湖北省几种主要土壤的固定态铵及其固定与释放的研究

Fixed-ammonium and Its Fixation and Release of the Major Upland Soils in Hubei Province

对湖北省几种主要旱地土壤用室内加氮培养和与植物物料混合于砂滤管田间培养进行试验研究 ,结果表明 ,湖北省耕地土壤固定态铵含量为 31.9～ 185 .3mg/kg ,占土壤全氮 5 .8%～ 2 3.7%。外源铵浓度为含N4 0 0mg/L时 ,土壤对铵的固定率为 33.0 %～ 5 0 .7% ;土壤近似最大固定态铵含量与土壤原固定态铵含量大小顺序一致。植物物料分解过程中土壤固定态铵含量的变化比交换性铵含量的变化更大 。

The experiments of N added incubation in lab and plant materials mixed in carborundum tube in field of typical upland soils in Hubei Province were conducted. The results showed that the soil fixed ammonium contents ranged from 31.9 mg/kg to 185.3 mg/kg,accounting for 5.8%～23.7% of total nitrogen in soil. The ammonium fixed ratios of the soils were 33.0%～50.7% when 400 mg/L N of ammonium solutions were added to the soils. The sequences of approximate soil maximal fixed ammonium contents were consistent with original soil ammonium contents. During the decomposition of organic materials in the soil, the fixed ammonium content changed greater than the exchangeable ammonium content. The fixed ammonium variation should be considered in calculating the plant material nitrogen mineralization rate.