Soil Greenhouse Gas Emissions from Three Decades Long-term Experimental Field of Corn-Soybean Rotation and Tillage Treatments

Reduction of greenhouse gas (GHG) emissions from upland crop field as well as paddy field is being required, but little information on GHG emissions according to culti- vation practices in upland field is available. Soil GHG emissions during the growing season were investigated in the field of three decades rotation and tillage treatments which were consisted of plow, chiesl tillage and no tillage in west central Indiana, USA in 2006. Seasonal cumulative CO2 emissions were not different among treatments. CH4 emission increased a little in plow tillage during early soybean growing season. Most of N2O emission occurred during early corn growing season after N-fertilizer application from mid June to mid July, and was significantly affected by tillage practices in which seasonal cumulative N2O emission was significantly higher under chisel tillage. N2O emission under no-tillage was lower about 64% and 39% than that under chisel tillage and plow tillage, respectively. No-tillage practice with rotation of corn and soybean seems to be promising in point of less GHG emission and less labor for cultivation without grain yield reduction.