Tillage and Cover Cropping Effects on Soil Properties and Crop Production in Illinois

Core Ideas Compared corn–soybean rotations with cover crops vs fallows under no‐till or till. Corn–soybean rotations with cereal rye after corn decreased soil NO 3 –N by 42%. Soil attributes and crop yields were generally unaffected by cover crops use. Tillage increased soil organic matter and exchangeable K compared to no‐till. Tillage reduced soybean yields by 245 kg/ha compared to no‐till. Cover crops (CCs) have been heralded for their potential to improve soil properties, retain nutrients in the field, and subsequent crop yields, yet support for these claims within Illinois remains limited. Cover crops were used in corn ( Zea mays L.)–soybean [ Glycine max (L.) Merr.] rotations. We assessed five sets of CCs vs. fallow controls under no‐till (NT) and chisel till (Till) on soil attributes and crop yields, encompassing one complete rotation cycle. The experimental layout was a split split‐block where whole plot treatments (P, rotation phase; and Y, year) had a Latin square design and subplot treatments of tillage (NT vs. Till) were split into sub‐subplot treatments of CC rotations. We measured soil properties, crop yields, CC stand counts in late fall, and spring biomass samples, each year. Tillage increased the level of soil organic matter (SOM) and exchangeable potassium (K) within our systems yet significantly decreased the yield of soybean by 245 kg/ha. Compared to winter fallow, soil attributes under corn–soybean rotations that included CCs did not show any statistically significant change after one cycle of production except increased N scavenging with cereal rye growing after corn harvest. Inclusion of CCs in the corn–soybean rotation did not affect cash crop yields in either till or NT systems. Our results show that cereal rye is the CC with the best potential as an N scavenger in the corn–soybean rotation, but claims of crop yield increases in the short term are not supported.