NaCl and Na₂SO₄ are the key factors affecting nitrogen (N) mineralization in the soil of estuarine wetlands. However, it remains unclear how N mineralization responses to NaCl and Na₂SO₄. In the present study, samples of topsoil (0–10 cm) and subsoil (10–20 cm) were collected in three marshes, including a Phragmites australis marsh (Pa-marsh), a Suaeda salsa marsh (Ss-marsh) and a mudflat marsh (Mu-marsh), in the Liaohe River estuary. The soil samples were treated by NaCl and Na₂SO₄, with a set of salinity levels of 0 %Es, 2 %Es, 5 %Es, 10 %Es, 20 %Es and 100 %Es (%Es, percent of equivalent seawater), respectively. After incubating the soil samples for 2 weeks, the contents of NH₄⁺N and NO₃⁻N were measured and the net N mineralization rates (R_min) were calculated. We found that NH₄⁺N and NO₃⁻N accumulations in the soil samples of the three marshes in the NaCl and Na₂SO₄ treatments. Both NaCl and Na₂SO₄ significantly affected R_min for the top soil for Pa-marsh in all salinity treatments, whereas salt-effects for Ss- and Mu-marsh soils were only found at 10 %Es and/or 20 %Es levels in the NaCl treatments. There was an ion-specific effect of NaCl and Na₂SO₄ on N mineralization. NaCl increased R_min by 114–164% and 86–139% in the topsoil and subsoil of the three marshes, respectively; Na₂SO₄ increased R_min by 234% in the topsoil of Pa-marsh and had no effect on R_min in the other soils. A salt threshold of 50–60%Es was found for NaCl and Na₂SO₄ impacting on N mineralization of Pa-marsh soil. Salt type, salinity level, wetland type and soil layer were the main factors impacting the N mineralization. The results suggest that the effect of salt on N mineralization could vary with salt type and soil properties.

NaCl和Na ₂ SO ₄是影响河口湿地土壤中氮（N）矿化的关键因素。然而，目前尚不清楚氮矿化对NaCl和Na ₂ SO _4的反应如何。在本研究中，在三个沼泽地中收集了表层土壤（0–10 cm）和地下土壤（10–20 cm）的样本，其中包括芦苇沼泽（Pa-marsh），苏阿萨尔萨斯沼泽沼泽（Ss-marsh）和滩涂沼泽（Mu-marsh），位于辽河河口。用NaCl和Na ₂ SO ₄处理土壤样品，其盐度水平分别为0％Es，2％Es，5％Es，10％Es，20％Es和100％Es（％Es，当量海水的百分比）。将土壤样品孵育2周后，测量NH ₄ ⁺ N和NO ₃ ^- N的含量，并计算净氮矿化率（R _min）。我们发现，在NaCl和Na ₂ SO ₄处理的三个沼泽地的土壤样品中，NH ₄ ⁺ N和NO ₃ ^- N积累。NaCl和Na ₂ SO _4均显着影响R _min在所有盐度处理中，Pa沼泽的表层土壤的盐分效应均存在，而在NaCl处理中，Ss和Mu沼泽土壤的盐效应仅在10％Es和/或20％Es的水平下发现。NaCl和Na ₂ SO ₄对N矿化具有离子特异性作用。在三个沼泽的表层土壤和下层土壤中，NaCl的R _min分别增加了114–164％和86–139％。Na ₂ SO ₄在Pa沼泽表层土壤中的R _min增加234％，而对其他土壤中的R _min无影响。发现NaCl和Na ₂ SO _4的盐阈值为50–60％Es对Pa沼泽土壤氮矿化的影响 盐分，盐度，湿地类型和土壤层是影响氮矿化的主要因素。结果表明，盐分对氮矿化的影响可能随盐分类型和土壤性质而变化。