energy flow and global warming potential GWP of Corn farm (Gorgan city).

The aim of this study was investigation the energy flow and global warming potential (GWP) of corn farm in Gorgan city. For this purpose, data were collected from three conventional planting methods (spring planting, summer planting in wheat residue and summer planting without wheat residue) by using a face-to-face questionnaire performed with farmers in summer 2012. After the required data in three parts, fuel consumption, energy consumption and global warming potential on the basis of the CO2. The results revealed that total energy consumption amount in spring panting, summer planting in wheat residue and summer planting without wheat residue was 26355.7, 28395.4 and 27783.2 MJha-1, respectively. The highest share of total input energy was recorded for nitrogen fertilizer and diesel fuel in all planting methods.The least GWP was obtained from spring planting with 2349kg Equivalent to Co2. So spring planting had less environmental effects. According to the results use of high yielding hybrids, residue management and nitrogen fertilizer is essential for increase energy efficiency and reducing Environmental effects.