Soil freeze–thaw can alter the soil nitrogen (N) mineralization rate by increasing root litter. However, the mechanism remains unclear. We compared the effect of adding root litter from two plant species on soil production rate and soil production rate under low‐temperature conditions in laboratory incubation. Root litter of oak (Quercus crispula) or dwarf bamboo, Sasa (Sasa nipponica) was added to soil and incubated under nonfrost and soil freeze–thaw treatments. We monitored temporal change of net/gross production rate and production rate throughout the soil frost period and the following melting period. We measured dissolved organic N (DON) in root litter leachate under the two temperature treatments. The soil N mineralization with Sasa root litter was higher than that with oak root litter in the two temperature treatments. The DON in root litter leachate of Sasa was larger than that of oak. The effect of root litter addition on net production rate was larger than that on net production rate. The higher net production rate of soil with Sasa was considered to be caused by higher DON in leachate from root litter of Sasa. The higher inducement of N mineralization of Sasa root litter than oak root litter was related to quantity of organic N in the root litter leachate.

中文翻译：

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日本北部阔叶林土壤中添加凋落物对实验室低温条件下土壤氮矿化率的影响

土壤冻融可通过增加根凋落物来改变土壤氮（N）的矿化速率。但是，机制尚不清楚。我们比较了在实验室培养条件下在低温条件下从两种植物中添加根凋落物对土壤生产率和土壤生产率的影响。将橡木（Quercus crispula）或矮竹Sasa（Sasa nipponica）的根垃圾添加到土壤中，并在非霜冻和土壤冻融处理下孵育。我们监测了净/总生产率的时间变化和整个土壤霜冻期和随后的融化期的生产率。我们在两种温度处理下测量了根凋落物渗滤液中的溶解有机氮（DON）。在两个温度处理下，Sasa根凋落物的土壤氮矿化程度高于橡木根凋落物。Sasa根垃圾渗滤液中的DON比橡木大。根凋落物添加对净生产率的影响大于对净生产率的影响。Sasa土壤较高的净生产率被认为是由Sasa根凋落物渗滤液中的DON较高引起的。Sasa根凋落物中氮矿化的诱导程度高于橡树根凋落物，这与根凋落物中的有机N含量有关。