『Abstract
　Electrical conductivity of saturated soil extracts (ECe) in three reclaimed tideland (RTL) soils on the west coast of Korea decreased with time since reclamation, indicating natural desalinization through leaching of salts by precipitation water. Soil N concentration increased with decreasing ECe. With the increase in soil N concentration, the δ¹⁵N decreased, likely caused by the input of ¹⁵N-depleted N sources. As N2-fixing plant species were found in the oldest RTL, atmospheric N2 fixation likely contributed to the increase in soil N concentration in the oldest RTL. Negative δ¹⁵N (-7.1 to -2.0‰) of total inorganic N (NH4⁺ + NO3^-) and published data on N deposition near the study area indicate that atmospheric N deposition might be another source of N in the RTLs. meanwhile, the consistently negative δ¹⁵N of soil NO3^- excluded N input from chemical fertilizer through groundwater flow as a potential N source, since NO3^- in groundwater generally have a positive δ¹⁵N. The patterns of δ¹⁵N of NH4⁺ (+2.3 to +5.1‰) and NO3^- (-9.2 to -5.0‰) suggested that nitrification was an active process that caused ¹⁵N enrichment in NH4⁺ but denitrification was probably minimal which would otherwise have caused ¹⁵N enrichment in NO3^-. A quantitative approach on N budget would provide a better understanding of soil N dynamics in the studied RTLs.

Keywords: Atmospheric N deposition; N2 fixation; ¹⁵N natural abundance; Saline soil; West Korea』

Introduction
Materials and methods
　Study site
　Soil sampling and chemical analyses
　Calculations and statical analyses
Results
　ECe and N concentration of soils
　δ¹⁵N values and their relationship with N concentration
Discussion
　ECe and N concentration of soils
　δ¹⁵N, potential N sources, and N transformations
Conclusions
Acknowledgment
References