盐渍土是我国重要的后备耕地资源，改良和利用盐渍土将为我国粮食安全提供重要保障。渤海湾滨海地区有着大量已开垦的盐渍土，经过几十年来排水洗盐等各种工程措施的改造，土体中的盐分已经降至较低水平。但当地盐渍土的质地黏重，团粒分散，结构不良等特点，使得在现有技术条件下土壤盐分难以进一步的降低，这不仅影响了有机物质在土壤中的分解循环，也限制了土地生产力和作物产量的提高。蚯蚓作为土壤动物群落的重要组成，在改良土壤方面发挥着“土壤生态工程师”的重要作用。然而由于土壤盐分是限制蚯蚓繁殖生长的重要因子，如何在盐渍化土壤中扩大蚯蚓种群以达到改善土壤结构、增加作物产量的目的，是滨海盐渍土改良研究中的重要理论和技术问题。对此，本文以位于渤海湾沿岸的河北省黄骅市中捷友谊农场十三队为研究点，开展了调控盐渍土中的有机物料和水分含量、改善盐渍土中蚯蚓生长繁殖的小环境条件、在一定盐分含量的盐渍土中接种蚯蚓并使之生长繁殖、监测土壤结构和盐分变化等相关研究，以期达到用生物方法改良滨海盐渍土的目的。 本文首先对研究区内不同农业土地利用类型和管理措施下土壤中的蚯蚓种群组成和密度进行了调查，掌握了当地主要蚯蚓种群的分布特点及其与土地利用类型和管理措施、土壤理化性质之间的关系，筛选出了可以用于接种繁殖的蚯蚓物种；在此基础上，通过室内实验验证了蚯蚓的生长繁殖在不同盐分水平的土壤中对有机物料质量（作物秸秆碳氮比）和土壤水分的响应及其机制；通过田间实验验证了有机物料类型（作物秸秆和粪肥）及覆膜的管理措施对蚯蚓生长和繁殖的影响及其机制；最后，分析了蚯蚓对盐渍土改造区的土壤大孔隙、土壤团聚体及土壤盐分的作用及效果。本文的主要结论如下： 1、在渤海湾滨海盐渍化农业土壤中存在3种蚯蚓：梯形流蚓（Aporrectodea trapezoides）、日本杜拉蚓（Drawida japonica japonica）、赤子爱胜蚓（Eisenia fetida），其中内生型蚯蚓梯形流蚓是优势种；该地区农业土地利用类型和管理措施影响了蚯蚓种群组成和密度；土壤有机质和全氮与蚯蚓种群密度和生物量成显著正相关。 2、室内调控有机物料质量（作物秸秆碳氮比）对梯形流蚓的生物量、蚓茧和幼蚓数量有显著影响。与施入小麦秸秆（高碳氮比）相比，施入苜蓿秸秆（低碳氮比）显著增加了成年蚓生物量（总鲜重和干重）和未成年蚓生物量，也显著增加了低盐分土壤中蚓茧和幼蚓数量。施用苜蓿秸秆提高了土壤微生物量碳（MBC）、土壤微生物量氮（MBN）、可溶性有机氮（DON）含量，可能为蚯蚓提供了更多的食物来源，促进了该地区土壤中梯形流蚓的生长繁殖。 3、田间调控有机物料类型（秸秆和粪肥）显著影响梯形流蚓的存活率和生物量。施用秸秆处理中蚯蚓存活率、蚯蚓鲜重和干重均低于施用粪肥的处理。在实验培养结束时（3.5个月），施用秸秆处理中的土壤MBC、MBN和DON含量与施用粪肥处理无显著差异，但施用粪肥处理中土壤真菌群落丰富度（OTUs、Chao1和ACE指数）显著高于施用秸秆处理，可能为田间条件下梯形流蚓提供了食物资源，促进了该类蚯蚓的存活和生长。 4、室内调控土壤水分显著影响了土壤中蚯蚓生物量、有环带的蚯蚓数量、蚓茧和幼蚓数量。较高的土壤水分（95%田间持水量）显著增加了蚯蚓总鲜重和干重。土壤水分对有环带的蚯蚓数量和蚓茧数量的影响取决于作物秸秆质量，较高的土壤水分显著增加了施用苜蓿秸秆处理中有环带的蚯蚓数量和蚓茧数量，对施用小麦秸秆处理无显著作用。在实验培养2个月和4个月时，较高的土壤水分显著增加高盐分土壤施用苜蓿秸秆处理中的蚓茧和幼蚓数量。田间覆膜调控措施增加了土壤含水量，但覆膜措施对蚯蚓存活率、总鲜重和干重没有显著影响。 5、蚯蚓活动增加了盐渍土改造区5-15 cm层土壤大孔隙度和大孔隙数量，且在施用秸秆处理中蚯蚓的作用显著；蚯蚓活动显著增加了施用粪肥处理中15-20 cm层土壤中大孔隙等效直径。蚯蚓活动能够增加0-10 cm层土壤大团聚体比例及其稳定性，并增加了20-30 cm层土壤大团聚体比例。 6、田间实验结果表明，蚯蚓活动使得不同土层的土壤盐分有降低趋势，尤其在施用粪肥处理0-10 cm土层中作用显著。

The saline soil spreading along the west coast of the Bohai Bay was regarded as the most potential cultivated land reserve for its relatively suitable water and heat conditions. With various technological architectures implemented over the past decades, the saline soil has been reclaimed to the low salinity which enabled the crop production. However, the degraded soil structure and the attendant problems caused by the leaching process, such as clay particle swelling and dispersion, decreased water infiltration and drainage, surface crusting and hardsetting, still make it difficult for further removing the salt, and thus impeding the decomposition of organic matters and leading to the limited crop production. Earthworms (Lumbricidae) are acknowledged as “ecosystem engineers” which play fundamental role in the ecological restoration and various degraded soils. However, the potential use of earthworms in the saline soil remediation was quite less known. A case study which aimed at increasing the earthworm population in the way of modifying the environmental condition- the food supply and the water content, and to achieve the role of the earthworms on the soil structure in the reclaimed saline soils was conducted on the west coast of Bohai Bay. The main objectives of this thesis were: (1) to investigate the earthworm species and populations characteristics in the coastal saline agriculture soils of varied land use practices, and the main factors affecting the earthworm populations; (2) to figure out the effect and mechanisms of organic materialsof varied qualities, soil water content and soil salinity on the growth and reproduction of the dominant earthworm species in the reclaimed saline soils; (3) to assess the impact of incorporating the organic materials of high quality and film covering on the earthworm growth and reproduction, and figure out its mechanisms in the field condition; (4) to evaluate the effect of earthworms on the soil macropore structure, the macroaggregates proportion and its stability, and the salt distribution in the profile. This research has the following findings: 1. Three earthworm species was found in the saline agriculture soils in the west coast of Bohai Bay, that is Aporrectodea trapezoides, Drawida japonica japonica and Eisenia fetida, and among them the endogeic earthworm Aporrectodea trapezoides is the dominated. The earthworm population density and biomass were significantly affected by the agriculture land use practices in the coast region. Significant positive correlationws were found between the soil organic matter, and the earthworm density and biomass, and so did the total nitrogen contents. 2. The biomass, the cocoons and the hatchlings of the endogeic earthworm Aporrectodea trapezoides were significantly affected by the qualities of organic residues of varied C/N ratio in the microcosm experiment. The total fresh biomass and dry weight of both adult and juvenile earthworms and the number of earthworms with fully developed clitellum were significantly higher in the application of low C/N ratio clover residues compared to the high C/N ratio wheat residues. This is also the same for the cocoons and the hatchlings at low soil salinity. The soil microbial carbon (MBC), soil microbial nitrogen (MBN) and the soil dissolved organic nitrogen (DON) were higher in the application of low C/N ratio clover residues compared to the high C/N ratio wheat residues, which might provide more food sources for the growth and reproduction of Aporrectodea trapezoides. 3. The organic materials types of high quality significantly affected the earthworm survival and growth in the reclaimed saline soils in the field condition. In the application of the plant residues, the earthworm survival, the earthworm fresh biomass and the dry weight were significantly lower compared to the application of manure. The soil MBC and MBN as well as the DON content were no significantly differences between the application of the plant residue and the manure, but the OTUs, the Chao1 and the ACE index of the soil fungus was significantly higher in the application of manure than the plant residue, which might provided more abundant food source and facilitated the earthworm survival and growth in the field condition. 4. The soil water content significantly affected the earthworm biomass, the number of earthworms with fully developed clitellum, the number of cocoons and hatchlings in the microcosm experiment. The high soil water content (95% Field Capacity, 95% FC) significantly increased the earthworm total fresh biomass and dry weight in the application of both low and high C/N ratio organic residues at both salinities. The high soil water content (95% FC) also increased the number of earthworms with fully developed clitellum in the application of low C/N ratio clover residue at both salinities, but not in the application of high C/N ratio wheat residue. The high soil water content (95% FC) increased the number of cocoons and hatchlings in the application of low C/N ratio clover residue at high salinity at 2 and 4 months. The soil water content was increased by film covering in the filed condition, but earthworm survival, total fresh biomass and dry weight were not significantly affected. 5. Earthworms’ activities in the reclaimed saline soils had increased the soil macroporosity and the macropore numbers in the 5 to 15 cm soil layer, but this effect was only significant in the application of plant residue. Earthworms’ activities significantly increased the mean size of macropores in the application of manure compared to the application of plant residue in the 15 to 20 cm soil layer. Earthworms’ activities increased the proportion and the stability of soil macroaggregates in the 0 to 10 cm soil layer, and as well as the proportion of soil macroaggregates in the 20 to 30 cm soil layer. 6. Earthworms’ activities had significantly decreased the soil electrical conductivity in the application of manure in the field condition, especially in the 0 to 10 cm soil layer.