Effect of nitrogen fertilizer on wheat uptake of soil N in a pot experiment

A pot experiment was conducted to determine the effect of nitrogen fertilizer on the uptake of soil native N and fertilizer N by spring wheat using N-15 isotopic dilution method. The results showed that fertilizer N addition restrained the uptake of soil N via a negative added nitrogen interaction (ANI), and the effect being more at higher rates of application. Additionly, fertilizer N increased the uptake of fertilizer N by wheat, in which grain uptook most of the nitrogen, followed by straw and root. The nitrogen use efficiency (NUE) ranged from 27%similar to 51%, while 36%similar to 63% of the fertilizer-N remained in soil ready for successive crop growth.