Tillage and cover cropping effects on soil properties and crop production in Illinois

Authors: DOZIER, IVAN - University Of Illinois; BEHNKE, GEVAN - University Of Illinois; Davis, Adam; NAFZIGER, EMERSON - University Of Illinois; VILLAMIL, MARIA - University Of Illinois

Submitted to: Soil and Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/19/2016
Publication Date: 5/25/2017
Citation: Dozier, I.A., Behnke, G.D., Davis, A.S., Nafziger, E.D., Villamil, M.B. 2017. Tillage and cover cropping effects on soil properties and crop production in Illinois. Soil and Tillage Research. 109(4):1-10.

Interpretive Summary: The current surge of interest in cover crops(CC) among farmers is fueled by the many ecosystem services that CC can provide, including benefits to soil properties, weed management, nutrient retention and crop yields. There is much variability in cover crop performance and service delivery, however. Many of the claims of cover crop benefits still have only limited support in many production areas, including Illinois. In order to assess the short-term impact of CC on soil properties and crop yields, we conducted a three year field study in Savoy, IL, in which five sets of CC were integrated into a corn-soybean rotation under no-till and chisel plow systems. Studied soil properties included bulk density, water aggregate stability, and penetration resistance, as well as chemical properties of soil organic matter, total carbon stocks, pH, plant available nitrogen, available phosphorus, and exchangeable potassium. Tillage increased the level of soil organic matter and the availability of Potassium within our systems yet significantly decreased the yield of soybeans by 245 kg/ha. Compared to winter fallows, crop yields and soil attributes under corn-soybean rotations that included CC 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 CC in the corn soybean rotation did not affect cash crop yields in either till or no-till systems. Our results show that cereal rye is the most promising CC to be used as an N scavenger in corn soybean rotations under the state’s fluctuating environmental conditions.

Technical Abstract: Cover crops (CCs) have been heralded for their potential to improve soil properties, retain nutrients in the field, and increase subsequent crop yields yet support for these claims within the state of Illinois remains limited. We assessed the effects of integrating five sets of CCs into a corn-soybean [Zea mays L. – Glycine max (L.) Merr.] rotation under no-till and chisel till systems compared with fallow controls on soil attributes and crop yields after one complete rotation cycle. The experimental layout was a split split-block where whole plot treatments (P, phase of the rotation; and Y, year) had a Latin square design and sub plot treatments of tillage (T: NT, no-till vs. Till, chisel till) were further split into sub-subplot treatments of CC rotations (Rcc). Crop yields, CC stand counts in late fall, and spring biomass samples were taken from actively growing CCs each year. Studied soil attributes included bulk density (BD), water aggregate stability (WAS), and penetration resistance (PR), as well as chemical properties of soil organic matter (SOM), total carbon stocks (TCs), pH, plant available nitrogen (TIN, NO3-N and NH4-N), available phosphorus (Pa), and exchangeable potassium (K). Tillage increased the level of SOM and the availability of K within our systems yet significantly decreased the yield of soybeans by 245 kg/ha. Compared to winter fallows, crop yields and 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 no-till systems. Our results show that cereal rye is the most promising CC to be used as N scavenger in corn soybean rotations under the state’s fluctuating environmental conditions.