作 者: (郭蓉); (周伟); (高世凯); (王梅); (曹睿哲); (俞双恩);
机构地区: 河海大学南方地区高效灌排与农业水土环境教育部重点实验室,江苏南京210098 河海大学水利水电学院,江苏南京210098
出 处: 《排灌机械工程学报》 2016年第11期990-994,共5页
摘 要: 以农田水位作为水稻旱涝交替胁迫调控指标,在蒸渗测坑进行水稻拔节孕穗期和抽穗开花期的旱涝交替胁迫试验,研究了旱涝交替胁迫下稻田水NH_4^+-N,NO_3^--N的流失规律.结果表明:NH_4^+-N是稻田地表水、地下水氮素的主要形式;旱涝交替胁迫对稻田水NH_4^+-N,NO_3^--N浓度变化影响明显,FDTF较FFTD的稻田水平均NH_4^+-N、平均NO_3^--N浓度都高,FDTF和FFTD均能降低地表水NH_4^+-N,NO_3^--N浓度,FDTF和FFTD涝水胁迫下的地下水平均NH_4^+-N、平均NO_3^--N浓度高于干旱胁迫下;此外,在干旱胁迫后进行涝水胁迫可以显著增加地下水NH_4^+-N,NO_3^--N浓度.因此,应避免旱后复水稻田的排水. NH_4~+- N and NO_3^-- N concentrations in paddy water under alternating drought and flooding stress are studied with lysimeter experiment during jointing-booting and panicle initiation stages by using water level as a regulation index. The experimental results show that NH_4~+- N is the major form of nitrogen in paddy surface and ground water. Alternating drought and flooding stress has significant influence on the change of NH_4~+- N and NO_3^-- N concentrations in paddy water. Compared with FFTD( first flooding and then drought),the mean NH_4~+- N and NO_3^-- N concentrations are significantly greater in FDTF( first drought and then flooding) water. The NH_4~+- N and NO_3^-- N concentrations are decreased in FFTD and FDTF surface water. Moreover,the mean NH_4~+- N and NO_3^-- N concentrations are significantly higher in paddy water under the flooding stress than under drought stress. Inaddition,NH_4~+- N and NO_3^-- N concentrations can be sharply increased in paddy water when a drought stress is followed by a flooding stress. Therefore,drainage should be avoided when the reflooding occurs after drought.