叶面追施硝态氮肥抑制菠萝营养生长效应

采用叶面淋施的盆栽试验方法,以我国菠萝主栽品种-巴厘为试材,研究不同形态氮素对盆栽菠萝营养生长和菠萝叶片黄化的影响,为菠萝氮肥合理施用提供参考。试验结果表明,叶面淋施硝态氮处理的菠萝根、茎叶生物量显著低于叶面淋施铵态氮、酰胺态氮,黄叶数显著高于叶面淋施铵态氮、酰胺态氮。与铵态氮相比,硝态氮处理的菠萝总叶数、根数目、根重、茎叶重分别减少18.7%、26.5%、49.7%、43.5%,黄叶数增加192.7%。叶面淋施硝态氮抑制菠萝营养生长主要机理是硝态氮提高了土壤p H值,减少了铁吸收,降低菠萝叶片中全铁、活性铁、叶绿素含量(与铵态氮相比,分别减少25.9%、66.9%、23.2%)。

Effect of nitrate nitrogen on inhibiting the vegetative growth of pineapple

Based on experiment of pot cultivating with foliage spraying for main varieties of pineapple(var.yellow Mauritius),effects of nitrogen forms on the vegetative growth and chlorosis of pineapple were investigated so as to provide reference for rational application of nitrogen fertilizer for pineapple.The results showed that the biomass of roots,stem and leaves of pineapple by foliage spraying nitrate nitrogen was significantly lower than that by foliage spraying ammonium nitrogen or amide nitrogen,but the number of pineapple chlorosis leaves was more than that by foliage spraying ammonium nitrogen or amide nitrogen.Compared with ammonium nitrogen treatment,nitrate nitrogen treatment decreased total number of pineapple leaves,number of roots,the weight of roots,the weight of stem and leaves by 18.7%,26.5%,49.7%,43.5%,respectively,and increased number of yellow leaves by 192.7%.The main mechanism of nitrate nitrogen inhibiting the vegetative growth of pineapple was that nitrate nitrogen significantly increased the value of pH in soil,and significantly decreased Fe absorption and total Fe,active Fe,chlorophyll content of pineapple leaves(decreasing by 25.9%,66.9%,23.2% compared with ammonium nitrogen,respectively).