Effect of waterlogging on nutrient uptake and transport of summer maize

Two summer-maize hybrids, Zhengdan958 (ZD958) and Denghai605 (DH605), were selected as experimental materials. A field experiment was performed to explore the effect of waterlogging on nitrogen (N), phosphorus (P) and potassium (K) absorption and transport of summer maize. Results show that N, P and K accumulation amounts are reduced significantly after waterlogging, and the decreases of nutrient accumulation of two cultivars are the most in the treatment of waterlogging at the threeleaf stage for 6 d, with 42.86%, 45.50% and 32.53% in ZD958 and 50.55%, 36.50% and 27.21% in DH605. The nutrient accumulation amounts of each organ and nutrient allocation proportions of grain are decreased significantly after the waterlogging, while the nutrient allocation proportions of stem and leaf are increased. The nutrient contents of stems and leaves are increased, while the nutrient contents of grains are decreased. Furthermore, each organs dry matter accumulation is reduced significantly after the waterlogging, and the decreases of two cultivars are the most at the treatment of the waterlogging at the three-leaf stage for 6 d. At the maturity, the dry matter weights of stem, leaf and grain of ZD958 are decreased by 25.93%, 30.14% and 43.39, and the dry matter weights of leaves and grains of DH605 are decreased by 28.28%, 32.27% and 50.28%. The reductions of stem and leaf nutrient accumulation after the waterlogging are mostly due to the decrease of dry matter accumulation, and the nutrient transfer from stems and leaves to grains is decreased significantly after the waterlogging. It is most sensitive to be waterlogged at the three-leaf stage, followed by the six-leaf stage and the 10 th day after the flower stage, and decreased with the increase of waterlogging duration.