Effects Of Selenium And Cobalt Combined Application On The Yield, Quality And Soil Fertility Of Two Cultivars Of Soybean

A. pot experiment with high protein soybean cultivar G and conventional soybean cultivar P was conducted to study the effects of selenium and cobalt combined application on the yield, quality and soil fertility and the difference of two cultivars of soybean.The results were showed as follows:1.The combined application of selenium and cobalt can improve the mineral nutrient of soybean plants and improve the content of nitrogen,phosphorus and potassium in plant. Except pod, The cross application of selenium and cobalt with low concentration can promote the nitrogen content of two kinds of soybean plants’each organ obviously.Except root,the nitrogen content of G’s each organ are higher than P’s.Selenium with middle and low concentration can promote the phosphorus content of two kinds of soybean plants’each organ obviously, selenium and cobalt can restrain the accumulation of phosphorus. The phosphorus content of G’s in root, stem and pod are lower than P’s. The phosphorus content of G’s in leaf and grain are higher than P’s. But compared with the control group,the fertilization of selenium and cobalt have more positive effect on improving the phosphorus content of P. The potassium content of G’s in root and stem are lower than P’s.The cross application of selenium and cobalt with low concentration can promote the potassium content of two kinds of soybean plants’each organ obviously.The potassium content of G’s in pod and grain are higher than P’s. The potassium content of G’s in leaf is consistent with P’s. The nitrogen,phosphorus and potassium’s distribution in mature stage is that grain> leaf> root> stem> pod; Grain> leaf> stem> root> pod; Grain> leaf> stem> pod> root.2.The chlorophyll content increased at initial stage and then the content declined with the process of two kinds of soybean growth period, the peak appeared at podding stage.The chlorophyll content of G’s is higher than P’s in generally, especially at seeding stage. The fertilization of selenium and cobalt have more positive effect on chlorophyll content’ improvement of P. Selenium and cobalt with middle concentration can make more positive effect on G. Selenium and cobalt with low concentration can make more positive effect on P. 3.Soybean can accumulate selenium of soil in the whole growth period and mainly in the late growth stage. The content of Se in grains was higher than other organs obviously.In Se and Co combined applications, Content of selenium in the plant was increase effectively when the application of high concentration of Se and low concentration of Co. Excess cobalt inhibited the accumulation of selenium in plant. Treatment of S3C2promoted the selenium content of two type of soybean grain most effectively and the content of selenium was below the maximum safe amount of livestock and poultry. For further processing perspective, it was the best combination. The selenium content of G’s in grain and pod are higher than P’s,but the selenium content of G’s in other reproductive organ are lower than P’s.The accumulation dynamic of Soybean to Co similar to selenium during the whole growth period. The content of cobalt in grains was in the first place and was higher than other organs obviously. The promoting effect of Se and Co combined application on content of cobalt in different organ was different. The content of Co in the two kinds of soybean grain were largest in the application of midium concentration of Se and Co.Furthermore,the Co content of G’s in grain is higher than P’s, the fertilization of selenium and cobalt can increase its content more easily.4.With two kinds of soybean continuous growth, the content of available selenium and available cobalt decreased. Pod stage is a fastigium that two type of soybean pod absorbed selenium and cobalt. Soil selenium contents increased with increasing selenium content and soil cobalt contents increased with increasing cobalt content in application of selenium or cobalt alone. In Se and Co combined applications, almost all treatments have positive effect on the soil content of available selenium and cobalt.The application of high concentration of Se and mid and low concentrations of Co have positive effect on the available selenium content of G and P. The application of low concentration of Se and high concentrations of Co have positive effect on the available Co content of G and P. Soil available content of Se of G is lower than P in the growth of soybean during the whole growth period. Soil available content of cobalt of two are different under the different periods and treatments, no unified rules.5.1n the soybean growth period, the activity of soil phosphatase, saccharase and catalase are increased at initial stage, The peak appeared at podding stage and then the activity declined. Selenium and cobalt with low concentration can promote the soil phosphatase activity of the two kinds of soybean obviously. Selenium and cobalt with middle concentration can promote the saccharase activity of the two kinds of soybean obviously. The activity of the other two kinds of enzyme are different in different period and treatment. The soil phosphatase and saccharase activity of G are higher than P’s generally. The soil urease activity of G is higher than P’s in seedling and flowering stage. The soil urease activity of G is lower than P’s in pod and mature stage. The catalase activity of G is higher than P’s markedly in seedling stage,but catalase activity of them are consistent in maturity stage.It proves that fertilization of selenium and cobalt can improve the activity of P’s soil phosphatase and urease more obviously.6. Combined application of selenium and cobalt with middle or low concentration can make more positive effect on the production of soybean and100-seed weight. The production of G and P reaches maximum value in treatment S1C1and S1C2which increased33.36%and32.7%than the respective control. The production of P is higher than G’, but the100-seed weight of P is significantly lower than G’.7.The crude protein content of the two kinds of soybean seeds is restrained in high concentration of cobalt and the rest can promot the crude protein content of the two kinds of soybean seeds. G and P reaches maximum value in treatment S3C0and S1C2which increased12.9%and37.9%than the control respectively. The treatment of S1C1’promotion effect on G is only less than S3C0’, which increased10.8%than the control. The grain’ crude protein content of G is higher than P’.It can explain that the fertilization of selenium and cobalt can make more positive effect on P’ crude protein content from the promotion rate of the two kinds. Only applying selenium or cobalt,the crude protein production of G is higher than P’.The crude protein production of P is higher than G’on the condition of the fertilization of selenium and cobalt. G and P reaches maximum value in treatment S1C1and S1C2,the content of crude protein Increased47.8%and45.5%than the control respectively. The differences reach significant level.8. Consider the production and quality of the two kinds of soybean,the treatment of S1C1and S1C2are the best combination with G and P respectively.