本文研究了土壤碱解氮快速测定的可行性及不同还原剂对碱解氮测定值的影响。结果表明，提高碱液浓度和碱解扩散温度，均可缩短碱解扩散时间。当氢氧化钠浓度为；１．８ｍｏｌ／Ｌ，扩散温度为４０℃与７０℃时，所需扩散时间分别为２４ｈ与４．８ｈ．当氢氧化钠浓度为４ｍｏｌ／Ｌ时，６０℃需扩散５．２ｈ，７０℃只需要３．２ｈ。当用０．２ｇ德氏合金作还原剂时，ｌｍｏ１／ＬＮａＯＨ碱解扩散温度为３０℃、４０℃与５０℃时的扩散时间分别为７．７、４．６与３．３ｈ。 This paper studied the feasibility of rapid determination of soil available nitrogen and the effect of different reducing agents on the determination of available nitrogen. The results show that increasing alkali concentration and alkali diffusion temperature can shorten the alkali diffusion time. When the sodium hydroxide concentration is 1.8mol / L, the diffusion temperature is 40 ℃ and 70 ℃, the required diffusion time is 24h and 4.8h respectively. When the sodium hydroxide concentration is 4mol / L, it needs to diffuse for 5.2h at 60 ℃ and only 3.2h at 70 ℃. When 0.2g Des alloy was used as reductant, lmo1 / LNaOH alkali diffusion temperature was 30 ℃, diffusion time at 40 ℃ and 50 ℃ were 7.7, 4.6 and 3.3h respectively.