Abstract
The study of soil nitrogen transformations, both under laboratory conditions and in situ, requires a large number of time consuming and expensive chemical analyses. In this paper we present a possible alternative to chemical analysis when monitoring N dynamics. Time domain reflectometry (TDR) allows simultaneous monitoring of soil moisture content and bulk soil electrical conductivity (EC). In non-saline soils the nitrate ion plays an important part in the changes of soil solution electrical conductivity over time. We used the strong correlation between NO3--N concentration and EC for on-line monitoring of the mineralization process in two soils with different mineralization potential. Agreement between measured and TDR calculated NO3--N concentrations were good. The observed discrepancies between measured and calculated NO3--N concentrations can be explained by the influence on the EC of other anions, mainly SO42- and HCO3. In a second experiment we used TDR to monitor the immobilisation of native and added NO3--N in soil with addition of glucose. The TDR calculated NO3--N concentrations showed a strong immobilisation of N in the first 2-3 days, followed by a gradual remineralization. From the results presented here it can be concluded that TDR has potential to monitor soil N transformations, especially under controlled environmental conditions such as in laboratory incubation studies.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
