Effects Of Water And Fertilizer Integration Technology On Absorption And Migration Of Potassium And Chloride Ions In Flue-Cured Tobacco

Taking flue-cured tobacco as the research object and aiming at improving potassium and reducing chlorine,this study conducted a plot comparison test and field verification during 2021-2022 in Xiangyun County,Dali City,Yunnan Province,to study the effects of water-fertilizer integration technology on soil potassium and chlorine content,on the absorption and migration of potassium and chloride ions in various organs during the growth and development of flue-cured tobacco,and on the tobacco quality after roasting.On this basis,the effects of different potassium fertilizer application on potassium channel gene expression were studied.The main research results are as follows:1、The Effect of Integrated Water and Fertilizer Technology on Soil Potassium and Chlorine Content.The integrated technology of water and fertilizer may promote the migration of potassium ions from the 20-40 cm soil layer to the 0-20 cm soil layer after transplanting flue-cured tobacco,and promote the migration of chloride ions from the0-20 cm soil layer to the 20-40 cm soil layer.The integrated treatment of water and fertilizer with weight loss of 10%,15%,and 20% all increased the accumulation amount and rate of soil potassium in flue-cured tobacco from 60 to 90 days after transplantation,but there were differences in the main action time.The integrated treatment of water and fertilizer for weight loss of 15% and 20% may promote the migration of chloride ions to deep soil during the 60-75 days after transplanting of flue-cured tobacco,and the accumulation amount and rate of soil chlorine are lower than those of CK treatment.This may be during this period when the integrated technology of water and fertilizer promotes the migration of chloride ions to deep soil.2、Effect of integrated water and fertilizer technology on potassium and chlorine content in various organs of flue-cured tobacco during its growth period.The study results in 2021 showed that the potassium content of flue-cured tobacco leaves at 90 d after transplanting was reduced by 49.38% compared with 40 d after transplanting,which was significantly lower than CK treatment.The combined treatment with 10% weight loss reduced the chlorine content of leaves by 13.07%,and the proportion of chloride ions in the total chloride ions of leaves was significantly lower than that of CK;The results of the study in 2022 showed that the potassium content of flue-cured tobacco leaves at 90 d after transplantation was reduced by 65.23% and 64.45% respectively by 10% weight loss and 20%water-fertilizer integrated treatment compared with 30 d after transplantation,which was lower than CK treatment but not significant.The chlorine content of leaves at20% weight loss was reduced by 50.53%.The decrease was significantly higher than that of CK treatment.The contents of potassium and chlorine in stems and roots of different treatments and their proportions in total potassium and chloride ions of tobacco plants were not consistent in the whole growth period.The integration of water and fertilizer technology may promote the accumulation amount and accumulation rate of potassium in flue-cured tobacco plants 60 to 90 days after transplanting.The integration technology of water and fertilizer reduction effectively reduces the accumulation amount and accumulation rate of chlorine in leaves during the growth period of flue-cured tobacco,and the integration technology of water and fertilizer reduction of 10% May promote the migration of chloride ions to other organs in leaves.3、Effects of Different Potassium Fertilizers on the Expression of Potassium Ion Channel Genes in Flue-cured Tobacco under the Integrated Technology of Water and Fertilizer.Under the integrated conditions of water and fertilizer,the application of potassium dihydrogen phosphate,potassium pyrophosphate,and potassium fulvic acid significantly promoted the expression of potassium ion channel genes.65 days after transplanting,the relative expression levels of NtNHX2 and NtHAK genes induced by the application of potassium dihydrogen phosphate were 1.67 and 4.27,respectively.The relative expression levels of NtHAK genes induced by the application of potassium pyrophosphate were 2.25,and the relative expression levels of NtNHX2 and NtHAK genes induced by the application of potassium fulvic acid were 2.25 and4.27,respectively The relative expression levels of NtHAK and NtKC1 genes were3.46,3.77,and 2.56,respectively;After 90 days of transplanting,the relative expression levels of NtKC1 gene in T2 and T3 treatments were 7.98 and 2.15,respectively.4、The Effect of Integrated Water and Fertilizer Technology on the Quality of Flue-cured Tobacco.After being treated with integrated water and fertilizer technology,the potassium chloride content in the upper and middle leaves of the 20% weight loss integrated water and fertilizer treatment increased by 225.00% and 176.43%,respectively,and effectively improved the aroma characteristics,taste characteristics,smoke characteristics,and other indicators of the cured tobacco;The integrated treatment of water and fertilizer for weight loss of 15% increased the potassium and chlorine content in the lower leaves by 136.07% compared to CK,significantly improving the aroma characteristics,smoke characteristics,taste characteristics,and other indicators of the middle leaves of cured tobacco.