A Study On The Characteristics Of Ammonium Fixation And Adsorption Of The Corn Belt Phaeozem In Songliao Plain

The supply condition of nitrogen is one of the important targets to judge the fertility in soils . The supply condition of nitrogen , the different forms of nitrogen and their transformation ,. the fixation and adorption of ammonium are important parts of nitrogen recycle in soils , keeping and improving soil fertility and using nitrogenous fertilizer in reason according as them .The research by using the method of chief of field sampling, laboratory incubation and analyses to investigate the different forms of nitrogen ,the content of fixed ammonium, capacity of fixing-ammonium in black soils ,the maximum capacity of fixing-ammonium and their affect factors,kinetics of soils ammonium fixation and release of fixed ammonium ,ammonium adsorption and desorption in order to definite characteristics of Ammonium Fixation and adsorption of the Corn Belt Phaeozem in Songliao plain and realize the reserves of fixed ammonium in black soil, the capability of the fix nitrogen fertilizer,ammonium fixation and release of fixed ammonium Consequently forecast the capacity of keeping nitrogen to the purpose of affording guidance to utilize fertilizer availability. The main results were as follows:1. The total N of cultivated horizon in the Corn Belt Phaeozem in Songliao plain ranged from 0.136% to 0.292%, the average is 0.204% .Nitrate nitrogen ranged from 2.4 to 11.28 mg/kg with an average of 4.13 mg/kg, Fixed ammonium content in soil samples studied ranged from 60.2 to 210 mg/kg with an average of 146.9 mg/kg,,which accounted for 4.04%～12.46% of the total N and accounted for 75.59%～97.76% of abio-nitrogen. Amino acid-N ranged from 250.23 mg/kg to 474.37mg/kg with an average of 368.77mg/kg,, which accounted for 23.3% of the total N. ammonia-N ranged from 250.23 mg/kg to 474.37mg/kg with an average of 347.89 mg/kg, which accounted forl5.8%～30% of the total N, the average is22%;amidosuger-N ranged from 3.0 mg/kg to 67.6 mg/kg with an average of 18.27 mg/kg. The soil factors affecting fixed ammonium content in soils tested were mainly parent material, soil clay composition, the content of clay (< 0.01 mm ) and CEC .2. The capacity and maximum capacity of fixing-ammonium in the cultivated horizon ranged from 42.98 mg/kg to59.83 mg/kg and 160.4 mg/kg to 273.15mg/kg, respectively, with an average of 87.66 mg/kg and 230.11 mg/kg . Nowadays, at the condition of fertilize once system the black soils fix ammonium ranged from 142.28kgN / ha to 242.19kgN / ha . The soil factors affecting the capacity of fixing-ammonium in tested soils were mainly CEC and concentration of NH₄⁺ in soil.