Effects Of The Ratio Of Base Fertilizer And Topdressing And The Ratio Of Ammonium Nitrogen And Nitric Nitrogen In Topdressing On Flue-cured Tobacco

Different ratio of base fertilizer and topdressing and different ratio of ammoniumnitrogen and nitric nitrogen in topdressing have a pronounced effect on the growth,development and yield, value of flue-cured tobacco (Nicotiana tabacum L.). This studywas conducted in 2005 in Changning City of Hunan province. The 9 treatments were:(T1) In the ratio of base fertilizer and topdressing was 30% :70%, in the ratio ofammonium nitrogen and nitric nitrogen in topdressing was 100% ammonium nitrogen(A3B7++), (T2) In the ratio of base fertilizer and topdressing was 30% :70%, in theratio of ammonium nitrogen and nitric nitrogen in topdressing was 50% ammoniumnitrogen plus 50% nitric nitrogen (A3B7+-), (T3) In the ratio of base fertilizer andtopdressing was 30% :70%, in the ratio of ammonium nitrogen and nitric nitrogen intopdressing were 100% nitric nitrogen(A3B7--), (T4) In the ratio of base fertilizer andtopdressing was 50% :50%, in the ratio of ammonium nitrogen and nitric nitrogen intopdressing was 100% ammonium nitrogen(A5B5++), (T5) In the ratio of base fertilizerand topdressing was 50% :50%, in the ratio of ammonium nitrogen and nitric nitrogenin topdressing was 50% ammonium nitrogen plus 50% nitric nitrogen (A5B5+-), (T6) Inthe ratio of base fertilizer and topdressing was 50% :50%, in the ratio of ammoniumnitrogen and nitric nitrogen in topdressing was 100% nitric nitrogen (A5B5--), (T7) Inthe ratio of base fertilizer and topdressing was 70% :30%, in the ratio of ammoniumnitrogen and nitric nitrogen in topdressing was 100% ammonium nitrogen(A7B3++),(T8) In the ratio of base fertilizer and topdressing was 70% :30%, in the ratio ofammonium nitrogen and nitric nitrogen in topdressing was 50% ammonium nitrogenplus 50% nitric nitrogen (ATB3+-), (T9) In the ratio of base fertilizer and topdressingwas 70% :30%, in the ratio of ammonium nitrogen and nitric nitrogen in topdressingwas 100% nitric nitrogen (A7B3--). The results showed that the plant height, girth, thepitch and the leaf area of T2( A3B7+-) were greater than that of other treatments, whilethe value, the average price ofT8 (A7B3+-) were highest among all treatments.