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为了掌握红壤双点源滴灌条件下水分溶质运移规律,为红壤丘陵地区脐橙滴灌灌溉设计和管理提供参考,建立了5个不同红壤容重下滴灌水分和硝态氮运移的数学模型。借助Hydrus-3D模型模拟了不同红壤容重、同一滴头流量和施氮量时土壤水分溶质分布特征和湿润锋推移和交汇过程。模拟结果与试验对比表明:模拟的湿润锋运移交汇过程、湿润体内土壤含水率以及NO3--N含量与实测值之间的偏差均在9.5%以内;模拟值和实测值具有很好的一致性,并显示在湿润锋交汇处土壤含水率和NO3--N含量低于同一深度滴头下方的土壤,另外高容重红壤阻碍湿润锋的推进速度。总体而言,Hydrus-3D可以用于红壤滴灌施肥灌溉条件下湿润体范围以及水分和氮素运移和分布的模拟。
In order to grasp the rule of water and solute transport under the condition of two-point source drip irrigation of red soil, and to provide reference for drip irrigation design and management of navel orange soil in hilly red soil region, mathematical models of drip irrigation water and nitrate nitrogen transport under five different red soil bulk density were established. Hydrus-3D model was used to simulate soil water solute distribution and wetting front transition and convergence process under different red soil bulk density, same dripper flow rate and nitrogen application rate. The simulation results and experimental results show that the deviation between the simulated wetting front and migration process, the soil moisture content in wetted body and the content of NO3 - N are less than 9.5%. The simulated and measured values are in good agreement The soil water content and NO3 - N content in the confluence of wetting front are lower than that of the soil below the same depth dripper. In addition, the redistribution of high capacity and heavy weight hinders the advancing speed of wetting front. Overall, Hydrus-3D can be used to simulate wetting body and the transport and distribution of water and nitrogen under drip irrigation with red soil fertigation.