Comparative analysis on the production of shixing tobacco leaf by different nitrogen forms

Shixing is an important producing area of Guangdong Luzhou-flavor tobacco. Under different ecological conditions，the effects of different nitrogen forms proportioning on the production of flue-cured tobacco are different. It is particularly important to determine the nitrogenous form proportioning fertilization method in line with the local ecological conditions according to local conditions. In this study，field experiments were conducted to investigate the effects of different N sources on the nitrogen fertilization rate. The nitrogen application rate was 165 kg/hm2 and the treatments were N1（ 100% nitrate nitrogen），N2（ 30% ammonia nitrogen + 70% nitrate nitrogen）， N3（ 50% ammonia nitrogen + 50% nitrate nitrogen），N4（ 70% ammonia nitrogen + 30% nitrate nitrogen） and N5 （100% ammonia nitrogen） The effects of flue-cured tobacco on the fertility process，agronomic and economic characters and chemical composition of flue-cured tobacco were analyzed. The results showed that：（1） Nitrate promoted tobacco plants grow quicker，the growth process accelerated，mainly in the shortened rooting stage. With the increase of the proportion of nitrate nitrogen，the field growth period of flue-cured tobacco tended to shorten. （2） When the proportion of ammonium nitrogen increased，the main agronomic characters of tobacco plant was significantly different in the resetting stage，whereas the major agronomic traits and differences budding stage and dome stage of tobacco was not obvious. （ 3） The optimal performance of the economic characters of flue-cured tobacco leaves under the condition of 50% nitrate nitrogen and 50% ammonium nitrogen ratio.（4） The ratio of 30% nitrate nitrogen and 70% ammonium nitrogen，50% nitrate nitrogen and 50% ammonium nitrogen was beneficial to the accumulation of petroleum ether extract. The results showed that nitrate nitrogen promoted the rapid emergence and rapid growth of tobacco plants in early growth，and the appropriate ratio was conducive to the performance of economic traits and the coordination of chemical components.