ABSTRACT
The Morrow Plots at the University of Illinois are the oldest agronomic research fields in America and include the oldest continuous corn plots in the world. This chapter presents data on soil organic carbon (SOC) content in the surface 15 cm of the plots that reflect soil treatments and cropping systems. While SOC levels initially decline under continuous cultivation, proper management can overcome some of the deleterious effects of cultivation. The SOC level of the grass border is higher on the east than on the west. Also, the sampling between the plots in the alleys shows an increase in SOC west to east as does the trend of the average SOC for the plot soil sampling. The plots were established to settle a controversy about depletion of the dark prairie soils. The Morrow Plots are a registered national historic landmark.
