Analysis And Evaluation Of Soil Nutrient Change Of Cultivated Land In Thirteenth Division

objective:The Corps of the 13^th division for nearly 30 years,the statistical analysis of three time nodes of soil nutrient content in macroelements,clarify the changes of soil nutrient content,put forward reasonable evaluation on soil fertility,and provide scientific basis for rational fertilization and agricultural sustainable development.method:Collect historical data of the soil nutrients in 1984,2007 of 13^th division of this reclamation area,sampled and analyzed the topsoil from 2012 to 2015,calculated by using Delphi technique,using Delphi method and index membership function method to determine the membership function of each evaluation index,calculate the degree of membership the thirteen division,soil nutrient status and evolution trend.Through the correlation and variability analysis of different nutrient indicators,study distribution characteristics of soil nutrients in the 13^th division.Results:1.The survey results show that the level of soil fertility in the 13^th division is medium to high.The content of soil organic matter level belongs to the medium level,which belongs to the four grade level;soil nitrogen content level belongs to the medium level,which belongs to the four grade level;soil available phosphorus content are high,grade three belong to the soil available potassium content is high;the level of grade two belong to.The average soil organic matter is14.5g.kg^-1,level Four,organic matter content changes in the range of 1.0-35.4g.kg^-1;nitrogen content average value is 87mg.kg^-1,belongs to the four level,the range is 13.8-518mg.kg^-1;the content of available phosphorus in average 15.39mg.kg^-1,which belongs to the three level,changes in the range of 3.8-163.2mg.kg^-1;the average content of available K value 197mg.kg^-1,which belongs to the two level,changes in the range of 7.07-604.7mg.kg^-1,2.From 1984 to 2015,the 13^th division of cultivated soil organic matter content decreased by3.4g.kg^-1,the content of available potassium decreased 96mg.kg^-1,nitrogen content increased47mg.kg^-1,available phosphorus content increased 5.09mg.kg-1.the farm tillage soil fertility change of a star:available potassium decreased 334.63mg.kg-1,organic matter content decreased8.4g.kg-1,nitrogen increased 15.56mg.kg-1,P elevated 1.92mg.kg^-1;red two available potassium decreased 11.52mg.kg^-1,organic matter content decreased 3.5g.kg^-1,available nitrogen available phosphorus increased 58.15mg.kg^-1,11.8mg.kg^-1,red star four games available potassium decreased 49.56mg.kg^-1,organic matter content decreased 2.1g.kg^-1,alkali hydrolyzable nitrogen available phosphorus increased 40.85mg.kg^-1,increased 3.24mg.kg^-1;rocket farm available potassium decreased 128.76mg.kg^-1,organic quality of nitrogen content decreased 0.2g.kg^-1,increased 59.21mg.kg^-1,a Effect of phosphorus increased 4.92mg.kg-1;Huang Tian farm potassium content increased by 1.55mg.kg^-1,the content of organic matter decreased 4.8g.kg^-1,nitrogen increased 47.24mg.kg^-1,available phosphorus increased 6.41mg.kg^-1;Willow Springs farm available potassium decreased 22mg.kg-1,organic matter content decreased 6.2g.kg^-1,alkali hydrolyzable nitrogen available phosphorus increased 18.76mg.kg-1,increased 8.27mg.kg^-1;Hongshan farm available potassium decreased 65.54mg.kg^-1 the content of organic matter,nitrogen decreased 1.9g.kg^-1,increased 26.82mg.kg-1,available phosphorus increased9.32mg.kg^-1.3.in the 13^th division,There are 193 strips belong to the First grade cultivated land,the area is23404 mu,accounting for 6.8%of the area survey;825 strips belong to the second grade cultivated land,the area is 109109 mu,accounting for 31.7%of the area survey;615 strips belong to the third grade cultivated land,the area is 181046 mu,accounting for 52.6%of the area survey;225 strips belong to the fourth grade cultivated land,the area is 30633 mu,accounting for 8.9%of the farmland.Conclusion:According to the 13^th division of soil texture,fertility,and soil nutrient status at present,Opinion on macro decision making of balanced fertilization propose:"Controlling nitrogen,reducing phosphorus,stabilizing potassium and supplementing organic matter",that is appropriate to control the amount of nitrogen fertilizer,increase and decrease coordination,suit measures to local conditions;Properly reducing the amount of phosphate fertilizer and decreasing in stability,guided classified;Attach importance to organic supplement,monitor soil organic matter regularly,This is the guiding ideology and principles for rational fertilization of 13^th in recent years.