The Study And Simulation To Freezing Irrigation With Saline Water On The Old Jiyun River Course Saline Soils

Soil salinization is produced in a specific climate, hydrology, geology under the combined action of salt accumulation in soil phenomenon, is China’s major land degradation types. Tianjin Sino-Singapore eco city is one of the most difficult Tianjin green area, with high soil salinity, water resource shortage etc.. Due to the demand management of saline alkali soil improvement measures of common freshwater resources are relatively large, this paper studies the method of a kind of water saving improvement of saline and alkaline land:Freezing Irrigation With Saline Water. Through the soil column experiment on freezing irrigation with saline water improved saline soil were studied, and explores the effects of plastic film mulching irrigation water salinity and irrigation improvement effects on freezing irrigation with saline water technology; By using HYDRUS-1D on condition of small irrigation quota under the water pressure of water salt salt cloth surface soil were modeled and the model, and the the soil water and salt frozen saline water irrigation condition after treatment were compared, results found:(1) Improved irrigation with saline water ice has better effect on 0-50cm soil, under the experimental conditions, the desalination rate reached 29%, of which 30-40cm of soil desalting effect is the best;(2) 0-50cm soil desalting effect decreased with the increase of salinity of irrigation water mineralization degree, in 8g/L, the desalting rate is 21.9%; when the salinity was 32g/L, soil salt deposit, salt accumulation rate was 51.6%; salinity of irrigation water there is a critical value between 16g/L-24g/L, when the salinity of irrigation water is higher than that of the critical value, irrigation with saline water ice will make the 0-50cm soil salt deposit, only the salinity of irrigation water is below the critical value, frozen saline water irrigation can effectively improve the surface of saline alkali soil;(3) 0-50cm soil desalting film can prolong the frozen saline water irrigation, prolong the average for more than a week, and effectively reduce the degree of soil salt. Plastic film mulching on soil salt of 0-20cm recurrent inhibitory effect is more significant, the salt in 20-50cm soil layer had no obvious inhibition effects.(4) Hydrus-1D can be used to simulate the reflection and vertical direction of soil water and salt changes, and the bigger irrigation quota, the influence of salt content in deep soil is significant; and compared the salt and saline ice water pressure effect of irrigation on soil salinity, irrigation with saline water ice in the soil layer of 20-50cm was found on the salt effect water pressure is better than that of salt, but the salt effect of persistent 0-20cm and 0-30cm salt on the salt to be inferior to fresh water pressure.