Effects Of Se-Application On The Growth And Se,As And Nutrient Content In Rice Planted In As-Polluted Soil

In order to understand the ecological and environmental effects of Se on As polluted soil,and to provide the reference for the remediation and utilization of the polluted soil,a pot experiment of planting rice Jiafeng(JF),Zhongzheyou(ZY)and Nanjing(NJ)by soil and foliar selenium application was conducted.The biomass,plant height,ear length of harvested rice and the contents of selenium,arsenic,nitrogen,phosphorus,potassium in rice were measured.Soil Se-application reduced the grain yield of three species of rice,but foliar Se-application only decreased the grain yield of ZY.Se-application increased the rice Se contents and the degree was the highest in ZY and lowest in JF.Soil Se-application increased the Se-content in rice roots and husks more than foliar application,while foliar Se-application increased the rice stem Se-content more than soil application.The rice Se-content was the highest in roots,but the lowest Se-content was specially in JF stems,ZY husks and NJ grains.Se-application reduced the allocation of rice grain Se-accumulation and the amount and allocation of rice root Se-accumulation in JF and increased the allocation of rice stem Se-accumulation,but this variation degree in soil Se-application was higher than in foliar Se-application.Soil Se-application reduced the arsenic content in JF roots,ZY roots,ZY stems,and NJ grains by 29.2%,46.8%,34.4%,and 44.8%,respectively,while foliar Se-application reduced the As content in ZY roots,ZY stems,and NJ grains by 35.1%,19.9%,and 34.4%,respectively.The As content in three species of rice is the lowest in rice,while the highest As content was in stems to JF,in roots under no Se-application and in husks under Se-application to ZY,in stems under no Se-application and soil Se-application and in roots under foliar Se-application to NJ.Se-application reduced the total As-absorption of three rice species and the As-absorption of NJ grains.The proportion of As-absorption by stems was the highest,especially in JF stems,where the proportion of As-absorption was over 80%.Soil selenium application increased N content in JF grain and stalk,in ZY grain,stem and root,in NJ grain and root,and P content in JF grain and stem,in ZY husk and stem,in NJ grain and stem,and the K content in three species of rice.The N content in JF stem,in all parts of ZY,in NJ husk and stem,the P content in JF grain and root,in all parts of ZY and NJ was increased by foliar selenium application,but the K content in three species of rice stem was decreased by foliar selenium application.The rice N and P content was the highest in grain,but the K content was the highest in stem.The rice N,P and K content was the lowest in husk or root,stem or husk and grain,respectively.In summary,selenium application to As polluted soil had the effects of increasing selenium,reducing arsenic and regulating the nutrient content on rice,but this effect depended on selenium application ways and rice varieties.The results of this study can provide a reference for utilizing and improving the As polluted soil and sieving rice varieties.Further research should focus on analyzing the forms of selenium and arsenic,the other pollution elements and nutrients.