丘陵山区覆膜旱作稻田土壤硝态氮和铵态氮动态变化规律探讨

Dynamics of Ammonium and Nitrate Nitrogen in Rainfed Rice Soil under Plastic Film Mulching Cultivation in Mountainous Region

采用田间长期定位试验对丘陵山区连续4年覆膜旱作、裸地旱作和常规水作条件下稻田土壤硝态氮和铵态氮的动态变化规律作了研究。结果表明,覆膜旱作稻田土壤的铵态氮和硝态氮显著高于常规水作,土壤NO3--N占无机氮的81.16%～90.46%,是土壤铵态氮的4.32～9.49倍。因此,丘陵山区覆膜旱作稻田土壤矿质氮主要以硝态氮为主。

The experiment was conducted to study the dynamics of soil NO^- 3-N and NH^＋ 4 -N in mountainous region under 4 years rice plastic film mulching cultivation. The treatments included plastic film mulching with non-flooding, no plastic film mulching with non-flooding and traditional flooding. The results showed that plastic film mulching significantly increased the content of soil NO^- 3-N and NH^＋ 4-N compared with traditional flooding during rice growth stages. The content of NO^- 3-N was 81.16%-90.46% of mineral N and 4.32 to 9.49 times as much as NH^＋ 4-N. We suggested that NO^- 3-N was dominant in rainfed rice soil mineral N under plastic film mulching condition.