The Morrow Plots, located at the University of Illinois Urbana-Champaign, are the oldest continuous experimental crop fields in the United States. Established in 1876, these fields serve as a living agricultural laboratory, providing data for over a century. They offer insights into long-term agricultural practices and their effects on soil and crops.
Origin and Early Goals
Established in 1876, a period when agricultural concerns about soil depletion were growing, Professor George E. Morrow, the first dean of agriculture at the University of Illinois, developed these plots, expanding them to ten half-acre sections by 1879. The primary goal was to conduct long-term studies on how different crop rotations and fertilization practices impacted soil health, productivity, and crop yields.
The experimental design explored various farming methods, such as continuous corn, or rotations like corn and oats, or corn, oats, and clover. This long-term perspective was supported by the Hatch Act of 1887, which established agricultural experiment stations and provided federal funding for scientific research in agriculture. Data collection began in 1888, providing an uninterrupted record of planting, treatment, and yield.
Enduring Scientific Contributions
Over decades, the Morrow Plots have yielded scientific insights into sustainable agriculture. Early findings demonstrated that crop rotation, such as corn-oats-clover sequences, was superior to continuous corn in maintaining soil quality and increasing yields. Continuous corn plots often showed lower soil organic matter compared to rotated plots.
The experiments also revealed the impact of different fertilization methods on soil characteristics and crop productivity. Studies compared plots receiving manure, synthetic fertilizers, or no amendments. These comparisons showed how manure applications improved soil organic matter, while synthetic fertilizers restored productivity to depleted soil.
The plots illustrated the connection between soil health and agricultural output. Research indicated that corn following soybeans generally out-yielded continuous corn, even with higher fertility inputs. This long-term data has been instrumental in understanding soil nutrient depletion and the benefits of diverse cropping systems for maintaining fertility and soil health.
Modern Impact and Preservation
The Morrow Plots continue to serve as an outdoor laboratory for contemporary agricultural research. They support studies addressing modern challenges like climate change, investigating how long-term soil management affects carbon sequestration and soil bacteria. Researchers also use the plots to investigate advanced soil science techniques and evolving farming practices, including changes in tillage.
The plots were designated a National Historic Landmark on May 23, 1968, recognizing their historical and scientific value. Today, only three of the original ten plots remain, each roughly one-fifth of an acre, situated centrally on the University of Illinois campus. They serve as an educational site, showcasing long-term scientific inquiry in agriculture to students and the public.