基于机械收割要求的稻麦轮作农田暗管排水布局模拟

南方稻麦轮作区现有明沟排水系统影响农业机械作业效率,不利于农业现代化发展;建设暗管排水系统可提高土地利用率和农业生产效率。以江苏省扬州市江都区昭关灌区为例,用农田排水模型-DRAINMOD分析了稻麦轮作农田暗管排水系统布置方案。模拟结果表明:作物收获期机械作业天数受暗管埋深和埋设间距的影响,随着埋深的减小和间距的增大,机械作业天数逐渐减小;在相同保证率和目标水位埋深要求下,水稻收获期的机械作业天数相对小麦收获期更易受降雨的影响。在水稻收获期,当暗管埋深为80~100 cm,满足大型机械90%、95%作业保证率的最大暗管间距分别为:26.0~32.0 m、14.0~21.0 m;满足小型机械90%、95%作业保证率的最大暗管间距分别为:26.5~33.5 m、18.0~23.0 m。研究成果可为类似地区基于机械收割要求的农田暗管排水系统设计提供理论参考。

The Simulation of Drainage Layout in Rice-wheat Rotation Croplands Based on Mechanical Harvesting Requirements

Existing open ditch drainage systems in the rice-wheat rotation area of southern China affect the efficiency of agricultural machinery and restrict quick development of agricultural modernization.Construction of subsurface drainage systems can improve land utilization and agricultural production efficiency.In this paper,the layout of the subsurface drainage systems for rice-wheat rotation croplands in the ZhaoGuan Irrigation Area of Jiangdu District,Yangzhou City,Jiangsu Province is analyzed by using the farmland drainage model-DRAINMOD.The simulation results show that during the crop harvest,the number of machine working days is affected by the buried depth and spacing of subsurface drain pipes.As the drain depth decreases and the spacing increases,the number of working days gradually decreases.With the same rainfall frequency and groundwater depth,the machine working days in rice harvest season are more susceptible to rainfall than that in wheat harvest seasons.In the rice harvest period,based on the requirements of large machine operation requirement,when the drain depth is 80~100 cm,the maximum drain spacing that meets the 90%and 95%probability is respectively 26.0~32.0 and 14.0~21.0 m.Based on the requirements of small machine operation,when the drain depth is at 80~100 cm,the maximum drain spacing satisfying the 90%and 95%probability is 26.5~33.5,18.0~23.0 m,respectively.Findings from this research may provide a technical reference subsurface drainage system design of to meet trafficability requirement of machine harvest in similar rice-wheat rotation areas.