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[目的]探讨传统施肥和测土配方施肥对暗棕壤中氮的形态及其在不同大小团聚体中分布的影响。[方法]采用物理与化学相结合的方法对传统施肥模式和测土配方施肥模式下暗棕壤不同粒径团聚体中氮的分布和化学形态进行比较研究。[结果]与传统施肥春秋两季相比,在测土配方施肥模式下,0~20cm层土壤全氮平均减少了23.2%和20%,而20~40 cm层土壤全氮平均减少了48.8%。铵态氮对施肥模式变化极为敏感,在测土配方施肥模式下,秋季的铵态氮下降幅度明显高于传统施肥模式。传统施肥模式土壤氮素主要分布在0~0.25和0.5~1 mm的团聚体中;而测土配方施肥模式土壤氮素主要分布在0.25~0.5和0~0.25 mm团聚体中。研究证实测土配方施肥模式减少了氮素面源污染的风险;测土配方施肥极大地影响暗棕壤中氮素的形态及其在不同大小团聚体中的分布。[结论]该研究为辽河源头区面源污染和该地区的科学施肥提供科学依据。
[Objective] The purpose was to discuss the effect of traditional fertilization and soil testing and fertilization on nitrogen form and its distribution in different sized aggregates in dark brown soil. [Method] The physical and chemical methods were used to compare the distribution and chemical forms of nitrogen in aggregates with different particle sizes of dark brown soil under the traditional fertilization mode and the soil testing and fertilization mode. [Result] Compared with the traditional spring and autumn seasons, soil total nitrogen in 0 ~ 20cm layer decreased by 23.2% and 20% on average while soil total nitrogen in 20 ~ 40 cm layer decreased by 48.8% . Ammonium nitrogen is very sensitive to the change of fertilization mode. In the soil testing and fertilization mode, the declining rate of ammonium nitrogen in autumn is obviously higher than that of the traditional fertilization mode. In the traditional fertilization mode, soil nitrogen was mainly distributed in the 0 ~ 0.25 and 0.5 ~ 1 mm aggregates. Soil nitrogen in the soil testing and fertilization modes was mainly distributed in the aggregates of 0.25-0.5 and 0-0.25 mm. The results showed that the soil testing and fertilization mode reduced the risk of nitrogen non-point source pollution. Soil testing and fertilization greatly influenced the nitrogen form and its distribution in different sized aggregates. [Conclusion] The study provided a scientific basis for non-point source pollution in the source area of Liaohe River and scientific fertilization in this area.