Effects of high water supply on growth, water use, and nutrient allocation in willow and poplar grown in a 1-year pot trial

This study was carried out to test ex situ growth and soil nutrient removal efficiency of 1-year-old potted willow and poplar plants. Plants were grown under two different water regimes: low irrigation— around soil field capacity (W)—and high irrigation— five times higher than field capacity (W5). Results showed that plant productivity and water use efficiency were greater when trees were grown in the appropriate level of soil water content rather than at excessive moisture levels. Nutrient leaching was also affected by the high irrigation treatment. However, the poplar and willow clones used in this experiment showed different nutrient allocation patterns in the plant–soil–water system. The poplar clone accumulated the highest quantities of N and P in the soil. Willow accumulated N and P mainly in the biomass due to better root development under both treatments. This indicates the better performance of the willow clone in removing N and P from contaminated aquaculture wastewaters during the first growing season