Soil C and N Dynamics for a Corn- Perennial Cover Crop Cropping System.

New corn (Zea mays L.) management systems are needed that enhance soil quality and facilitate sustainable residue harvesting for bioenergy production. The overarching objective of this field study was to test the hypothesis that Kentucky bluegrass (Poa pratensis L.) and tall fescue [Schedonorus arundinaceus (Schreb.)  Dumort. ] perennial cover crops managed with strip tillage and spring burndown are agronomically competitive and can help build soil quality relative to conventionally managed corn cropping systems with residue harvesting. Here we report the impact of the perennial cover crops and strip tillage on soil C- and N dynamics. Soil samples were collected in spring 2014 prior to cover crop establishment and analyzed for Mehlich III extractable nutrients, total C and N to establish baseline values. Fall 2014 samples were analyzed for extractable nutrients and potential mineralizable N (PMN).  Additional soil samples are being collected monthly during the 2015 growing season from within rows (strip till zone where corn is planted with no cover crop) and in between corn rows (under the perennial cover crop). The field moist monthly samples will be analyzed for ammonium and nitrate concentrations to assess soil N-dynamics, and the growing crop will be analyzed bi-weekly with a SPAD meter to assess plant N status. The monthly samples will also be analyzed for labile C- and N by incubation to measure respiration and PMN. The impact of the perennial cover crops and strip tillage management system on soil C and N dynamics will be reported.