind of declaration of independence — not of political independence, but independence from one of the fears that man has had since the dawn of time, the fear of hunger.”

Connecting the past to the U of I’ future in finding solutions through ongoing agricultural research was the theme at the Morrow Plots 150th anniversary celebration Oct. 28.

The celebration started at the historic plots and concluded with the official opening of the Alma Mater Plots south of campus.

History

The Morrow Plots, named for Professor George E. Morrow, the first dean of agriculture at U of I, were established in 1876 and is the oldest experimental crop site in North America and the second oldest in the world.

The Rothamsted research station in England was established in 1843, but the Morrow Plots do hold the distinction of having the longest-running crop rotation experiment in the world.

According to the university archives, the idea of the plots likely emerged from agricultural chemist Charles Wallace Silver, who visited Rothamsted where wheat research had been ongoing for 40 years.

At the time, scientists debated whether Midwestern soils required fertilizer at all. Some believed crop rotation alone could release sufficient nutrients from the soil. These questions set the stage for the long-term experiments that followed.

Manly Miles was hired as a professor of agriculture in 1875, soon began a long-term corn experiment and proposed experimental plots to university leadership.

Miles’ tenure ended after conflicts with Regent John Milton Gregory, and stewardship of the research passed to George Morrow, agriculture chair.

The experimental design explored various farming methods, such as continuous corn, or rotations like corn and oats, or corn, oats and clover. The plots illustrated the connection between soil health and agricultural output.

Early findings demonstrated that crop rotations — such as corn-oats-clover sequences — were superior to continuous corn in maintaining soil quality and increasing yields. Continuous corn plots often showed lower soil organic matter compared to rotated plots.

Perspective

Andrew Margenot, director of the Morrow Plots and Alma Mater Plots and U of I Department of Crop Sciences professor in the College of Agricultural, Consumer and Environmental Sciences, provided a historic perspective during the 150th celebration.

“What has changed since 1876? 1876 was post-Antebellum, post-U.S. Civil War. There’s no more prairie left to plow, and researchers knew this, the government knew this, and there’s a lot of concern about ‘we can’t just keep on burning new prairie,’” Margenot said.

“We knew that by the 1850s, after cropping for four or five years, yields of corn would sag from about 80 bushels to about 20 bushels. The unfertilized corn-on-corn plots today still yield us 20 bushels per acre of corn.

“People knew that we had to do better. There were no clear answers on how to do better. How can we keep corn yields from sagging following that initial flush of fertility by converting prairies to cropland? There were no answers.

“There were all kinds of theories, like plants will just make their own fertility. That was the official USDA position in 1880, and there were some scientists who were responsible for these treatments here that took issue with that.

“One of whom was Dr. Cyril Hopkins. His book, ‘The Farm That Won’t Wear Out,’ is the motivation for the Morrow Plots.

“The question was simple. How does the farm not wear out? How can you keep on raising profitable crops for 200, 300 years? So, from the very beginning, a lot of the intent of this was not simply recommendations for the land-grant mission, but it was much more farther reaching.”

In 1904, researchers began conducting sub-treatments of fertility, a point of contention at the time.

“Some people thought that fertility would just simply happen, not unlike the adage in the Great Dust Bowl that ‘rain follows the plow,’ ‘fertility follows the crop,’” Margenot said.

“We know now that these were incorrect, and it’s easy for us to maybe poke fun at those ideas, but in 1876 through 1920, there was a very vigorous debate on how exactly do we maintain yields. Do fertilizers work? Does manure work?

“If those questions seem obvious in their answers, it’s because the Morrow Plots did her job. She proved through the last 150 years that, yes, in fact, crop rotation benefits yields, so do hybrids, and so do inputs of nutrients and organic matter, be it through manure or phosphate rock, or inputs the fertilizer.

“I think that’s a nice lesson for us today to think about the kinds of questions that the land-grant is uniquely positioned to tackle because of the risk and the contentiousness of the science.

“What are the questions today for the next 150 years that we should think about addressing as a community, as a land-grant, and her stakeholders?

“The questions that were, like in 1876, quite contentious on how to be more sustainable. Again, the farm that won’t wear out — and this is not just biophysical, it’s also economical. In the past few years, I think there’s been this attenuation of a focus on the economic sustainability of agriculture in Illinois and in the greater U.S.”

Plot Tour

Today’s Morrow Plots are divided into three sections of different crop rotations. The northern one-third has been in continuous corn for 150 years.

A two-year rotation is featured in the middle section. It began as a corn-oats rotation and was switched to a corn-soybean rotation in 1968 to mirror the change in farming practices at the time.

The southern one-third of the plots is in a three-year rotation of corn, oats and alfalfa. This preserves one of the original rotations implemented by Morrow. The plot is alfalfa this year, had two cuttings this summer and will be in corn next year.

Margenot pointed out the “marked accentuated differences” in the corn’s height on the continuous corn plots.

“That is a reflection of the eight subplots within that northern third. Each of these thirds are split north, south, as one half, and then east to west into four sections for eight subplots. These have been assigned three treatments of fertility — unfertilized, fertilizer du jour and manure,” he said.

“The very tall corn that’s in the back is the treatment of the fertilizer of the day, the du jour. In 1904, when that began with Dr. Hopkins, that was steamed bone meal. Bone meal from the bison herds would be railed back to the eastern states, steamed, and would be ground up and applied as a source of nitrogen and phosphorus. That was then accompanied with limestone and with phosphate rock.

“Today, we don’t use bison bones. We use urea, potassium as potash and triple super phosphate. These are inputs that no one could even dream of. This is pre-Haber-Bosch’s discovery of synthetic nitrogen in 1915 and 1876 when the Morrow Plots starts.

“The corn on the very northern edge is unfertilized, and it’s shorter than the corn on the southern side where manure was applied. We’ve kept these rates of manure historically the same, and we know now with modern hybrids, it’s not enough to keep up. That’s why the manured corn’s a little bit shorter. That will be changed next year for phase six of these plots. We’re in phase five currently.

“The mere effect of rotating crops, an ecological approach to crop production, that alone can more than triple corn yields. Of course, rotating and fertilizing gives us the highest yields.

“By the data, we’re talking about 20 bushels per acre for corn-on-corn unfertilized, all the way up to 320 bushels per acre in a three-way crop rotation with inputs of potash, urea and phosphorous.

“It seems obvious to us that rotation and fertilizer can benefit yields, but in 1876 that was not really understood. The Morrow Plots has done a good job if that answer seems obvious.”