土壤中铵的固定与温度的关系及调控
Ammonium fixation as affected by soil temperature and its management
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摘要: 采用实验室培养方法 ,研究了褐土与潮土中肥料氮的矿物固定与土壤温度的关系及利用盆栽15N同位素示踪方法 ,研究了小麦施肥时的环境温度对铵的固定及肥料氮有效性的影响。结果表明 ,25℃常温条件下 60d内肥料氮的固定率为 18%~ 22.92% ,但在-5~0℃的低温下则达 37.69%~45.31% ,低温较常温条件下肥料氮的固定率增加一倍左右。在盆栽条件下 ,利用低温季节施肥可增加肥料氮的暂时固定 ,而固定后的肥料氮在小麦生长季节内基本全部释放 ;低温季节施肥可提高肥料利用率 ,增加了肥料氮在土壤中的残留 ,减少了肥料氮的损失Abstract: The fixation of the fertilizer-NH4+ affected by soil temperature and its management through nitrogen application under different seasonal temperature were studied in two main soils of Hebei, using incubation and 15N tracing methods. Results showed that the fixation rate of the fertilizer-NH4+ was 18%~22.92% at normal temperature (25℃) and 37.69%~45.31% at low temperature (-5~0℃) under incubation condition. The fertilizer-N fixation increased temporarily when it was applied in low temperature season under pot culture condition. But the fixed fertilizer-N was released almost entirely during the growing season of the wheat. Fertilization,under low temperature, the higher nitrogen efficiency was obtained. The residual rate of the fertilizer-N increased and its loss decreased.