The Salt Transport Between Water In The Ditch And Adjacent Soil Under Storage Condition

Soil salinization is one of the four environment problems that the dry farming faced to in the world. The traditional saline soil treatment take the method of "wash the salt by Plenty of water,underground drainage". Take away the salt infiltrat from surface soil by underground drainage. The saline treatment method based by row has many problems when the saline soil get improved. Such as, so big of irrigation and drainage engineering quantity, input costs running costs maintenance costs are very high, and the construction is very tedious, the system need sustained external manual intervention, wash the salt and drainage cost too much water, the regional groundwater level decreased, the climate tends to drought; The saline water drained away pollute the downstream, and so on.Based on the concept of saline water is also water resources, "change drainage to impoundment" treatment model was proposed, and was applied very well in LuBoTan ten years practice. The paper showed the change trend of salt according the long—term field observation experiment, analysed the salt diffusion between water and adjacent soil and designed laboratory simulation experiment. Demonstrated the direction and intensity of salt diffusion, give the strongly support for the "change drainage to impoundment" treatment model, the main achievements were:1,the observation datas of long-term field observation experiment showed that the soil salinity was declined from 0.465 percent to 0.210 percent, The pH value were decreased from 9.54 to 8.35, the ions such as Cl-,SO42-,HCO3- were lower than initial value, the soil organic matter content was increased to 1.18 percent from 0.463 percent, the soil quality got improved, the serious saline-alkali land became high yielding fertile farmland. It illustrateed "change drainage to impoundment" treatment model was feasible by the practical effect.2,the results of water—the adjacent soil salt transport experiment in laboratory showed that the soil salt was reduced, the total salt of water was increased, the salt diffusion from soil to water, the more nearly to the water the soil salinity changed more obviously. 3 the results of improved water—the adjacent soil salt transport experiment in laboratory showed that the soil closer to water the soil salinity changed faster. The main reason was soil has a certain adsorption, it can impede salt transport in soil.We consider that the impact to soil salinity of ditch water is limited, there was a maximum range in the horizontal direction.4,the results of taking the salt from upper soil to subsoil by cyclic changing water level experiment in laboratory showed that according changing the salt concentration and water level can make the salt in upper soil reduce and the salt in subsoil increase. Changed the soil salinity distribution in the vertical spatial, took the salt from upper soil to subsoil.