Effects Of Organic-inorganic Superabsorbent Composite On Water Absorbency And Physicochemical Properties Of Soil

China is one of the most water sources scarced countries in the world.In china, the area of arid and semi-arid regions is 455×10~4km~2,takes up 47%of the total area of China.Seasonal drought occurred in some regions even the precipitation is large,and the regional and seasonal distribution of precipitation is maldistribution. With the dramatically increasing of water scarce,water resource has become one of the restricting factors in sustainable development of agriculture.Super Absorbent Polymer(SAP) is a kind of new functional macromolecule material,which can suck up water outnumbering oneself thousands to one,has well absorbency and water retention capability.The result showed that after the use of SAP,it can fully absorb irrigation water and natural rainfall,prevents water leakage and loss,and increases efficiency of water utilization.At the same time the SAP has some promote effect to increase the content of the soil aggregate,to improve pore structure in soil,to prevent soil erosion and to increase the effective utilizing rate of chemical fertilizers and pesticides.Therefore,SAP has a wide application prospect in west droughty area.However,some SAP products have some problems on the market at present,such as water absorption is unstable,price on the high side and saline-alkali sensitive.It's the severe obstruction of its application on agriculture,forestry and ecological environment construction.Thus, the introduction of low cost inorganic raw material into Inorganic-organic Superabsorbent Composite synthesis has become a perfect method.In recent years,poly(acrylic acid)/attapulgite superabsorbent composite is manufactured successfully by center for coo-materials and eco-chemistry of Lanzhou institute of chemical physics of chinese academy of sciences.This thesis is aimed at investigating the Inorganic-organic Superabsorbent Composite's performance of water holding in the loessial soil,garden soil and sandy soil under drought condition,and studying the effect of three soils physical and chemical properties using the Inorganic-organic Superabsorbent Composite compared with the most representative Polyacrylic Acid Superabsorbent Composite on the market. According to all of the results,we can concluded that:(1) The Inorganic-organic Superabsorbent Composite is better water retention and long residual action than the Polyacrylic Acid Superabsorbent Composite in the practical application.In this experiment,all using are saline alkali soils which pH value are higher.As a result,there is a high demand on the salt tolerance of the SAP.By continuous 9 times and even 18 times repeatedly used,it concludes that Inorganic-organic Superabsorbent Composite exhibits high salt tolerance and well water retention and long residual action in three soils.But the Polyacrylic Acid Superabsorbent Composite's water retention falls markedly.Soil properties has remarkable effect on the SAP application.It shows that the Inorganic-organic Superabsorbent Composite is more suitable for applying in saline alkali soils which located in north-west arid regions in China.(2) Different types SAP have different effect tendencys and influence degrees with different soils.The Inorganic-organic Superabsorbent Composite could improve soil.Among them,the Inorganic-organic Superabsorbent Composite is more obvious modifying about soil electrical conductivity and soil bulk density in the loessial soil,has well effects on soil electrical conductivity and the pH value in the garden soil,and the granular structure and soil electrical conductivity are better improvement.In the demonstration application must choose suitable soil,a kind of SAP unsuitable for all soil.(3) Dosage of SAP is not the more,the better.Integrated these effects of water retention and soil physical and chemical properties,the goal is pursue the Inorganic-organic Superabsorbent Composite has reasonable performance price ratio in the real application.Suggestion the optimum quantity of the Inorganic-organic Superabsorbent Composite is 0.25%in theloessial soil and garden soil,and 0.50%in the sandy soil.It will lay a solid theoretical foundation for application of the Inorganic-organic Superabsorbent Composite in crops.(4) It is endowed with new special attributes for adding 30%attapulgite in the the Inorganic-organic Superabsorbent Composite.Not only it has excellent change saline alkali soil,but also greatly reduces production costs.