Effects Of Soil Application Of Selenium Mineral Powder On Physiological And Biochemical Indexes,Selenium Content And Nutrient Contents Of Radish

In order to understand the bioavailability of selenium in selenium ore powders,providing a basis for the agricultural use of selenite powder,in this experiment,treatments of0,3,5,10,20,25 and 50 g/kg of selenium mineral powder and 1 and 5 mg/kg of sodium selenite were applied to the soil,a potted trial of radish was conducted over a period of more than four months.The germination rate of radish seeds,selenium content of radish seedlings,biomass,vitamin C(Vc),soluble sugar,malondialdehyde(MDA),photosynthetic pigment,water-soluble nutrient content,catalase(CAT)activity and Selenium content,biomass and nutrient content of radish at maturity,as well as selenium content,selenium morphology and basic physicochemical properties of potted soil.The results showed that the appropriate amount of selenium mineral powder applied to the soil was beneficial to seed germination,and the germination rate and germination potential were the highest in the treatment of 3 g/kg selenium mineral powder;The concentration of soil applied selenium mineral powder was highly significantly and positively correlated with the selenium content of radish seedlings,but the biomass of all radish seedlings was significantly lower than that of the control;The application of 10 g/kg increased70% of the Vc and 50% of the soluble sugar content of radish seedlings compared with the control,However,the application rate of 50g/kg significantly reduced the Vc and soluble sugar content of the leaves.Excluding the control,there was a significant positive correlation between the catalase activity of radish seedlings and the soil selenium ore powder applications.The MDA content of radish seedlings was significantly reduced by the selenium ore powder applications of 10 and 25 g/kg.Appropriate selenium mineral powder applications increased the photosynthetic pigment content of radish seedling leaves with the highest content at 10g/kg,while the highest application of 50 g/kg reduced the photosynthetic pigment content significantly.Except for 25 g/kg,the soil selenium ore powder applications reduced the ratio of chlorophyll a to chlorophyll b significantly.There was a significant linear relationship between the photosynthetic pigment content and the soluble sugar content in the leaves of radish seedlings;Appropriate application of selenium mineral powder in soil can significantly increase the content of water-soluble total nitrogen,nitrate nitrogen,ammonia nitrogen and organic nitrogen in leaves,Soil application of selenium mineral powder showed an inhibitory effect on the content of water-soluble total phosphorus in leaves at the seedling stage of radish,but the content and proportion of water-soluble organic phosphorus in the treatment of 20g/kg and 50g/kg of selenium mineral powder were significantly higher than those of the control.Soil application of selenium mineral powder had no significant effect on the biomass of radish;The concentration of selenium mineral powder in soil was positively correlated with the selenium content in radish roots and leaves.Under the same selenium concentration,the selenium content in leaves was higher than that in roots,The selenium utilization rate in the treatment group of selenium mineral powder application was greater at low concentration than at high concentration,Selenium utilization in the group treated with sodium selenite solution was greater at high than low concentrations;Soil application of selenium mineral powder had no significant effect on the Ca content of radish roots,Fe element fluctuates with concentration;Appropriate application of selenium mineral powder in the soil is conducive to the accumulation of N,P,and K elements in the roots and leaves of radish,Among all selenium fertilization treatments,the highest content of N,P and K in radish roots were25g/kg selenium mineral powder treatment and 5mg/kg,5mg/kg sodium selenite treatment,respectively,The highest N,P and K contents of radish leaves among all selenium application treatments were 25g/kg,25g/kg selenium mineral powder treatment and 5mg/kg sodium selenite treatment,in that order,The absorption of nutrients by the roots and leaves of radish is K>N>P,Soil application of selenium mineral powder had a significant effect on N/P,N/K and P/K of radish roots and leaves.Soil application of selenium mineral powder can significantly enhance the total selenium and each form of selenium content in potted soil,At the same selenium application concentration,the content of selenium in soil from high to low was iron-manganese oxide bound selenium,organic and sulfide bound selenium,residual selenium,exchanged and carbonate bound selenium,water-soluble selenium.A highly significant linear correlation was observed between the amount of selenium applied and the whole selenium content and the selenium content of each form in potted soils.There was a highly significant linear relationship between the amount of selenium mineral powder applied to the soil and the total selenium content of the soil and each form of selenium;The contents of soil organic matter,total nitrogen,total phosphorus and available phosphorus in the selenium application group were significantly different from those in the control group,The p H,cation exchange,alkaline nitrogen,ammonium nitrogen,and fast-acting potassium of some selenium treatment soils were significantly different from the control group,There was no significant difference in soil nitrate nitrogen content between the selenium application group and the control group;There were extremely significant linear correlations and quadratic function correlations between soil selenium mineral powder application and soil organic matter,available phosphorus,total nitrogen and total phosphorus content.Soil application of selenium mineral powder can significantly increase the selenium content of radish and has a significant effect on the physiological and biochemical indexes and nutrient content of radish.It shows that selenium in selenium mineral powder can participate in the nutrient metabolism and physiological and biochemical processes of radish,which proves that selenium in selenium mineral powder has bioavailability and can be used as a selenium source for the development of selenium-enriched agricultural products.