盐碱地稻渔复合系统营养元素及其形态转化影响因子研究.

[Objective】 To understand the condition of water bodies of the rice-fishery complex systems in saline areas, the response relation- ships between nutrients and their morphological transformations and water environment factors were investigated. 【Method] From April to September 2021, water samples were collected at 35 sample sites, and 10 aquatic environmental factors and 6 forms of nutrients were deter- mined in the system. Correlation analysis, stepwise regression and path analysis, gray correlation analysis and redundancy analysis (RDA) methods were applied to study the relationships between nutrients and their morphological transformations and aquatic environmental factors. [Result】 The main factors affecting nitrogen of the rice-fishery complex system were alkalinity, CODMn, pH and water temperature in saline areas, the main factors affecting phosphorus were COD Mn, water temperature and alkalinity, and the main factors affecting total potassium were conductivity, TDS, Chl. a, alkalinity, salinity, CODMn and water temperature. Alkalinity, CODMn, pH and water temperature were the main factors affecting the transformation of nitrogen forms of the rice and fishery complex system in saline areas. CODMn, water tempera- ture, alkalinity, conductivity, salinity, Chl. a and pH were the main factors affecting the morphological transformation of phosphorus. There- fore, the main influencing factors of nutrient elements of the rice-fishery complex system were alkalinity, CODMn and water temperature in sa- line areas, and the main influencing factors of nutrient morphological transformation were alkalinity and pH. The main influencing factors of nutrient elements and their morphological transformation of rice-fishery compolex system were relatively consistent in saline areas, the main factors were alkalinity, CODMn, pH and water temperature, among which CODMn was positively correlated with nutrients. and water tempera-ture was negatively correlated with nutrient elements. Alkalinity and water temperature mainly inhibited the rise of nutrient elements, while COD Mn could promote it. [Conclusion] The water temperature of the rice-fishery compolex system is suitable in saline areas, and the salinity can improve the alkalinity of the water body, which has a positive effect on inhibiting the increase of nutrient content, but with the operation of the system, COD Mn will increase, and certain measures need to be taken if CODMn increases excessively. [ABSTRACT FROM AUTHOR]