Effects Of Reduced Nitrogen Fertilizer Inoculation With Rhizobia On The Growth And Yield Of Black Soybean

With the purpose of exploring the important of reducing nitrogen application and inoculating Rhizobia on the actual production of black soybean,to explicit the effect wirh differnt amount of nitrogen fertilizer on the premise of inoculating rhizobia on the growth with the yeild of blck soybean,in order to reduce the production cost and protect the Phaeozem land.The experiment was conducted in Heshan farm experimental base of 93 branch of Heilongjiang Beidahuang group from 2019 to 2020.Qingrenwu No.1,a black soybean variety planted by Nenjiang farm,was used as the test variety.The random block design was repeated for three times.Three nitrogen application rates were set:local nitrogen application rate(100%),local nitrogen application rate(50%)and no nitrogen application rate(0);There were two treatments of inoculating rhizobia and non inoculating rhizobia in each nitrogen application rate.The effects of inoculating Rhizobia on the growth and yield of black soybean were studied.The experimental results show that:1.Compared with normal fertilization,reducing nitrogen fertilizer can significantly reduce the height of the plant and the area of leaf.Inoculating rhizobia can help the growth of black soybean.This phenomenon was very obvious at black soybean pod setting stage.2.Compared with normal fertilization,no nitrogen fertilizer can significantly reduce the nodule quantity and fresh weight of the root nodules of black soybean plants.The treatment of reducing the application of 50%nitrogen fertilizer is shown to promote the nodule.Rhizobia seed dressing can significantly improve the number of nodules in different growth stages of black soybean.Among them,T3 treatment was obvious.3.Compared with normal fertilization,reducing nitrogen fertilizer can significantly reduce the chlorophyll content,net photosynthetic rate,transpiration rate and intercellular CO₂concentration of soybean leaves.Inoculating rhizobia can promote the chlorophyll content and the related indexes of photosynthetic characteristics of black soybean plants.4.Compared with normal fertilization,reducing nitrogen fertilizer can significantly reduce the accumulation of dry matter in black soybean plants,and inoculate rhizobia can promote the dry matter accumulation of black soybean.The effect of this promotion was obvious in the treatment of rhizobia inoculated with 50%nitrogen fertilizer.5.Compared with normal fertilization,the accumulation of nitrogen,phosphorus and potassium in black soybean plants was significantly reduced by reducing nitrogen application,and the accumulation of nitrogen and phosphorus in black soybean plants was promoted by inoculating rhizobia.The effect of this promotion was obvious in the treatment of rhizobia inoculated with 50%nitrogen fertilizer.6.Compared with normal fertilization,the yield of black soybean was significantly reduced by reducing nitrogen application,and the yield of black soybean was improved after inoculating rhizobia.The effect of this promotion was significant in reducing the application of 50%nitrogen fertilizer to inoculate rhizobia,with an increase of 4.2%in 2019 and 7.9%in 2020.In conclusion,reduced application of nitrogen fertilizer to inoculate rhizobia can significantly improve the growth,leaf chlorophyll content,net photosynthesis and photosynthetic rate of black soybean,promote the accumulation of dry matter and nutrients,promote the nitrogen accumulation of pod bark and seed,increase the pod number and seed number per plant,and finally improve the yield and economic benefit of black soybean.In this experiment,the treatment effect of 50%reduced nitrogen fertilizer and inoculation of rhizobia is the best,and the economic benefit is considerable,and it is suitable for practical production and application.