Investigation of CO2 emission from soil and farm inputs in different farming systems in wheat-maize rotation

Abstract

In this study, the amounts of greenhouse gas (equivalent to CO2) emitted from inputs consumption and CO2 emission from the soil in the various wheat-maize farming systems for one year were evaluated in an experimental design. In the studied systems, the CO2 eq emission from the inputs for wheat and maize ranged from 258 to 365 kg.ton− 1 and 140 to 313 kg.ton− 1 respectively, which electricity, fertilizer and fuel inputs had the largest share. By changing the agricultural systems, there was a potential to reduce CO2 eq emission from the inputs by up to 29% per ton of wheat and up to 55% per ton of maize. Results showed that residue management, irrigation method, and tillage had significant effects on CO2 emission from the soil, while planting method showed no significant effect. Systems with residue (R1) had about 28% higher CO2 emission from the soil, by changing the tillage method from conventional tillage (T1) to no-tillage (T3) and changing the irrigation method from flood (I1) to drip (I2), a reduction of approximately 20 and 12% in emission was observed, respectively. Among the studied systems, the highest amount of CO2 emission from the soil was observed in the system with residue, conventional tillage, flood irrigation, and flat planting (R1T1I1P1) with a rate of 7.35 kg.ha− 1 per day. The highest total CO2 emission from inputs and emission from the soil were observed in R1T1I1P1 system with a rate of 6129.47 kg.ha− 1 per year, which decreased to 4471.28 kg.ha− 1 per year in R2T3I2P2 system.