Effect of Puccinellia Tenuiflora Growth on Nitrogen Content of Alkalized Soil in Song-Nen Plain

The total nitrogen content, alkali-soluble nitrogen content, ammonification intensity, nitrogen fixation intensity, urease activity, protinase activity, nitrite reductase activity and nitrate reductase activity of alkalized soil of which Puccinellia tenuiflora grown for different years increased that compared with alkali spot soil, and there are difference between the soil of which P. tenuiflora grown for different years. The total nitrogen content of the soil of which P. tenuiflora grown for different years has significant difference with alkali spot soil, and the alkali- soluble nitrogen content of the soil of P. tenuiflora grown for three or four years has significant difference with alkali spot soil, but the ammonification intensity, nitrogen fixation intensity, urease, proteinase, nitrite reductase and nitrate reductase activity of alkalized soil of which P. tenuiflora grown for three, four or five years have the significant difference with that of alkali spot soil. All of above indicated that the growth of P. tenuiflora has the improvement effect upon nitrogen nutrition status of alkalized soil, and which grown for 3~5 years is the best of all.