Uptake and Release of Sequestered Nutrient in Subtropical Monsoon Ecological Ditch Plant Species Mathieu Nsenga Kumwimba & Mawuli Dzakpasu & Bo Zhu & Diana Kavidia Muyembe Received: 17 May 2016 /Accepted: 3 October 2016 # Springer International Publishing Switzerland 2016 Abstract Ecological ditches have demonstrated the ability to filter and control nutrient transport to rivers. Few studies, however, have examined the internal loading of nitrogen (N) and phosphorus (P) in these systems due to vegetation decomposition. Most often, this concept is overlooked during evaluation of the nutrient removal rate of the ditches. Thus, the litter bag technique was used to analyze nutrient release to surface water during these processes. Mesocosm and field experiments were conducted to assess the growth characteristics and consequent nutrient accu- mulation by six ditch plant species. Of the six, Canna indica had the highest aboveground accumulation of N and P. About 85–95 % increase in the aboveground biomass was recorded at the end of the experimental period. The removal efficiencies of TN, TP, and NH 4 - N from the sewage reached up to 72–99.4, 64–98.7, and 75 %–100, respectively. Complete removal of all NO 3 -N was achieved. The amounts of N and P uptake by plant species were closely related to the biomass of plants. During the decaying process, N and P concentrations in the aboveground biomass decreased. These lost nutrients were eventually shifted to the system, which led to a deterioration of the water quality. Therefore, harvesting of aboveground biomass from inside the ditch is an appropriate inter- vention to prevent the release of N and P in the dormant season. The finding is important for planning an efficient eco-ditch system and predicting the influ- ence of nutrient loading in the eco-ditches upon se- nescence of ditch plants. Keywords Eutrophication . Decomposition . Non-point source pollution . Eco-ditch water quality . Accumulation . Aboveground senescence 1 Introduction Fluxes of nitrogen (N) and phosphorus (P) to rivers and reservoirs have significantly increased in recent decades Water Air Soil Pollut (2016) 227:405 DOI 10.1007/s11270-016-3105-7 M. N. Kumwimba : B. Zhu Key Laboratory of Mountain Surface Processes and Ecological Regulation, Chinese Academy of Sciences, 610041 Chengdu, China M. N. Kumwimba : B. Zhu Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, 610041 Chengdu, China M. N. Kumwimba : B. Zhu (*) University of Chinese Academy of Sciences, Beijing 100049, China e-mail: bzhu@imde.ac.cn M. N. Kumwimba Faculty of Agronomy, Department of Natural Resources and Environmental Management, University of Lubumbashi, PO Box 1825, Lubumbashi, Democratic Republic of Congo M. Dzakpasu UCD Dooge Centre for Water Resources Research, School of Civil Engineering, University College Dublin, Newstead Building, Belfield, Dublin 4, Ireland D. K. Muyembe School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, People’ s Republic of China