2024 年 34 巻 S 号 p. 59-63
Soil degradation due to salinity and sodicity is one of the most important impediments to agricultural production in China. In addition, the need for the development of new, clean coal-refining technologies has risen in China. As a background of this research, salt-affected soils were ameliorated with coal bio-briquette ash, and the positive effects and the increase in carbon due to the soil amelioration have been confirmed. Moreover, the effect of salts leaching into coal bio-briquette ash has been investigated by using a soil column equipped with tensiometers and four-electrode sensors. Combustion ashes from coal bio-briquettes made from low-quality coal, biomass (corn stem), and a desulfurization agent (Ca(OH)2) were examined to two types of salt-affected soil of higher EC and exchangeable sodium percentage (ESP) by the column equipment. Consequently, initial Na leaching was confirmed from the results of the leachate EC and Na content of the leachate at 3.0 wt% and 6.0 wt% application rates. Amelioration in the soil of higher EC and ESP with the coal bio-briquette ash was effective at a higher application rate. These results also indicate that ash has the possibility of ameliorating high-EC and high-ESP soils. Finally, we could predict the necessary water volume for Na leaching by using the experimental results and the meteorological data and could estimate the quantity of irrigation water necessary. These results indicated the effectiveness of using low-quality coal bio-briquette ash as a soil amendment to salt-affected soil of higher EC and ESP.
