Shiva Ladan, Indiana U./Purdue U Indianapolis, Indianapolis, IN and Pierre-Andre Jacinthe, Department of Earth Sciences, Indiana University Purdue University Indianapolis, Indianapolis, IN
Nitrous oxide (N2O) is an atmospheric constituent that has been implicated in climate warming and stratospheric ozone depletion. Among anthropogenic activities, agriculture is the largest N2O producer contributing about 62% of total N2O emission. Therefore, agricultural land management decisions could influence atmospheric N2O burden. During the last several decades, no-till (NT) farming has been widely adopted as a better tillage practice compared to conventional plowing (PT). However, the net effect of NT on N2O emission and the factors involved are not well understood. In this study, we investigated the N2O production potential of soils under long-term NT (10 to 48 years) relative to PT and forest soils. A selective inhibition technique using different biocides has been used to determine the relative contribution of fungi and bacteria to the denitrification process in various types of soils. Additional experiments are underway to optimize the selective inhibition assays. Results will help clarify some of the controversies surrounding NT farming.