Extended exergy accounting of agricultural resources in China's four provinces of mountains and rivers.

The agricultural sector in China has to balance resource investment, environmental emissions and yields to satisfy the high dietary demands of the population. In this study, extended exergy accounting (EEA) was conducted to analyse the usefulness of resources invested in agriculture and the yields of strategic importance to China in Hebei, Shanxi, Shandong and Henan (four provinces of mountains and rivers) in 2017 from a thermodynamics perspective. The fluxes resources of energy, materials, environmental emissions, labour, capital and yields were measured in joules. The results revealed that the exergy from the natural environment, with an energy exergy value of 9.92 EJ, contributed the most to the agricultural sector in the region. The labour and capital exergy values were much lower than those of the other resources. The non-renewable resource inputs were exceeded by emissions. Animal wastes accounted for 80% of emissions. The resource conversion efficiency in Shandong was 0.46, which was higher than those in the region and China. Shanxi exhibited considerable potential to increase its resource conversion efficiency. EEA was applied in agroecological systems to diagnose the shortage of resource depletion and environmental emissions which could be adopted in other zones or sectors from sustainable development perspective.