The effect of soil water and salt transport and simulation under drip irrigation
In order to explore the effect of soil water and salt movement under various drip irrigation parameters,a drip irrigation experiment was carried out in the second regiment of the first division in Aksu Prefecture,Xinjiang from June 1st to 27th,2019.Different irrigation quotas(300,450,600 m3·hm-2)and emitter flow rates(2.4,4.5,8.2 L·h-1)were set in the experiment.The tested soils included sandy loam and loam.The effect of emitter flow and irrigation quota on water and salt transport in two soils were analyzed,and the HYDRUS-2D numerical model of soil water and salt in cotton field under mulched drip irrigation was built using the experimental data.The results showed the average soil moisture content in the soil and the rate of surface desalination both with higher irrigation quota and increased emitter flow rate.With the increase of irrigation quota,the vertical desalination depth of sandy loam and loam gradually increased,and the maximum value was 92 cm and 58 cm when the irrigation quota was 600 m3·hm-2.With the increase of emitter flow rate,the vertical desalination depth of loam decreased gradually.When the emitter flow rate was 8.2 L·h-1,the vertical desalination depth of loam was the smallest,and its value was 38 cm.The coefficient of determination between the measured and simulated values of soil moisture content and salinity ranged from 0.89 to 0.93,the Nash-Sutcliffe Efficiency coefficient ranged from 0.82 to 0.89,and the Root Mean Square Error ranged from 0.01 to 0.25.This demonstrates that the HYDRUS-2D model was capable of accurately simulating the movement of soil water and salt in the Aksu region.The results showed that the emitter flow rate of cotton under mulch drip irrigation in the experimental area was 2.4 L·h-1,and an irrigation water volume for cotton emergence was not less than 225 m3·hm-2,which was the appropriate technical parameters for drip irrigation.In the case of limited irrigation amount,try to use larger irrigation quota,use small emitter flow for loam soil,and use large emitter flow for sandy loam soil,which is conducive to desalination of crop roots,and ultimately achieve the purpose of increasing production.
drip irrigationcotton fieldwater and salt transportHYDRUS-2D model
万方数据
维普
