Cereal Rye (Secale Cereale L.) Cover Crop Impacts on Soil Physical and Chemical Properties in Southeastern Indiana.

Cover crops are becoming a more popular conservation practice to protect and improve soils across the Midwest during the winter fallow season in a typical corn-soybean (Zea mays L. – Glycine max L. Merr.) rotation. A sixteen hectare field site was established at the Southeastern Purdue Agricultural Center (SEPAC) near Butlerville Indiana as part of the Corn Based Cropping Systems Coordinated Agricultural Project (CSCAP), a collaborative project including ten land grant universities across the Midwest. One of the main goals of the project was to evaluate the effects of different management practices on the resiliency of corn based cropping systems to climate stresses. Treatments were divided in a split plot design and included corn and soybeans alternating yearly with or without a cereal rye cover crop. After four years, wet soil aggregate mean weight diameter in the 0-10 cm depth was significantly greater under the cereal rye treatments (3.4 mm) compared to the no cover treatments (2.2 mm). At the 10-20 cm depth mean weight diameters averaged 2.7 mm and 2.1 mm in the cereal rye and no cover treatments, respectively.  There were no significant differences in aggregation in the 20-40 cm and 40-60 cm depths. Soil organic carbon, total soil nitrogen, and soil bulk density were measured at 0-10, 10-20, 20-40, and 40-60 cm depths and showed no significant differences between the cover treatments. Soil volumetric water content was measured using the intact core method at 0, -4.9, -9.8, -33, and -1500 kPa and no significant differences were found among cover crop and cash crop treatments. An increase in water stable aggregates can help to protect the soil against erosion and reduce surface crusting potential and could potentially be an indicator of other soil property improvements that may accrue over a longer time.