Energy and CO2 emission assessment of wheat (Triticum Aestivum l.) production scenarios in central areas of Mazandaran province, Iran

Abstract

Climate change is a global concern and part of it is due to agricultural activities. Therefore, optimizing the agricultural operation is seen as a strategy to alleviate climate change effects. The purpose of this research was energy and carbon dioxide emission assessment in wheat production. To do so, first, six conventional wheat planting fields were identified in the counties of Jouybar, Ghaemshahr and Sari in Iran, in 2015. Then, through improved planting methods (based on growing low-input wheat, designed by researchers) they were compared. The identification of the field was done in a way that covered all main production methods in each county. After that, the improved and conventional methods of planting in the three counties were investigated as four scenarios. The results showed that the average input energy in four scenarios was 11811.61 MJ ha-1 where the least input energy in the improved scenario was 11169.72 MJ ha-1. The highest portion of input energy in the four scenarios was of nitrogen fertilizer with average of 4492.14 MJ ha-1 and 38.03 per cent of it had the highest rate of CO2 emission and global warming potential (GWP). Fuel, phosphorus fertilizer, and seed held the next rank of CO2 emission. The average GWP of wheat production in the four scenarios was 894.07 kg CO2 per ha-1. The lowest and highest amount of GWP were 710.2 and 933.59 kg CO2 per ha-1 in scenarios I and II, respectively. Moreover, the amount of GWP per energy input unit was the maximum in scenario II and minimum in scenario IV. Furthermore, the improved scenario had the lowest GWP per energy output unit and scenario I achieved the first rank. In general, the amount of GWP has a direct relationship with the method of field management and input consumption.