Evaluation and comparison of the sustainability of autumn and spring sugar beet production systems using emergy...

This study investigates and compares the sustainability of autumn and spring sugar beet production systems in Khorasan Razavi Province using emergy indicators. The primary objective of this research is to determine the environmental pressure exerted on the agricultural ecosystem by each system and to compare their reliance on renewable and non-renewable resources. Data on inputs and outputs of the autumn and spring sugar beet production systems were collected through two methods: face-to-face interviews and field surveys, as well as direct observations by the researchers. The total emergy input for the autumn and spring sugar beet systems was calculated as 2.93E + 16 and 3.28E + 16 sej (solar emjoules), respectively. Analysis of emergy indicators revealed that the majority of emergy inputs in both systems rely heavily on non-renewable resources, particularly groundwater, with groundwater accounting for 27.98% of the total emergy input in autumn systems and 34.40% in spring systems. The environmental sustainability index for both production systems was less than one, indicating weak sustainability. The standard and modified environmental loading ratios for the autumn sugar beet system were 110.88 and 20.11, respectively, while for the spring system, they were 209.82 and 26.46. The results of this study demonstrate that spring production systems impose greater environmental pressure on the agricultural ecosystem compared to autumn systems and exhibit lower sustainability. Although spring systems yield higher production per unit area, this comes at the cost of increased consumption of non-renewable resources. These findings underscore the necessity for optimal resource management and enhanced productivity in spring systems to mitigate environmental impacts. The results provide evidence-based guidance for policymakers and farmers in semi-arid regions.