2.1 Site description
The study location was situated in Tiaozini reclamation area in Dongtai prefecture (32°49.9′ ~ 32°50.3′N, 120°56.6′ ~ 120°57.4′E), north Jiangsu Province, China (Fig. 1). This site was located in marine-terrestrial interlaced area and was enclosed and reclaimed from coastal tidal mudflats in 2013. The distance from this site to the coastline of China Yellow Sea was about 1.6 km (Liu et al., 2019). The experimental site has nearly flat topography with an average elevation of 1.0 m above-sea-level. This site was in subtropical zone and strongly affected by the oceanic monsoon throughout the year. Cold, dry season is from November to March and the hot, wet season is during June and September. The mean annual rainfall is 1048.5 mm and an average of 734.3 mm rainfall occurred from May to September during the period of 2000-2015. Annual air temperature and daily sunshine duration were averagely 15.0 ℃ and 5.8 h, respectively. Developed from Yangtze alluvial sediments and marine sediments, the predominant soil is silt loam, classified as a loamy, mixed Typic Halaquepts group of Aquepts in Inceptisols based on soil taxonomy (Soil Survey Staff, 2014). Shallow saline water table (annual average electrical conductivity of 7.6 dS/m and water table of 1.10 m) results in large areas of salt-affected land and poor soil productivity for cropland. The experimental site is a representative of large areas of salt-affected farmlands in coastal alluvial plain of China.
Figure 1