不同有机物料施用对含盐土壤中蚯蚓生长、繁殖和活性的影响及机理研究

Earthworms are commonly referred to as soil ecosystem engineers for their ability to modify soils and plant communities. Soil salinization of arable lands adversely affects soils physical, chemical and biological properties and reduces the population of earthworms. Based on this current status, we hypothesized that agricultural organic residues could reduce negative effects of soil salinity on the growth, reproduction and activities of the earthworm related their comminution, feeding, burrowing casting and bioturbating activities, which may be due to the improvement of food resources and soil environmental conditions. The aim of the present study was to determine the effects of different organic residues on the growth, reproduction and activities of earthworm and the interaction of between earthworm and food resources and soil environmental conditions in salt-affected soils in a laboratory experiment. Through these studies, it is to expect that the research findings will show the mechanism of the effects of different organic residue application on the growth, reproduction and activities of earthworms. If we understand the role of different agricultural organic residues in earthworm succession, we will be able to improve their role in salt-affected soil restoration and soil management.

针对农田土壤的盐渍化导致"土壤生态工程师"-蚯蚓种群数量减少的现状，提出在一定含盐土壤条件下，农业有机废弃物料提供高效食物资源，改善土壤环境条件，促进蚯蚓的生长、繁殖和活性以及相关的取食和排泄活动。本研究以渤海湾西岸滨海地区盐渍化农田土壤以及其中的优势蚯蚓种群为对象，以蚯蚓的生长、繁殖和活性的变化为主线，利用室内控制培养实验，研究不同有机物料施用对含盐土壤中蚯蚓生长、繁殖和活性的影响，分析含盐土壤中蚯蚓食物资源量、土壤通透性和渗透压与蚯蚓生长、繁殖和活性之间的关系，阐明有机物料提供高效食物资源，改善土壤通透性和渗透压促进含盐土壤中蚯蚓生长、繁殖和活性的机制。通过上述研究，预期研究结果有助于揭示不同有机物料施用对含盐土壤中蚯蚓生长、繁殖和活性的影响及机理；并为盐渍化农田土壤肥力恢复和提升过程中农业有机废弃物和有益土壤生物的发掘和合理利用奠定基础。

盐渍化农田土壤中作物秸秆施入和土壤水分调控，能增加盐渍化农田土壤中大型土壤生物种群数量，进而进一步加快盐渍化农田土壤生态肥力提升。项目通过不同质量（C/N比）作物秸秆还田和调控水分，研究盐渍化农田土壤中蚯蚓生长和发育的特征、蚯蚓的繁殖特征以及蚯蚓食物资源和土壤化学性状的特征。结果表明，与高C/N比小麦秸秆比较，低C/N比苜蓿秸秆施入含盐土壤中显著增加含盐土壤中蚯蚓总鲜重和干重，促进未成蚯蚓发育，形成环带；与高C/N比小麦秸秆比较，低C/N比苜蓿秸秆有显著高的蚓茧和幼蚓的数量；与高C/N比小麦秸秆比较，低C/N比苜蓿秸秆施入增加含盐土壤微生物量和土壤可溶性有机氮浓度；同时，在低C/N比苜蓿秸秆施用下，高土壤水分能够增加有环带蚯蚓的数量；在低C/N比苜蓿秸秆施用下，高土壤水分能够增加土壤可溶性有机碳。作物秸秆施入含盐土壤中，在分解初期能够降低整个土体的土壤电导率，可能有利于蚯蚓生长和发育。结果可为盐渍化农田土壤中大型土壤动物种群的增加提供科学依据，也为盐渍化农田土壤生物修复奠定基础。