【摘要】 本文报道了全国21个省、市、自治区的14种土类的表土（0-15cm）103个样品和5个土壤剖面30个土样的全N含量及其δ¹⁵N值。为国内利用¹⁵N天然丰度估测生物因N₂量提供了基础资料。更多还原

【Abstract】 103 samples of surface soils （0-15cm） of 14 soil types from 21 provinces, autonomous regions and municipali ties and thirty samples of 5 profiles of 2 soil types at 2 sites were analysed for their total soil N contents and ¹⁵N natural abundance (δ¹⁵N value). The values of total soil N in 103 samples ranged from 250 to 4381ppm, the mean was 1337±797ppm. The δ¹⁵N values of them with respect to atmospheric N, ranged between+1.25-+22.97‰, the mean was 7.30±3.15‰, Relative frequency histogram of total soil N contents and δ¹⁵N values in surface soil samples did not show any normal distribution respectively. There was no correlation between total N content and δ¹⁵N values. δ¹⁵N values varied with depth, hut the variation of them was smaller than that of different locations at the horizon. The mean δ¹⁵N values in the most soil typeswere more than+5.00‰. But variation for δ¹⁵N values of the same soil type at different sites was great.The mean of δ¹⁵N values of Fluvio-aquic soils was the highest （+12.19‰）, and the lowest（+4.22‰） in yellow-brown soil. The mean δ¹⁵N value of total N of soil for grow ing crops, pastures, trees and native herbs were 6.80, 7.84, 7.88 and 9.98‰ respectively.更多还原