Increase energy use efficiency and economic benefit with reduced environmental footprint in rice production of central China

Abstract

Identifying an energy-efficient system with low energy use, low global warming potential (GWP), and high profitability is essential for ensuring the sustainability of the agro-environment. Given the global importance of China's rice production, this study determines energy, environmental, and economic performances of transplanted (TPR) and direct-seeded rice system (DSR) in central China. The results showed that total energy inputs for TPR and DSR were 31.5 and 22.8 GJ ha -1 across two growing seasons, respectively. Higher energy input for TPR primarily resulted from extra energy use of the nursery beds and transplanting. Higher energy output of DSR (202.5 GJ ha -1 ) over that of TPR (187.7 GJ ha -1 ) was due to a slightly higher yield from DSR. Therefore, DSR exhibited significantly higher energy use efficiency than that of TPR. Lower specific energy for DSR (2.78 MJ kg -1 ) relative to TPR (4.02 MJ kg -1 ) indicated that the energy used to produce per unit of rice grain could be reduced by 30.8% by adopting DSR. On average, GWP of DSR was reduced by 5.6% compared with TPR. Moreover, DSR had a 55.8% higher gross return and a 25.7% lower production cost than those of TPR. Overall, compared with TPR, DSR has the potential to increase gross economic return and energy output with reduced energy input and emissions. Therefore, this study suggests that DSR is an environmentally-sound and economically-viable production system. As such, DSR is noted as an energy-efficient and climate-smart production system that could be used by policymakers and farmers to achieve not only improvements in the environment but also financial benefits.

Ratoon Rice Cropping Mitigates the Greenhouse Effect by Reducing CH4 Emissions through Reduction of Biomass during the Ratoon Season

“…Therefore, the NEEB of the main season was significantly higher than that of the early season (Table 5), which is in agreement with the report of Xu et al [25]. Compared with the ratoon season, the late season rice production requires seeds and labor for seeding, tilling, and transplanting [22]. In addition, the lower GWP in the ratoon season led to lower total cost relative to the late season (Tables 3 and 5).…”

“…In addition, agricultural management has great impacts on paddy GHG emissions, and fertilizer (particularly nitrogen fertilizer) application and tillage can increase CH 4 and N 2 O emissions from paddy fields [18][19][20]. Therefore, the selection of appropriate rice varieties and agricultural management in rice cropping systems may enhance the grain yield and lower agricultural GHG emissions [21][22][23].…”