A Study On Comprehensive Improvement Technologies About The Saline-alkali Soil In Pudong's Mudflats

With the development of industrialization and urbanization,the quality of China's available arable land is gradually declining and the originally limited land resource is becoming more and more scarce.In order to guarantee our national food security and realize the goal of national food's basic self-sufficiency,the importance of holding fast to the red line of 1.8 billion mu's arable land becomes rather obvious.In the meantime,the development and utilization of saline-alkali soil are endowed with positive significances,because it can not only enlarge the area of arable land,constantly increase per unit output and thus effectively alleviate food crisis,but also can improve ecological environment and enhance people's living standard.With the research method of combining theory and practice,this thesis focuses on the researches of the comprehensive improvement technologies of hydraulic engineering measures and biological measures about soil utilization of saline-alkali soil in Pudong's mudflats in order to reduce the soil salinity and pH value and increase soil plough horizon's nutrient and achieve the aim of planting rice in good time and enhance rice yields year by year.After four years' improvement of mudflats,the average value of soil salt content is 1.7g/kg,which is 2.27g/kg lower than the basic soil salt content of Dongtan,namely 3.97g/kg in 2008.The average pH value of soil is 8.10,which is 0.46 lower than the basic soil pH value of 8.56 in 2008.The soil's average organic matter content is 18.70g/kg,which is 6.80g/kg lower than the whole area's average organic matter content.The soil's alkaline hydrolysis nitrogen content is 73.8mg/kg on average,which is 61.2mg/kg lower than the region's average value of 135mg/ kg.The average effective phosphorus content is 21.0mg/kg,which is 11mg/kg lower than the region's average value of 32mg/kg.The average content of quick acting potassium is 363.3mg/kg,which is far higher than the district's average level.Besides,the yield per unit of rice's typical fields reaches at 10257.46kg/hm2,approaching the hybrid rice's output level of the whole area's rice fields with high yield.In order to make Dongtan a demonstration industrial highland of modern agriculture,achieve the standardization of farmland production and normalization of farmland facilities and realize the high-yield,high-quality and high-efficiency production goal,this thesis is aimed at further cultivating a safe agro-ecosystem industry chain to obviously improve the farmland's soil property in Dongtan,effectively enhance soil fertility,make farmlands' engineering facilities more and more perfect and farmland ecosystem safer and safer,achieve the standard of grain fields with high and stable yields,promote the sustainable development of Dongtan's agriculture and make a contribution to urban development and food security.