地木耳改变土壤含氮量的研究

将地木耳分别混于土壤中和置于土壤表面，让其进行作用，并与空白对照，取土样用常规扩散吸收法测其速效氮含量，结果表明，施用地木耳可增加土壤加的含氮量，证实它具有固氮作用，其中若无作物，混于土壤中比置于土壤表面含氮量增高明显，若有作物则正好相反。

A Study on the Influence of Nostoc commune on the Content of Nitrogen in Soil

The blue algae, Nostoc commune, were mixed with soil and put on the surface of soil to allow them to act. The results of these treatments were then compared with that of the control. The soluble nitrogen content of the soil was measured by means of the conventional diffusion-absorption method. It was shown that the application of Nostoc commune can increase the content of nitrogen in soil, which demonstrates its nitrogen-fixing ability. Without crops the magnitude of increase is more conspicuous in the mixing treatment than in the putting-on-the soil surface treatment while the oppesite case is true with crops.