北方滨海地区地下水矿化度高、水位埋藏浅，受季风气候的影响，春、秋季土壤蒸发强烈，矿化度高的地下咸水随土壤孔隙上升，易造成土壤的积盐和返盐，导致该地区土壤多为盐渍土。由于该区可利用的土地资源短缺，因此提高土地利用率，改善土地质量变得极为重要，盐渍土作为一种后备的土壤资源亦被广泛看好。盐渍土改良有很多措施，最有效的盐渍土的改良措施是排水洗盐。科学家们就地取材，利用滨海地区丰富的地下咸水资源对盐渍土进行改良，已经取得了很好的进展。针对地下水位高的问题，通过建造台田-浅池系统，相对降低地下水位，在冬季浅池咸水结冰后，将微咸水冰破碎、采集并覆于台田上。重力作用下咸-淡分离的微咸水冰的液态水分梯次入渗，不仅能提高土壤含水量，还能降低土壤盐度。在碱化土壤中加入钙元素可以提高植物在盐分胁迫下的抗逆性。本文主要研究在小区试验条件下，台田覆冰灌溉结合改良剂（脱硫石膏）对滨海台田盐渍土壤水、盐动态分布的影响；覆冰灌溉结合改良剂对台田盐渍土壤盐分离子组成的影响；覆冰灌溉结合改良剂对台田盐渍土壤养分和作物生长的影响。结果表明：（1）覆冰灌溉能显著增加台田盐渍土0-80cm的含水量，且覆冰量越大土壤含水量增加越多，改良剂对土壤含水量没有显著影响。无论是否施用土壤改良剂，两年覆冰灌溉处理都显著降低台田0-20cm层的土壤盐度。在春季覆冰融化后，土壤改良剂施用显著增加了台田0-60cm层土壤盐度；在作物收获后，土壤改良剂施用对台田各层土壤盐分没有显著影响。两年后，台田各处理（除对照外）0-40cm层土壤盐度都低于2 g/kg；覆冰灌溉和施用改良剂对台田深层土壤（60-100cm层）盐度没有影响。（2）覆冰灌溉降低台田0-20cm层土壤Na+ 和Cl- 含量；改良剂的施用则增加了台田0-20cm层土壤Ca2+的含量，降低了土壤Na+的含量。无论是否施用土壤改良剂，覆冰灌溉显著增加台田0-40cm层土壤pH。土壤改良剂施用显著降低台田0-60cm层土壤pH。作物收获时，台田所有处理0-100cm层土壤pH显著增加。（3）覆冰融化（第一年）能够降低台田0-20cm层土壤钠吸附比（SAR）（p<0.005），土壤改良剂施用一年后（2012年10月）能够增加深层土壤SAR（p<0.05）。第二年作物收获时，土壤改良剂降低了台田0-100cm层土壤SAR，但显著性表现在0-20层土壤上（p<0.005）。覆冰灌溉（第一年）显著降低台田0-20cm层土壤碱化度（ESP）；作物收获时（两年），改良剂显著降低了（p<0.001）台田0-20cm层土壤ESP。（4）覆冰融化（无改良剂施用）使得台田0-20cm层土壤速效磷浓度降低43.1-90.7%（p<0.001）；无论是否施用改良剂，覆冰灌溉显著降低台田0-40cm层土壤硝态氮浓度，但0-20cm层土壤氨态氮浓度增加19.8%。两年后的结果显示，覆冰量高（8000m3/ha）比覆冰量低（4000m3/ha）更能增加台田0-40cm层土壤的有效磷和无机氮浓度速效钾含量。总之，北方滨海地区冬季覆冰灌溉能够在增加土壤含水量的同时降低台田表层土壤盐度、SAR和ESP；改良剂施用降低0-100cm土壤pH、SAR和ESP；覆冰灌溉和改良剂对土壤养分有积极影响。因此，在北方滨海地区，覆冰灌溉结合改良剂对台田盐渍土改良能取得较好的改良效果。

Due to the shallow water table, high salinity groundwater and monsoon climate in the northern coastal area, soils in this area are mostly low productive saline soil. However, this area has a large population and small per capital land, so saline soil was seen as a good prospects resource to solve the land shortage problem.There are many measures to improve saline-alkali soil. Irrigation and drainage were considered the most effective measures. However, the study area is short of fresh water, so we need to find a new alternative source of water. Many scientists have proposed to use the underground saline water resources to substitute the fresh water. While considering the water table is shallow, researchers bring “raised land-shallow pond” system forward to lower the groundwater table relatively. After the saline water was frozen in the shallow pond, we broke the brackish ice and applied it on the man-made raise bed. Salty water isolated first because of gravity, then the fresh water. In this way, brackish ice application can reduce soil salinity while improve soil moisture. As brackish ice will lead the soil to alkalization, calcium can be added to reduce soil alkalization and increase plant resistance under salt stress.This essay studies the impact of brackish ice and FGD gypsum on soil water content, salt content, soil pH, SAR, ESP, soil nutrients, plant growth and production. The results showed that: (1) The application of brackish ice significantly increased the soil water content in the 0-80cm soil layers. The more brackish ice, the higher water content. FGD gypsum had no significant effect on soil water content. Brackish ice application can decrease the salinity of 0-20 soil layer with or without FGD gypsum. The FGD gypsum increased soil salinity in the 0-60cm soil layers during brackish ice melting. After treatments, soil salinity are lower than 2 g/kg. Both brackish ice and FGD gypsum application had no effect on the deeper soil salinity in the raised bed.(2) Brackish ice application deceased Na+ and Cl- content in the 0-20cm soil layer while FGD gypsum increased Ca2+ content but decreased Na+ content in the top layer soil. Brackish ice increased soil pH in the 0-60cm soil layer with or without FGD gypsum while FGD gypsum application decreased salinity in the 0-40cm soil layers in the raised bed. After two years’ treatment, pH of all treatments increased.(3) Brackish ice application decreased soil sodium adsorption ratio (SAR) and exchangeable sodium precentage (ESP) in 0-20cm soil layers (p<0.005) during brackish ice melting, while FGD gypsum increased soil SAR in the deeper soil layers (p<0.05) in the first year treatments. Two years later, FGD gypsum decreased soil SAR in 0-100cm soil layers, while significance showed in the 0-20cm soil layers (p<0.005). After two years’ experiment, FGD gypsum decreased soil ESP in the 0-20cm soil layers (p<0.05) comparing to treatments that didn’t treat with gypsum.(4) Brackish ice melting decreased the available P content by 43.17 % and 90.71 % (p<0.001) in the 0-20-cm soil layer compared to the control treatment. The application of brackish ice reduced NO3-N content (p<0.05) in the 0-40-cm soil layers compared to the control treatment to which brackish ice was not applied, regardless of FGD gypsum incorporation. The application of high volume (8,000 m3/ha) brackish ice increased the NH4-N content of the 0-20-cm soil layer by 19.88 % compared to the control treatment. The application of high volume (8,000 m3/ha) brackish ice increased available K in the 0-20-cm soil layer than the treatments with lower volume (4,000 m3/ha) of brackish ice, regardless of FGD gypsum incorporation after two years treatments.In all, the application of brackish ice decreased soil salinity , SAR and ESP while increased soil water content and pH in 0-20cm soil layers. The application of FGD gypsum decreased soil pH, SAR and ESP. Bracksish ice may have the potential to increase soil nutrients. Thus, the application of brackish ice and FGD gypsum can improve saline-sodic soil property in coastal China.