Harvesting rice straw management synergies for lifecycle environmental and economic sustainability.

Rice is a critical global staple food; however, its production is a substantial contributor to greenhouse gas emissions. The burning of rice straw (RS), a byproduct of the harvest, further exacerbates global warming by emitting greenhouse gases and air pollutants, such as particulate matter, contributing to biodiversity loss and soil fertility degradation in agricultural areas. To explore the synergies of RS bioresources, this study systematically evaluates various RS management practices, including open burning, soil organic amendment, and bioenergy production, from the perspective of their lifecycle environmental and economic performance. This study considers all stages of rice production, including different irrigation systems such as conventional flooding and alternate wetting and drying (AWD). The findings indicate that replacing conventional flooding with AWD irrigation results in reduced lifecycle environmental impacts across all midpoint indicators. Specifically, AWD irrigation combined with RS used as soil amendments exhibits the lowest global warming potential, at -435.2 kg COeq per ton-RS. In terms of economic costs, the lifecycle costs across all scenarios range from approximately 91.7 to 186.9 USD per tonne of RS. Furthermore, sensitivity analyses are conducted on RS portion allocation and transportation distance. The study also identifies the synergies between soil organic amendment and bioenergy production, leveraging global carbon pricing and feed-in tariffs, as crucial factors for optimizing both the environmental and economic performance of RS management. This study offers valuable insights into the potential of integrated RS management practices for achieving environmental sustainability and economic viability over the rice production lifecycle.