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更好地了解温度和湿度对土壤氮矿化过程的影响 ,从而估计森林生态系统土壤有机氮的矿化速率。在实验室条件下 ,控制土壤的温度与含水量。将不同含水量 (0 .12、0 .2 0、0 .2 8、0 .35、0 .40 kg· kg- 1 )的土柱置于 5℃、15℃、 2 5℃和 35℃条件下培养 30 d。分析培养前后的 NH+ 4 - N和 NO- 3 - N含量 ,确定土壤的净矿化速率和净硝化速率。结果表明 :在 5～ 2 5℃的温度范围内 ,氮的矿化速率和硝化速率与温度和湿度呈正相关。当温度超过 2 5℃ ,含水量超过 0 .2 0 kg· kg- 1 时 ,净矿化速率和净硝化速率随着温度和含水量的升高反而降低。温度和湿度对土壤的矿化和硝化过程存在比较明显的交互作用。我们建立了二维的方程 (T,θ)来描述温度和湿度对土壤氮矿化速率的影响。暖温带土壤氮矿化的最佳条件是温度 2 2 .4℃、含水量 0 .40 kg· kg- 1 。另外试验过程中 ,还观察到了比较明显的土壤氨挥发现象
To better understand the effects of temperature and humidity on soil nitrogen mineralization, and to estimate the rate of soil organic nitrogen mineralization in forest ecosystems. Under laboratory conditions, control soil temperature and water content. Soil columns with different water contents (0 .12,0 .2 0,0 .2 8,0 .35,0 .40 kg · kg-1) were placed under the conditions of 5 ℃, 15 ℃, 25 ℃ and 35 ℃ Under training 30 d. The contents of NH + 4 - N and NO - 3 - N before and after culture were analyzed to determine the net mineralization rate and net nitrification rate. The results show that the mineralization rate and nitrification rate of nitrogen are positively correlated with temperature and humidity in the temperature range of 5 ~ 25 ℃. When the temperature exceeds 25 ℃ and the water content exceeds 0 220 kg · kg -1, the net mineralization rate and the net nitrification rate decrease with the increase of temperature and water content. Temperature and humidity on soil mineralization and nitrification process there is a more obvious interaction. We established a two-dimensional equation (T, θ) to describe the effects of temperature and humidity on soil N mineralization rates. The optimum conditions for nitrogen mineralization in warm temperate soil are temperature of 22.4 ℃ and water content of 0.40 kg · kg-1. In addition, during the experiment, the obvious phenomenon of soil ammonia volatilization was also observed