氮是植物生长所必需的,土壤中的氮素供应状况与植物生长的关系极为密切。土壤中的有效态氮以铵或硝酸盐的形态存在。为了测定土壤中的铵,过去一般用蒸馏滴定法或比色法,但前者手续冗长,后者误差较大。近年来随着气敏电极的发展,已经广泛地应用氨气电极测定水或土壤及植物中的含氮量。我们试制成了氨气电极,根据初步应用的情况看,使用这种电极,可以达到在田间快速测定土壤中铵的目的。一、电极制造和测定方法 Nitrogen is required for plant growth and the relationship between nitrogen supply in the soil and plant growth is very close. The available nitrogen in the soil is in the form of ammonium or nitrate. In order to determine the ammonium in the soil, the past commonly used distillation titration or colorimetric method, but the former lengthy procedures, the latter a larger error. In recent years, with the development of gas sensing electrodes, the ammonia electrode has been widely used to measure the nitrogen content in water or soil and plants. We tentatively made ammonia electrode, according to the preliminary application of the situation, the use of such electrodes, can achieve the purpose of rapid determination of ammonium in the soil in the field. First, the electrode manufacturing and determination methods