Study On The Influencing Factors Of Soil Selenium Content And The Law Of Rice Selenium Abundance In Southern Jiangxi

Se is an essential trace element for human body and animals.In China,there are a large number of people with selenium deficiency,and the potential harm of selenium deficiency is great.The Se-rich soil in southern Jiangxi has a wide distribution area,and the natural Se-rich rice has a high Se-rich rate,and the natural Se-rich rice has a high medical and economic value,so there is a good prospect of developing Se-rich rice characteristic agricultural products in southern Jiangxi.To support the reasonable exploitation and se-enriched jiangxi selenium-rich soil characteristic agriculture development,this paper collected soil and rice seeds and root soil samples and vertical profile of the sample for laboratory test and analysis,combining with the existing 1:25 and 1:50000 regional geochemical survey data,conduct gannan region soil selenium content influence factors and law of se-enriched rice research,The main conclusions are as follows:(1)Se-rich land resources are abundant in southern Jiangxi.The surface soil selenium content showed a trend of "high in the west and low in the east,high in the south and low in the north".The vertical soil selenium content showed a trend of "increasing first and then decreasing" with the increase of depth.(2)The selenium content in soil is affected by geological background,soil genesis,land use,soil texture,soil mineral composition and soil physical and chemical properties.Among them,the geological background is the main controlling factor affecting the selenium content in the surface soil,and the soil formed by the geological units of black rock series is more enriched in selenium.(3)There were differences in soil selenium absorption and enrichment among different crops in southern Jiangxi.Se content and Se enrichment ability of seed crops were higher than those of melon and fruit crops.The selenium enrichment rate of crops from large to small is:corn > pepper > eggplant > rice > bean > lotus seed > bayberry > oil tea > peanut > bitter melon > passion fruit > sweet potato > navel orange.Among them,maize,pepper,eggplant and rice have the higher selenium enrichment rate and ability,which have the potential to develop selenium-rich agricultural products.(4)The rice in southern Jiangxi has high Se enrichment rate and strong Se enrichment ability,so we should focus on developing Se enriched rice.The absorption of Se in rice seeds is affected by many factors,such as the total Se content and its form,pH value and the principal component of the root soil.Soil total selenium is the base and source of selenium in rice seeds.The selenium in the root soil was absorbed by the roots and accumulated,then dispersed by the upward migration of straw,and then had a tendency to accumulate at the seed.(5)Se in the soil of southern Jiangxi was mainly in the form of residual,strongly organic and humic acid binding,accounting for 92% of the total Se,while Se in water-soluble and carbonate-bound forms were more easily absorbed and utilized by rice.(6)The linear regression equation of Se in rice seed and the contents of total Se,MgO and S in root soil was established.The established fitting model was statistically significant according to the level of α=0.05.By error evaluation,the prediction accuracy of the model is high.