The status of mineral nutrition concentration in middle leaves of flue-cured tobacco from China

Based on 410 samples collected uniformly from 2001 to 2004,covering main tobacco-planting counties of China,the concentration of N,P,K,Ca,Mg,S, Mn,Cu,Zn,B,Na,Fe,Cl in middle leaves of flue-cured tobacco were investigated.The results showed: 1) Variation coefficients of macronutrients were smaller,followed by Ca,Mg,S and micronutrients;2) Except N,Mg,S,Cu,Na,Zn and Fe,all other elements differentiate significantly among varieties.For examples,the average K concentration in K326 was 1.96%,which was significantly higher than that in Yunyan85 and Yunyan87.The average P concentration in Yunyan87 was significantly higher than that in Yunyan85 and K326;3) All elements collected from different sites showed highly significant difference.For examples,the average K concentration in tobacco leaves from Henan province was significantly lower than those from other provinces.The average Cl concentration in tobacco leaves from Guizhou province was significantly higher than those from other provinces;4) The concentration of P,K,Ca,S,B,Na conformed to normal distribution,and other elements conformed to logarithmic normal distribution,and for the concentration of N,P,K,Ca,Mg,S,Mn,Cu,Zn,B,Na,Fe and Cl,the confidence interval with 0.95 confidence level were 1.18-2.34,0.11-0.30,0.87-2.83,0.99-3.64,0.10.8,0.25-0.90,25.18-601.65,2.1-37.27,13.11-105.42,12.6-55.62,163.02-503.11,97.6384.2 and 0.07-0.53(The unit of N,P,K,Ca,Mg,S and Cl were %,others were mg/kg),respectively;5) For N,K,Cl and K/Cl,the probability of according with the international standard of high quality tobacco leaves were respectively 0.726,0.379,0.193 and 0.829,indicating that unbalance nutrient in flue-cured tobacco in China may attribute to the insufficient of nutrient in leaves.