In a 0~50cm depth,the content of total N(y) has obvious linear relation with the content of organic matter(x)(y=0.0278+0.05x,R2=0.9524). In a 50~170 cm depth,it shows exponential relation(y=0.0659e0.3126x,R2=0.904).

• 在0~50 cm土层；塔河下游土壤全氮(y)与有机质(x)之间的最佳模型为线性模型；方程为y=0.；0278+0