Abstract:Abstract: Due to the extensive use of chemical fertilizers in agriculture in southern China, the utilization rate of phosphorus is low and the agricultural non-point source pollution is serious. The ecological ditch is an important measure to intercept nitrogen and phosphorus pollution from agricultural non-point sources. Influenced by the characteristics of ecological ditches and environmental factors, the removal efficiency of ecological ditches in different studies varies greatly. Through the literature retrieval platform CNKI and Web of Science, relevant literatures on the migration and transformation process of phosphorus in ecological ditches were collected. After screening under the following conditions (dynamic experiments, outdoor single ecological ditches, etc.), a database of ecological ditches was established, which contained a total of 81 experiments and 334 items of data. Statistical analysis showed that the average removal efficiency of Total Phosphorus (TP) by ecological ditches was 47.16%. Based on the Mann-Whitney U test and K-W test, the effects of different factors (vegetation type, ditch material type, strengthening measures, climate temperature, and hydraulic retention time) on the TP removal efficiency of ecological trenches were analyzed. The results showed that there were significant differences in the TP removal efficiency of ecological ditches covered with different vegetation. The TP removal efficiency of ecological ditches covered with selected vegetation was better than that of ecological ditches covered with natural vegetation, and the average removal efficiency was 47.97%. The TP removal efficiency of ecological ditches covered with different detailed vegetation types was different. The TP removal efficiency of ecological ditches covered with various selected vegetation was significantly higher than that of ecological ditches covered with single selected vegetation, various natural vegetation and single natural vegetation, and the average removal efficiency was 53.93%. There were significant differences in the TP removal efficiency of ecological ditches with different material types. The TP removal efficiency of semilined ecological ditches was better than that of soil ecological ditches, and the average removal efficiency was 51.04%. The TP removal efficiency of different semilined ecological ditches was different. The TP removal efficiency of the ecological ditches with semilined slope was better than that of the ecological ditches with fullylined slope and the ecological ditches with semilined slope and bottom, and the average removal efficiency was 58.22%. There were significant differences in the TP removal efficiency of ecological ditches with different reinforcement measures. The TP removal efficiency of ecological ditches with artificial substrate was significantly better than that of the ecological ditches with interception, and the average removal efficiency was 53.53%. There were significant differences in the TP removal efficiency of ecological ditches in different climate temperature ranges. The TP removal efficiency of ecological ditches with climate temperature ranging >25-35 °C was significantly better than that of ecological ditches with climate temperature ranging 0-15 and >15-25 °C, and the average removal efficiency was 57.18%. In different hydraulic retention time ranges, the TP removal efficiency of ecological ditches with hydraulic retention time over 24 h was better than that of ecological ditches with hydraulic retention time ranging 0-12 and >12-24 h, and the average removal efficiency was 72.12%. The research results of this paper can provide technical support for the assessment of phosphorus interception effect in ecological ditches and the design of ecological ditches.