Movement and Numerical Simulation of Soil Water and Salt of Greenhouse Under Different Irrigation Amount

In order to explore the most suitable irrigation amount that could prevent the secondary salinization of greenhouse soil,an indoor soil column test was conducted to study the variation characteristics of soil profile moisture and soil electrical conductivity under different irrigation amount.A corresponding model was also used to forecast the change trends of soil water and salt.The simulated data had been verified using the measured data.The experiment results showed that variation of soil water content under different irrigation amount mainly concentrated in the layer of 0-30cm.Water content in soil profile decreased with increasing irrigation amount.The desalt zone of different treatments were formed in the layer of 0-30cm,and salt accumulation zone were formed in the layer of 30-50cm.The water and salt prediction showed that HYDRUS-1Dmodel had a high precision for the simulation of water and salt movement.According to the distribution of water and salt under different treatments in the soil profile,600ml was considered as the most suitable irrigation amount under the experimental conditions.