College of Agricultural Science and Engineering, Hohai University, Nanjing, 210098, China.
Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Science and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
Chemosphere. 2024 Oct;366:143427. doi: 10.1016/j.chemosphere.2024.143427. Epub 2024 Sep 26.
The ecological construction in coastal saline-alkali areas urgently needs to be explored in terms of water-salt regulation management and functional irrigation. In this paper, the extremely severe saline soil in the eastern coastal area of the North China Plain was selected for vegetation rehabilitation by drip irrigation. Through two-year field experiments, the spatial and temporal soil salinity-water dynamics of three land use types (LUTS) under two irrigation strategies (IIS) were systematically studied. The results revealed: (1) The soils in the understory grassland and shrub land root zones remained stable for desalination, with the average ECe decreasing to 0.69 dS/m and 0.71 dS/m under autumn irrigation at surface, and 0.66 dS/m and 0.85 dS/m under winter irrigation. And a slight salt accumulation occurred in the bare land in stage IV. (2)The soil surface moisture increased, and the bulk density decreased significantly with drip irrigation. The final moisture of understory grassland and shrub land was 3.85 and 2.97 times that of the bare land layer at 0-10 cm, 2.55 and 1.97 times at 10-20 cm, and 1.61 times and 1.47 times at 20-40 cm, respectively. (3)Due to quick salt rinsing, Salix matsudana and Hibiscus maintained a high survival rate, and the germination of understory vegetation further increased the vegetation coverage. Meanwhile perennial understory herbs gradually became the dominant species, which positively effects on the maintenance of soil low-salt environment. (4)There were significant differences in SWC and ECe between autumn and winter irrigation treatment during stage I and stage II, indicating that irrigation strategies only impact on soil water-salt movement in the early stage. While there was no significant difference between understory grassland and shrub land, indicating that the research about the effects of vegetation cover type on water-salt transport should take a longer time scale.
滨海盐碱地区的生态建设迫切需要在水盐调控管理和功能灌溉方面进行探索。本研究选择华北平原东部滨海地区极度盐碱化土壤，采用滴灌技术进行植被修复。通过两年的田间试验，系统研究了两种灌溉策略（IIS）下三种土地利用类型（LUTS）的时空土壤盐分-水动态。结果表明：（1）在地表秋季灌溉和冬季灌溉条件下，林下草地和灌丛地根区土壤脱盐稳定，平均 ECe 分别降至 0.69 和 0.71 dS/m；而裸地在第四阶段出现轻微盐积累。（2）滴灌后土壤表面水分增加，容重显著降低。林下草地和灌丛地 0-10 cm 层最终含水量分别为裸地的 3.85 倍和 2.97 倍，10-20 cm 层分别为 2.55 倍和 1.97 倍，20-40 cm 层分别为 1.61 倍和 1.47 倍。（3）由于盐分的快速淋洗，柳树和木槿保持了较高的成活率，林下植被的萌发进一步增加了植被覆盖率。同时，多年生草本植物逐渐成为优势种，有利于维持土壤低盐环境。（4）在阶段 I 和阶段 II 中，秋季和冬季灌溉处理之间的 SWC 和 ECe 存在显著差异，表明灌溉策略仅在早期阶段影响土壤水盐运移。而林下草地和灌丛地之间没有显著差异，表明关于植被覆盖类型对水盐传输影响的研究应该考虑更长的时间尺度。
