Analysis of energy input-output in direct seeded and transplantation cultivation of rice under different irrigation systems

Abstract

Energy input-output assessment for crop production processes is becoming increasingly important due to increased energy demand. This study explored the energy consumption for puddled transplanted (PTR), un-puddled transplanted (UPTR), and direct-seeded rice (DSR) cultivation methods under sprinkler, flood and drip irrigation systems in Golestan province, Iran, during 2019 and 2020. The energy of inputs and outputs were calculated using energy equivalents. Then, using input energy values, the global warming potential (GWP) was determined based on the equivalent of carbon dioxide (CO2). According to the results, the highest amount of yield was obtained for permanent flood irrigation with PTR. The results of mean comparison of cultivation method showed that the highest and lowest amounts of energy input were obtained for PTR (32418 MJ/ha) and UPTR (28175 MJ/ha), respectively. Also, the amounts of indices of energy use efficiency (EUE), energy productivity (EP) and net energy (NE) in DSR were lower than transplanted treatments. The results of mean comparison showed that the lowest amount of GWP was related to UPTR. The results of this study showed that drip irrigation with UPTR cultivation (due to less energy input and a yield close to PTR) can be a technology to save water and energy.