Effects of different nitrogen forms on the growth, photosynthesis, yield and quality of tobacco | 铵硝氮配比对烤烟生长生理及产量和品质的影响

Chinese. 研究不同铵硝比对烤烟生长的影响，为优质烤烟生产中肥料的合理施用提供参考。采用田间单因素试验的方法，设N1（铵硝质量比100∶0）、N2（75∶25）、N3（50∶50）、N4（25∶75）、N5（0∶100）5个处理，以吉烟9号为材料，研究不同铵硝比对烤烟生长、光合特性、抗氧化酶活性、经济性状、烤后烟化学成分和中性致香物含量的影响。（1）硝态氮及其比例较高的N4和N5处理烟株前期生长较快，铵态氮及其比例较高的N1、N2处理烟株后期生长较快，N3处理可使烟株持续稳定生长，尤其以叶片生长较快。（2）铵硝态氮配施可不同程度增加烟叶叶绿素含量，提高净光合速率，增强SOD和CAT活性，降低MDA含量，延长叶片生理功能期，其中N3处理烟叶的SOD、CAT活性最高，MDA含量最低，叶绿素和净光合速率也最高。（3）与纯施铵态氮相比，硝态氮比例增大，烟叶产量、产值、均价、上等烟比例明显升高，N3处理烤烟综合经济性状最优，若再增大硝态氮比例，其综合经济性状变差。（4）N3处理烟叶水溶性糖、还原糖含量明显较低，烟碱和钾素含量明显较高，各处理总氮、蛋白质和氯含量均在适宜范围之内。（5）不同铵硝比导致烟叶致香物质含量有所差异，N3处理烟叶的新植二烯含量较低，但除新植二烯外的致香物质含量、致香物质总量相对较高。综合分析认为，N3处理有利于烟株稳定生长和叶面积增大，且烟叶膜脂质过氧化水平较低，化学成分和致香物质的组成较为协调，使烤烟产量和品质协同提高，说明在优质烤烟生产中，铵态氮和硝态氮各50%配合施用效果较好。

English. The effects of different ratios of ammonium to nitrate nitrogen on the growth of tobacco was studied to provide a theoretical basis for reasonable use of fertilizers. The single factor experiment was applied with different ratios of NH4+-N/NO3--N:N1(100∶0),N2(75∶25),N3(50∶50),N4(25∶75), and N5(0∶100)in the field experiment. Jiyan No.9 was taken as medium to study the effects of NH4+-N/NO3--N on tobacco growth, photosynthesis, activity of antioxidase, chemical composition,neutral aroma component and economic characteristics of flue-cured tobacco leaves. (1)The treatments N4 and N5 with a high proportion of NH4+-N/NO3--N grew faster in the earlier stage, while the treatments with more NH4+-N amount(N1 and N2)grew faster in later stage. The N3 treatment grew stably all the time with the NH4+-N/NO3--N ratio of 50∶50.(2)A suitable RN represented by N3 could increase chlorophyll content, improve the net photosynthetic rate and the activities of SOD and CAT, and reduce MDA content which could prolong tobacco physiological function period. (3)Compared with treatment with ammonium nitrogen only, a greater proportion of nitrate nitrogen applied, the tobacco yield, production value, average price, and fine tobacco leaves ratio all were enhanced significantly. The comprehensive economic profits of N3 treatment was the best. The economic profits decreased if nitrate nitrogen proportion continued to increase. (4)The soluble sugar and reducing sugar contents of tobacco leaves of N3 treatment was quite low, while alkaline and potassium contents were obviously high. However, total nitrogen, protein and chlorine contents were all within their suitable ranges. (5)The contents of aroma components of different treatments were distinct. The amounts of total aroma components and each aroma component of N3 treatment(RN of 50∶50)were relatively higher compared to other treatments, except for neophytadiene. In total,the N3 treatment with a RN of 50∶50 could contribute to the growth of tobacco,increase of leaf area, harmonize the constituent of chemical components and aroma components while prevent tobacco leaf membrane lipid from peroxidation. The ammonium to nitrate ratio of 50∶50 was considered to be the most effective for the improvement of tobacco yield and quality simultaneously.