氮肥形态、用量和种植密度对香料烟光合作用的影响

在云南保山香料烟产区,通过田间试验研究了不同氮肥形态、用量和种植密度对香料烟光合作用和硝酸还原酶活性的影响。结果表明,与仅施用铵态氮相比,在氮肥中增加一定比例的硝态氮更有利于提高香料烟的叶绿素含量、硝酸还原酶活性和光合速率。综合研究结果表明,以硝态氮∶铵态氮=1～2∶1较好;在同一栽培密度下,随着氮肥用量的增加香料烟叶绿素含量和硝酸还原酶活性均有提高,在同一氮肥用量条件下,叶绿素含量变化无明显规律,但硝酸还原酶活性随密度的减小而增大;在所有处理中以中等密度和中等施氮量的处理A2B2光合速率最高。

Effects of Nitrogen Forms,Rates and Plant Population on Photosynthesis of Oriental Tobacco

The effects of nitrogen forms,rates and plant population on photosynthesis and nitrate reductase (NR) (activities) of oriental tobacco were investigated in Baoshan oriental tobacco growing areas of Yunnan Province. The results showed that applying nitrogen with a blend of NO_3~--N and NH_4~ -N while comparing with applying NH_4~ -N only, was more conducive to raising the content of chlorophyll, NR activities and photosynthesis rate. The preferable ratio of NO_3~--N to NH_4~ -N was 1-2 to 1. With the same plant population, the content of chlorophyll and NR activities were increased by increasing nitrogen rates. With the same nitrogen rates, no rule was found in the change of chlorophyll content, while NR activities were decreased by increasing plant population. The treatment of medium nitrogen application rates and plant population (A2B2) obtained the highest photosynthesis rate.