Correlation Among Fine Root Standing And Median Root Lifespan Of Cartagena Korskinskii And Content Of Available Nitrogen In Soil

There were amount of fine root of cartagena korskinskii, which play an important role in the minerals circle in ecological system. The fine root standing and median lifespan of cartagena korskinskii seedlings in a five years old plantation in Loess Plateau area, Northwest Shanxi, was investigated using minirhizotron technique, a little destroyed method for study of root system. The object of the study was the correlation of RLDst in Match 2008 to September, MRL, RLDgr, RLDdr and the content of available nitrogen.(1) The vertical feature of RLDst of Cartagena Korskinskii in different soil layer showed: RLDst in deeper soil (40～100cm) existed more than in upper soil (0～40cm). The maximum of RLDst appeared in 70～80cm depth. There were not vertical correlation between RLDst and NH+-N in soil, but it presented negative correlation among RLDst and the content of NO3--N and available nitrogen. The seasonal correlation of RLDst of cartagena korskinskii in different seasons showed:the maximum of RLDst papered on Aug.20. There were not seasonal correlation between RLDst and the content of NH+-N and NO3--N and available nitrogen.(2) The vertical feature of MRL of cartagena korskinskii in different soil layer showed:there were shorter MRL exited in surface soil (O～10cm) than in deeper soil (90-100cm). The seasonal feature of MRL of cartagena korskinskii in different soil layer showed: there were shorter lifespan and higher mortality rate among roots bored in spring than in summer, MRL in autumn did not appear in observation time. It presented significant positive seasonal correlation between MRL and the content of available nitrogen. However, there were significant negative vertical correlation between MRL and the content of available nitrogen.(3) The study showed that RLDgr of cartagena korskinskii faster in under soil than in upper soil. The soil layer of maximum of RLDgr of cartagena korskinskii was 70-80cm. It presented obviously positive vertical correlation between RLDgr and the content of available nitrogen and NO3--N. The seasonal feature of RLDgr in different seasons showed that RLDgr attach to a peak in summer. The time of maximum was on June 26 to July 21. However, there is no seasonal correlation during observation time.RLDdr of cartagena korskinskii was faster in upper soil than in under soil. The soil layer of maximum of RLDdr of cartagena korskinskii was 0～30cm. It presented obviously positive vertical correlation between RLDdr and the content of available nitrogen. The seasonal feature of RLDdr in different seasons showed that the time of maximum was on Sep.21 to Oct.20. There was seasonal negative correlation between RLDdr and the content of NO3--N and available nitrogen.