Effect of nitrogen and potassium ratio on chemical components in tobacco leaves grown in cinnamon soil

Experiments to address the effect of N:K ratio on chemical components in tobacco leaf were carried out. Results showed that 1) Treatment with N:K_2O ratio of 1:2 can increase weight of tobacco leaves and reduce nicotine level under condition of abundant nitrogen application, whereas treatment with N:K_2O ratio of 1:1 can result in high level of nicotine and total nitrogen. 2) Under condition of zero potash application, the potassium level in tobacco leaves with less nitrogen fertilization was higher than that with more nitrogen fertilization. With potash application and the same ratio of N and K, higher nitrogen fertilization can result in higher K accumulation. N can promote K absorption for tobacco grown in cinnamon soil. 3) An increasing potassium content and decreasing Ca and Mg contents were observed with increase in potash application. 4) Potassium content in tobacco leaves was significantly negatively correlated with Ca and Mg contents, and there existed intensive antagonism of Ca and Mg to K. Potassium content in tobacco leaves was positively correlated with active potassium content in soil and the correlation was highly significant.