采煤塌陷地积水对土壤氮素矿化过程的影响

Effects of waterlogging on the soil nitrogen mineralization in coal mining subsidence land

煤炭开采导致大面积的土地塌陷,使大量耕地出现常年积水或季节性积水,对塌陷地土壤氮素矿化过程产生一定影响。采集了某矿采煤塌陷地土壤样品,进行好气和淹水培养条件下间歇淋洗培养实验,研究了塌陷地积水对土壤氮素矿化过程的影响。经过62d的培养,40d左右氮素的矿化过程趋于稳定,淹水培养条件下土壤氮素最终累积矿化量为68.99mg/kg,约为好气培养条件的10倍,且淹水培养条件下土壤氮素矿化势可达69.472mg/kg,均矿化速率为5.210mg/(kg·d),说明淹水对土壤氮素矿化过程有显著的促进作用。将实验所得累积矿化量分别代入简单指数模型及双因子指数模型进行拟合,发现简单指数模型能有效模拟好气和淹水培养条件下土壤氮素矿化过程,并获得了2种培养条件下土壤氮素矿化过程的模型参数。

Mining area subsidence resulting from underground coal mine mining has lead serious seasonal or pe- rennial waterlogging of farm land. Especially in the high watertable area,water emerging directly affects nitrogen min- eralization in the soil. The soil samples in coal mining subsidence land were collected for simulating the nitrogen miner- alization process at both aerobic and waterlogged conditions, the effect of waterlogging on nitrogen mineralization is in- vestigated during 62 days of experiment. The results show that the nitrogen mineralization is tending to stabilize at the 40th day;the mineralized nitrogen in waterlogging condition during 62 days incubation process is 68.99 mg/kg,which is ten times as much as that in aerobic condition. Moreover, the nitrogen mineralization potential and velocity constant are 69. 472 mg/kg and 5. 210 mg/（kg ~ d） respectively according to the calculation. Therefore, waterlogging condition promotes soil nitrogen mineralization. Both simple exponential and double exponential were used to fit the experiment results mathematically. And simple exponential model fits better for the data of N mineralization under both aerobic and waterlogged conditions.