Mitigating greenhouse gas emissions, increasing grain yield and farmer income in rice cultivation through the utilization of rice husk ash as soil amendment

Utilization of rice husk ash (RHA) as soil amendment is in rice production therefore would provide one of the alternative ways for sustainable rice production and in line with bio green circular economy concept. In this study, we hypothesized that with its nutrient value such as high silica content it would promote rice growth and yield, and reduce greenhouse gas emission. Effects of RHA were investigated in a greenhouse experiment in 2020. Acid sulfate clay soil samples were collected from paddy fields in Prachinburi provinces. Four different treatments with three replications in a completely randomized design were prepared. RHA was homogeneously incorporated into the soil at rates of 1.55, 4.66, and 9.33 g kg 1soil. It was found that soil pH was increased by 0.39 0.59 unit under RHA amendment. The combined GWP of CH4 and N2O under RHA application was significantly decreased by 7 31% compared with the control. Rice yield was significantly increased under RHA amendment by 22 31% compared with the control. Accordingly, the yield
scaled GWP was significantly decreased by 24 44% compared with the control. Although the cost of rice cultivation was increased partly by RHA purchasing and transportation, the net income from the increase in grain yield increases was significantly higher in RHA addition compared with the control, by 109–355 USD ha−1 crop−1.