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来源：雅诚德英语网
The excessively high proportion ammonium nitrogen does not avail the enhancement of tobacco leaf mean price, it is highest if matched by 75% nitric nitrogen and 25% ammonium nitrogen;
过高的比例施用铵态氮不利于烤烟均价的提高，以75％的硝态氮和25％铵态氮配施烤烟均价最高；