The Effect Of Soil Selenium Content And External Selenium On Soybean Product Quality In Nenjiang City

Selenium,as one of the essential trace elements of human body,has multiple biological effects.The lack of selenium in the human body can cause a variety of diseases,and selenium elements can not be synthesized by the human body,can only be obtained from food.Soybean is the fourth largest crop in China and plays an important role in the diet of Chines e.Therefore,this paper studies the content characteristics of selenium in the soil by sampling the cultivated s oil in14 townships in Nenjiang City.On the other hand,through the external application of selenium,the influence of different selenium application methods on soybean grain quality,yield and soil nutrients is studied,so as to provide a basis for the development of selenium-rich soybean industry in Nenjiang City.The main findings are as follows:（1）The average content of selenium in the soil of Nenjiang City is 0.206 mg·kg^-1,of which the highest selenium content is 0.519 mg·kg^-1,located in Nenjiang Town,and the lowest selenium content is 0.032 mg·kg^-1,located in Changjiang Township.The soil in Nenjiang City is mostly low selenium and selenium-deficient soil,of which enough selenium and selenium-rich soil are distributed sporadically,with a small proportion.There are differences between different types of soil selenium content in Nenjiang City,with higher selenium content in black soi l,followed by dark brown soil and meadow black soil.There is a significant positive correlation between quick-acting potassium and effective phosphorus and soil selenium content.The higher the selenium content of the surface soil of cultivated land in N enjiang City,the higher the selenium content and bio-enrichment coefficient of soybean grain,that is,the selen ium content of soybean grain was positively correlated with the soil selenium content.（2）The effect of leaf surface selenium on soybean root soil enzyme activity was different in different periods,T4（inorganic selenium during the nourity period）treat ment of soil sucrose enzyme and T2（flower inorganic selenium）treatment of soil xenon enzyme activity was lower than CK,the activity of various soil enzymes treated in the rest of the period was generally higher than CK,of which T3（flower organic selenium）period treatment of various soil enzyme activity was higher.The activity of various soil enzymes treated by selenium mixing is higher tha n CK,and the activity of sucrose and enase decreases gradually with the increase of selenium mixing.The effect of selenium T1（inorganic selenium in the seedling period）on soil selenium content was obvious,and there was no significant difference in the rest of the treatment.Selenium mixing can improve soil selenium content to varying degrees,and with the increa se of selenium mixing,soil enzyme activity gradually increases.（3）External selenium application can improve the selenium content of soybea n seeds,wherein the leaf spray selenium fertilizer of soybean seed selenium content range is 0.12 to 0.67 mg·kg^-1,soybean selenium-rich most suitable treatment is T2 treatment（inorganic selenium spray during flowering）.The selenium content of soybean seed selenium treated with selenium mixing ranged from 0.68 to 0.82 mg·kg^-1,and the selenium-rich effect of selenium-rich soybeans treated with selenium mixing was better than that of leaf-based selenium.Among the four different varieties of soybeans,the stronger poly selenium capacity is He bean No.1.（4）The application of selenium from an external source can i mprove the content of many amino acids in soybean grains,especially for increasing the total amount of soybean lysine and amino acids.The total amount of selenium-sprayed soybean seed lysine increased by 3.2%～6.0%and the total amount of amino acids increased by 4.2%～8.4%,of which the total amount of amino acids treated by T3 increased significantly,by 8.4%compared to the control,indicating that organic selenium There was a significant positive effect on the synthesis of amino acids,and selenium mixing processing could improve the content of amino acids in s oybean grains,of which the total amount of amino acids treated with low concentrati ons of selenium-1 was most significant,at 393.6 mg·kg^-1,It is shown that low selenium can promote the synthesis of amino acids in soybeans.（5）The external selenium application has a certain effect on the synthesis of soybean grain protein and fat.In different periods,leaf surface selenium spray can increase the protein and fat content in soybean grains to varying degrees,of which T3（organic selenium sprayed during flowering）treatment can significantly increase the content of soybean protein,but t he effect on soybean fat is not great;Low selenium mixing can improve the protein content of soybean seeds,and higher amount of selenium mixing can increase the content of soybean fat.Among them,selenium mixed seed-2 treatment effect is better,its total protein and fat is higher.The application of selenium from an external source has a certain effect on increas ing the yield of soybeans.Overall,the yield of each treatment increased by 2.4%to 15.0%after the application of selenium from the outside source.