Investigation on energy use efficiency and greenhouse gas emissions (GHG) of onion cultivation

In this study, the energy of inputs and output used by the farms cultivating onion in Adiyaman province in Turkey were determined. The inputs were classified into direct, indirect, renewable and non-renewable energy types. Energy output-input ratio, specific energy, energy productivity and net energy calculations were done for calculating energy use efficiency. In the study, questionnaire, observation, and calculation methods were used. Survey, observation and study data calculations include the 2018 production season. The data supplied from study were collected from 20 different farms (can be reached) by face to face survey with full count method. Energy inputs in onion cultivation were calculated as 22463.52 MJ ha-1, energy output was calculated as 49704 MJ ha-1. 60.43% of the energy inputs included of chemical fertilizers (nitrogen, phosphorous and potassium) energy (13574.55 MJ ha-1), 15.34% included of human labour energy (3445.07 MJ ha-1), 12.05% included of diesel fuel energy (2706.82 MJ ha1), 6.44%o included of machinery energy (1446.98 MJ ha-1), 3.02% included of irrigation water energy (679.30 MJ ha-1), 1.71% included of chemicals energy (384.56 MJ ha-1) and 1.01% included of seed energy (226.23 MJ ha-1) in onion cultivation. Energy use efficiency, specific energy, energy productivity and net energy in onion cultivation were calculated as 2.21, 0.72 MJ kg-1, 1.38 kg MJ"1 and 27240.48 MJ ha-1, respectively. The consumed total energy input in onion production can be classified as 30.41%) direct, 60.59%) indirect, 19.37%o renewable and 80.63%) non-renewable. Total GHG emissions were calculated as 2920.73 kgCO2-eqha-1 for onion cultivation with the greatest input part for human labour usage (42.13%). The human labour usage followed up chemical fertilizers (nitrogen, phosphorous and potassium) usage (37.71%o), irrigation water usage (6.28%), diesel fuel usage (4.54%), seed usage (4.02%), machinery usage (3.52%) and chemicals usage (1.81%), respectively. Additionally, GHG ratio value was calculated as 0.094 kgCO2-eqkg-1 in onion cultivation.