Effects Of Exogenous Selenium Fertilizer On Oat Yield And Soil Fertility

This study was divided into two parts:1.The selenium fertilizer spraying experiment on oat varieties was carried out,and the two-factor split zone design was adopted.The application mode of selenium fertilizer was secondary area.Spray application(FA),no fertilization(CK),2 levels,10 treatments,3 replications,plot area:666.7m2 random arrangement.The amount of selenium fertilizer sprayed was 800 mg/100 mL.2.The experiment of oat variety topdressing+selenium fertilizer spraying adopted the two-factor split zone design,and the main area was set as variety:jinyan no.21 and jinyan no.19;3.The application mode of selenium fertilizer was secondary area.Soil application(SA),spraying(FA),soil application+spraying(SA+FA),no fertilization(CK),4 levels,8 treatments,3 replications,plot area:666.7m2 random arrangement.The amount of selenium fertilizer applied to soil was 10.8g·hm-2,and the amount of selenium fertilizer sprayed was 800 mg/100 mL.(1)to study the effect of exogenous selenium fertilizer on the agronomic characters and yield of oat.(2)to study the effect of exogenous selenium fertilizer on selenium content in oat seeds of various varieties;(3)to study the effect of exogenous selenium fertilizer on the content of heavy metals in oat rhizosphere soil of different varieties;(4)to study the effect of exogenous selenium fertilizer on the rhizosphere soil fertility of oat oat cultivars;The measured indexes included agronomic characters and physiological indexes of oat(plant height,main stem node and each node length,length and width of main stem functional leaves,number of root per plant,age of main stem and leaf,stem diameter,number of spikelet).Economic characters of oat of each variety(total number of ears,total number of plants,grain weight per ear,thousand grain weight,actual yield,);Soil nutrients(alkali-hydrolyzed nitrogen,available phosphorus,available potassium,organic matter,total nitrogen,total phosphorus),heavy metal content and soil enzyme(alkaline phosphatase,sucrase,urease)activities in the underground part of oat of each variety.The specific research results are as follows:1.Jinyan no.16 was optimal,with a yield of 3737 kg·hm-2 and a 1000-grain weight of 28.23g.Compared with CK,the yield increased by about 55%after spraying selenium fertilizer.The total selenium content in oat grains was increased by 175%to 25%after spraying selenium fertilizer.The total selenium content in grain(FA)of jinyan no.16 was up to 134.96 g/kg,and the total selenium content in oat grain was increased by 175%(the highest)after spraying selenium fertilizer.2.Compared with CK,the yield of SA+FA increased by about 82%.This indicated that selenium fertilizer spraying had a significant effect on the economic properties of oat and could increase the yield of oat.But because of the difference of oat varieties,the varieties showed the difference under the same amount of selenium fertilizer spraying.Soil application plus selenium fertilizer spraying(SA+FA)could maximize oat yield.3.The results of this experiment show that the selenium content in the local soil is relatively high;Selenium accumulation in oat root system was the highest at heading stage,followed by leaf,stem and ear.From heading stage to flowering stage to maturity stage,the accumulation of selenium in root system decreased significantly as the growth center moved from ear to ear,which was the lowest in all organs.Selenium accumulation in leaf gradually increased to the highest level in all organs.Secondly,the acceumulation of selenium in stem increased,but the change of selenium accumulation in stem was not significant.4.According to GB 15618-2008 "soil environmental quality standard.soil pollutant content standard,heavy metal content does not meet the standard,no pollution.Chromium(Cr)element is slightly polluted and has potential harm.According to table 4-4,the relationship between selenium and other heavy metal elements in soil after selenium fertilizer spraying is shown.Except for Pb,fertilizer spraying can affect the changes of other heavy metal elements in soil.When spraying selenium fertilizer,the amount of selenium fertilizer should be controlled.5.Under this experimental condition,through different spraying selenium fertilizer processing,according to the different development stages of the different varieties of oats in rhizosphere soil enzyme activity in the conclusion:the changes of both foliar spraying selenium fertilizer and soil selenium fertilizer can improve the activity of soil urease,foliar spraying selenium fertilizer treatment,soil urease activity in the value compared to other treatment.Selenium fertilizer significantly inhibited alkaline phosphatase activity in rhizosphere soil(ji zhangyan no.4 was the opposite).The activity of sucrase in rhizosphere soil with soil application and selenium spraying was relatively high.6.The results showed that soil application,:soil application+spraying and spraying treatment significantly inhibited the alkali-hydrolyzed nitrogen,available phosphorus,available potassium and total phosphorus in the oat rhizosphere soil of each variety.Soil application,soil application+spraying treatment significantly inhibited organic matter and total nitrogen,while spraying treatment significantly promoted organic matter and total nitrogen in oat rhizosphere soil of all varieties.