淹水稻田抽穗开花期氮磷变化及最佳排水时机

通过蒸渗仪试验,研究了淹水稻田在水稻抽穗开花期不同渗漏水平下稻田水氮磷的变化特性,建立了基于减污的多目标模型.结果表明:在水稻抽穗开花期淹水条件下,整个淹水期间地表水和地下水TP和NH3-N质量浓度均呈先降后增的趋势,NO3--N质量浓度则相反;渗漏强度的大小对抽穗开花期稻田地表水和地下水的TP,NH3-N以及NO3--N的质量浓度影响不显著;在淹水条件下,水稻抽穗开花期在低渗漏水平时,宜在控水第4天进行地表排水.

Changes of nitrogen and phosphorus at sprouting and blooming stage and optimal drainage time in flooded paddy field

The concentration changes of nitrogen and phosphorus under different seepage conditions at the sprouting and blooming stage in a flooded paddy field were studied through lysimeter experiments.A multi-objective model was established for pollution abatement.The results show that at the sprouting and blooming stage,the concentrations of TP and NH3-N in surface water and groundwater in the paddy field initially decreased and then increased during the flooded period,and the concentration of NO-3-N changed in reverse;and the influence of the seepage rate on the concentrations of TP,NH3-N,and NO-3-N was not significant.The simulation results of the multi-objective model show that surface drainage should be carried out on the fourth day after water control at a low seepage level during the sprouting and blooming stage in the flooded paddy field.