Comparative life cycle cost-energy and cumulative exergy demand of paddy production under different cultivation scenarios: A case study

Abstract

The use of energy efficient in agriculture is one of the important factors to achieve sustainable production in agriculture. Considering the limited resources and the importance of preventing the loss of resources, it is necessary to evaluate investment projects from an economic point of view This study applying life cycle assessment (LCA) of paddy production in Khuzestan province of Iran were studied, LCA is a methodology for assessing environmental impacts associated with all the stages of the life cycle of a commercial product, process, or service. In this study, energy indicators, economic analysis and LCA of paddy production in Khuzestan province of Iran were studied. Paddy production in this province was analyzed under three scenarios of multiple cultivation system including (Paddy-Transplantation System) PTS, (Paddy-Flooding System) PFS and (Paddy- Drying System) PDS. The highest total input (79069.80 MJ ha−1) and output (105400 MJ ha−1) energies are related to PTS method. PDS method has the lowest energy production and consumption. Diesel fuel and nitrogen fertilizers consume a lot of energy. Electricity and water showed 13 % of energy consumption in PFS method. Depending on the type of cultivation in PDS method, human labor has a large share of energy. The results of benefit to cost ratio showed of PTS method (6.60) shows the high profit of rice production from the amount of cost. Categories of damage to human health, ecosystems and resources were reported according to ReCiPe2016 method for paddy production. The resource impact category for PDS (114.76), PFS (111) and PTS (102.60) USD2013 is the highest to the lowest, respectively. The categories of human health damage for PTS, PFS and PDS methods were 0.041, 0.04 and 0.05 DALY, respectively. The resource category accounts for a significant portion of environmental emissions. Results of CExD showed the non-renewable, fossil form has a significant value in PTS (12980.06), PFS (14215.41) and PDS (14544.40) MJ ton–1, also that nitrogen fertilizer and the use of machinery and diesel fuel have the greatest impact on energy forms.