Effects Of Nitrogen Fertilization At Different Stages On Cd Uptake And Distribution In Rice

In order to explore the effects of nitrogen fertilizer application at different growth stages on heavy metal uptake and transport in rice,this field experiment was designed:Respectively in different nitrogen fertility period,late rice variety of jade and needle xiang late indica as the experimental material,13 in 2020 along the creek town garden village in hunan liuyang plot test,the total set of four processing(F1 and F4)and a nitrogen treatment(CK),treatment 1(F1)respectively before transplanting,tillering and booting stage and full panicle stage fertilization,treatment 2(F2)before transplanting,tillering and booting stage fertilization,treatment 3(F3)only in full panicle stage fertilization,processing 4(F4)in filling stage fertilization,only the amount of nitrogen fertilizer application in every period is consistent,pure nitrogen fertilization according to 45 kg/hm2,The main research results are as follows:(1)Applying nitrogen fertilizer can increase soil p H and decrease soil available cadmium content in a short time.The dry matter accumulation and yield of the tested cultivars were the highest under N application before fertilization,tillering stage,booting stage and full heading stage,and the yield was 6.09 t/hm2 and 5.75 t/hm2,respectively,which increased by 47.46% and 730.70% compared with CK,respectively.(2)The cadmium content in brown rice of Xiangwanxian No.13 was the lowest under nitrogen application before transplanting,tillering stage and booting stage;However,the cadmium content in brown rice of Yuzhixiang was the lowest at0.04 mg/kg when nitrogen fertilizer was applied before transplanting,tillering stage,booting stage or only at full heading stage.In conclusion,F2 treatment is the most suitable fertilization period.(3)Nitrogen fertilizer application significantly increased the proportion of Cd in root cell wall and leaf organelle,and significantly increased the contents of Mn and Fe in root membrane of late rice at milkening stage,but significantly decreased the content of Cd in root membrane at milkening and maturing stage.