Research On Technology Of Subsurface Drainage Improve Sodic Soil

Aiming at the problem of heavy saline soil, weak percolation ratio in the west of Jilin province, the status and developments of subsurface pipe drainage and melioration of saline alkali soil at home and abroad, subsurface pipe was introduced to improvement of soda-typed saline-alkaline soil in western Jilin province. In this study, we studied effect of different arrange mode of subsurface pipe, different depth of subsurface pipe, spacing and different deep loosening cultivation on the physical and chemical properties, rice growth status and yield of soda-typed alkaline soil, at the same time, we also investigated effect of subsurface pipe on water quantity and water quality, groundwater level and soil Hu. The results showed as follow:(1)There was a significant improving effect when buried depth was0.8m, it could decrease percolation ratio and soil compaction, improve soil structure. At the same time, base saturation and exchangeable sodium percentage reduced. Compared with CK, pH decreased1.33, conductivity of soil decreased0.37ms/cm, total salt content of soil decreased0.164%.Compared with CK, content of organic matter increased2.78g/kg, available nitrogen, available phosphorus, available potassium and cation exchange capacity respectively increased6.98mg/kg,2.43mg/kg,13.04mg/kg and7.23cmol/kg; The treatment also promoted the growth of rice and increased rice yield, spike number, ear length,100-seed weight, grain number, seed-producing percentage.(2)5m of spacing was abled to have best effect, it could decrease percolation ratio and soil compaction, improve soil structure. At the same time, base saturation and exchangeable sodium percentage reduced. Compared with CK, total salt content of soil decreased0.156%. Compared with CK, content of organic matter increased3.58g/kg, available nitrogen, available phosphorus, available potassium and cation exchange capacity respectively increased6.02mg/kg、3.06mg/kg、10.17mg/kg and7.31cmol/kg; The treatment also promoted the growth of rice and increased rice yield, spike number, ear length, hunder-seed weight, grain number, seed-producing percentage.(3) The optimal effect of deep loosening cultivation was0.6m. Compared with CK, it could decrease percolation ratio and soil compaction, improve soil structure, At the same time, decreased conductivity of soil, total salt content of soil, base saturation and exchangeable sodium percentage reduced.content of organic matter, available nutrient and cation exchange capacity; The treatment also promoted the growth of rice and increased rice yield, spike number, ear length,100-seed weight, grain number, seed-producing percentage. (4)Subsurface pipe could affect quality groundwater and subsurface pipe drainage. pH, conductivity, content of Na+、CO32-、HCO3-、Cl-from pipe drainage.(5)Subsurface pipe decreased oxidizability of Hu, but enhanced aromaticity, and made molecular structure complex.