Effects of Phosphate Fertilizer on the Content of Nitrate and Nitrite in Flue-cured Tobacco

Effects of the applied rates of phosphate fertilizer on nitrate nitrogen content in flue-cured tobacco were studied.The results indicated that the contents of nitrate and nitrite decreased with the increase of applied rate of phosphate fertilizer in a certain range.The nitrate content of fresh leaf was obviously lower than that of cured leaf, and had highly significant positive correlation with the content of nitrate and nitrite in cured leaf.The change of nitrate and nitrite contents showed the same trend among different leaf positions, but the contents of nitrate and nitrite in cutters were higher than those in upper leaves.No significant correlation between the amount of phosphate fertilizer and the contents of nicotine, total nitrogen, protein, and other chemical components containing nitrogen was found.