煤粉尘添加量与温度对山西省两种土壤碳释放规律的影响

Effects of coal dust and temperature on CO_2 emission in two soil types in Shanxi Province

采用室内培养试验,观测不同温度和不同煤粉尘用量条件下山西省电厂土和焦化厂土两种土壤的碳释放规律。结果表明,室温(16～23℃)和25℃恒温下,培养前期(4～9 d)土壤CO2的释放量均为最大,且25℃恒温培养土壤CO2的释放量是室温条件下的2倍左右。随煤粉尘添加量的增加,土壤CO2的释放量显著增加,且土壤活性有机质相应增加,添加高量煤粉尘土壤CO2的释放量最高达57.5 mg.kg-1.d-1,两种土壤活性有机碳的增幅为0.3～3.8 g.kg-1。不同温度和不同煤粉尘用量条件下电厂土释放的CO2均高于焦化厂土,可能是电厂土含有较高的有机碳和较低的黏粒所致。由此可知,温度是影响土壤有机碳分解的主要因素,其次是添加煤粉尘的量,土壤理化性质也是原因之一。本研究表明,煤粉尘的降落一方面增加了土壤CO2的释放,另一方面增加了土壤碳库。

By using incubation experiment,the effects of temperature and coal dust application degrees on soil organic carbon decomposition were measured in two soil types（soils from power generation and coke oven plants） in Shanxi Province.The results show that CO2 emission rates were higher in the early days under both room temperature（16～23 ℃） and 25 ℃ than those in the rest of the incubation period.In fact,CO2 emission rate at 25 ℃ was twice that at room temperature.Furthermore,CO2 emission rate and soil labile organic matter increased with increasing application degree of coal dust.At the highest possible application degree of coal dust,CO2 emission rate rose to 57.5 mg·kg？1·d？1,and labile organic matter content of two soil types increased by 0.3～3.8 g·kg？1.Under different temperature and application degrees of coal dust,the amount of CO2 emitted by the power generation plant soil was higher than that emitted by the coke oven plant soil.This may because of much more organic carbon and less clay particular in power generation plant soil.It also suggested that soil organic carbon decomposition was mainly driven by temperature.However,coal dust and soil physical and chemical properties also influenced the soil organic carbon decomposition.More importantly,coal dust increased soil CO2 emission while it at the same time improved soil carbon pool.