A comparative study on energy use of rice (Oryza Sativa L.) cultivars under mechanized cropping systems in West of Turkey

The study was performed energy analysis of mechanized rice production for two rice cultivars under a region, named Çanakkale, in West Turkey. The indicators are energy use efficiency, specific energy, energy productivity and net energy. The cultivars of rice commonly grown in the region are listed in two groups: native and high yield hybrid. Primary data were obtained through field survey with farmer's interviews face to face with a questionnaire in Biga, Ezine and centre districts, commonly rice cultivation areas in the region. Secondary data and energy equivalents were obtained from available literature using collected data of the production period of 2020-2021. Analysis of data showed that averagely diesel had the highest share within the total energy inputs as 46.46% and 45.72% for native and hybrid, respectively, followed by chemical fertilizers with 24.19%, and 23.80%, especially nitrogen. Water input was the third highest share with 11.29% and 11.60% for native and hybrid, respectively. Machinery input had fourth share in total, but it showed similar percentage with around 8.00% in both cultivars because of receiving similar machinery operations. Another high input was pesticides with around 4.00% because herbicides using is very high, especially for annual and perennial sedges and broadleaf weeds. Labour is the optimum level because of cultivation practices are usually performed by mechanical power. Net energy was found higher in hybrid cultivar with 101.41MJ ha-1 due to higher grain and straw yield than native with 84.01 MJ ha-1 . The energy use efficiency and energy productivity of nature cultivar were 2.3 and 0.12 kg∙MJ-1 , respectively, corresponding to increases of 2.5 and 0.13 kg∙MJ-1 in hybrid. With appropriate agronomic measures in rice production in the study area, higher yield of hybrid cultivar would necessarily lead to an increase in energy productivity and gain.