Aalysis On Change Features Of Cultivated Soil Nutrient In Twelfth Division Of The Corps

In this study,the regiment of the twelfth division for the study area,in the region of second soil collected historical data of cultivated land soil survey(1982)on the basis of investigation,the division of soil nutrients of arable soil completed 2012-2014 years,established the Corps twelfth division of soil nutrient database.This study compares the twelve division of soil nutrient status of cultivated land,and compared with the division in 1982 second soil survey of the historical data,variations of more than 30 years of soil nutrients,and analyzes the causes of soil nutrient changes from the two aspects of natural factors and human factors,the area of cultivated land the quality of the construction and principle of fertilizer.Results show:(1)The organic matter content in the overall level of level above the average performance of the 221 group(22.8 g/kg)>the Threeping farm(20.4 g/kg)>the Toutunhe farm(17.3 g/kg)>the 104 group(17.1 g/kg)>the Xishan farm(16.6 g/kg)>the Wuyi farm(15.5 g/kg)>the 222 group(11.1/kg);32 years,Xishan farms in addition to reducing the content of organic matter,organic matter content increased the rest of the farm.(2)The overall nitrogen content level is above the average,for the performance of the 221 group(128 mg/kg)>the 104 group(103 mg/kg)= the Xishan farm(103 mg/kg)>the Wuyi farm(99 mg/kg)>the Toutunhe farm(97 mg/kg)>the threeping farm(94 mg/kg)>the 222 group(56 mg/kg).In the 32 years,the nitrogen content of all the farms was greatly improved.(3)The content of available phosphorus in the overall level of higher than for the performance of the 221 group(50.4 mg/kg)>the Toutunhe farm(31.6 mg/kg)>the wuyi farm(29.4 mg/kg)>the 222 group(28.3 mg/kg)>the Xishan farm(27.3 mg/kg)>the Threeping farm(26.6 mg/kg)>the 104 group(24 mg/kg).In the 32 years,the available phosphorus content of all farms was greatly improved.(4)The content of available potassium in the overall level is above the average,for the performance of the 222 group(351 mg/kg)>the Wuyi farm(297 mg/kg)>the Threeping farm(231 mg/kg)>the Toutunhe farm(191 mg/kg)>the 104 group(174mg/kg)>the 221 group(160 mg/kg)>the Xishan farm(159 mg/kg).32 years,in addition to the 104 group of quick acting potassium has a slight increase,the rest of the farm has a different degree of available potassium content decreased.The twelfth division should take "increase the organic,control the nitrogen,reduce the phosphorus,and appropriate supplement potassium," the fertilization project.