Assessing the bioenergy potential of abandoned cropland in China: Toward an optimal distribution of bioenergy crops

Bioenergy has gained wide attention due to its potential to reduce fossil fuel consumption and greenhouse gas emissions. Abandoned cropland is a promising option for cultivating bioenergy crops, as it does not compete with food production. The vast amount of abandoned cropland in China provides extensive opportunities for the development of bioenergy. However, the bioenergy potential of China's abandoned cropland remains unclear. In this study, we identified abandoned cropland in China for the period of 2000–2020. Based on this, we estimated the bioenergy potential from conventional food crops (maize and wheat), and perennial bioenergy crops (miscanthus and switchgrass), on the abandoned cropland in China. We optimized the planting of conventional food and two perennial bioenergy crops by maximizing crop yield and accounting for water limits. The results show that 29.49 Mha of abandoned cropland was found in the past twenty years. Spatially, it was mainly located in eastern China with relatively high soil quality, in contrast to that in the U.S. and Europe. By optimizing the crop distribution on abandoned cropland, the bioenergy potential primarily shows a spatial distribution of higher potential in the south and lower potential in the north, with a total yield reaching 9.52 EJ. This is approximately 1.43 times higher than that of solely cultivating miscanthus and 8.28 times that of wheat. This potential accounts for 6 % of China's total primary energy consumption in 2022 and 7.66 % of the carbon emission peak target for 2030. It holds significant importance for the national emission reduction strategy. These findings highlight the immense bioenergy potential of abandoned cropland, providing support for the development of bioenergy.