摘要
采用盆栽试验和Hydrus-1d模型模拟相结合的方法,研究了不同耗水强度下稻田落干脱水过程中土壤含水率与饱和土壤埋深的变化规律,建立了土壤含水率与饱和土壤埋深之间的定量关系。结果表明,在稻田落干脱水过程中,土壤含水率与饱和土壤埋深具有很好的同步变化规律,采用率定后的Hydrus-1d模型能够较好地模拟稻田落干脱水过程中二者的变化。试验和模拟结果均显示,节水灌溉稻田土壤含水率与饱和土壤埋深之间呈明显的二次抛物线关系,即饱和土壤埋深随着稻田落干脱水过程中土壤含水率的降低而增大。基于二者之间的定量关系与传统土壤含水率指标临界值,计算得到了饱和土壤埋深指标临界值,确定了各生育期饱和土壤埋深临界值区间为(0.27 m,0.50 m),由此提出了以饱和土壤埋深为调控指标的水稻节水灌溉技术。该技术采用易于观测的饱和土壤埋深作为控制指标,克服了以土壤含水率、田间无水层天数等控制指标带来的监测成本高、测量精度低等问题,在准确反映田间水分状况的同时,满足了节水灌溉规模化应用的需求。
Putting forward easily-observed and operate rice water-saving irrigation regulation indicators is of great significance to promote the large-scale application of rice water-saving irrigation technology.The method of pot experiment and model scenario simulation(Hydrus-1d)was used to study the variation of soil moisture and the depth of saturated soil during the drying and dehydration of paddy fields under different water intensities.The quantitative relationship between the soil moisture and the depth of saturated soil were established.The results show that the soil moisture and the depth of saturated soil during the paddy field dehydration had a good synchronous change law.The correlation coefficient between the measured soil moisture and the simulated soil moisture was 0.758 by using the Hydrus-1d model,which can better simulate the synchronous change of the two in the process of rice field dehydration.Both the experiment and the simulation results showed that there was a clear quadratic parabolic relationship between the soil moisture and the depth of saturated soil in the water-saving irrigation paddy field,that was,the depth of saturated soil was increased with the decrease of soil moisture in the process of rice field dehydration.In addition,based on the quantitative relationship between the two and the traditional critical value of soil moisture index,the critical value of the depth of saturated soil index was calculated,and the critical value of saturated soil depth in each growth period was ranged from 0.27 m to 0.50 m,forming a water-saving irrigation technology of rice with saturated soil depth as the control index.The technology used easily-observed depth of saturated soil as a control index,which overcame the problems of high monitoring cost and low measurement accuracy brought by using the soil moisture and a fixed number of days in an anhydrous layer as the control index,accurately reflecting the field moisture status,and at the same time,it met the needs of large-scale application of water-saving i
作者
徐俊增
程衡
卫琦
陈鹏
栾雅珺
蔡少杰
XU Junzeng;CHENG Heng;WEI Qi;CHEN Peng;LUAN Yajun;CAI Shaojie(College of Agricultural Science and Engineering,Hohai University,Nanjing 210098,China;State Key Laboratory of Hydrology Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2020年第10期345-352,共8页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家重点研发计划项目(2016YFC0400103)
江苏省高校优秀科技创新团队项目。
