Determination and Application of ¹⁵N Abundance in Sorghum

In order to investigate the effects of different kinds of fertilizer on nitrogen isotope composition of sorghum, the plants were cultivated according to organic and conventional agriculture. The method of determining nitrogen stable isotope ratio (δ¹⁵N) of sorghum was established using stable isotope ratio mass spectrometer (IRMS). Nitrogen isotope ratios（δ¹⁵N values）of sorghum fruits were determined. The result shows that the δ¹⁵N values of sorghum are closely related with the kinds of fertilizer applied during the plant’s growth time. The δ¹⁵N values of organic sorghum are often higher than those of conventional ones. The δ¹⁵N values of sorghum can provide a reference for tracking kinds of fertilization applied on sorghum plants.