营养液pH值对烟草苗期矿质营养吸收与积累的影响

Effect of Nutrient Solution pH Value on Absorption and Accumulation of Mineral Nutrients during Tobacco Seedling Stage

采用营养液培养的方法,研究了不同pH值营养液对烟草主要几种矿质养分的吸收与积累的影响。结果表明,在营养液养分形态与浓度一致条件下,当营养液的pH值由4.5升到8.5时,烟草生长量呈倒抛物线型变化,在pH值为6.5时烟株干物质积累量最大。随营养液pH值的升高,烟草全株和叶片氮含量均呈抛物线趋势变化,以营养液pH值为7.5时含量最低;烟草全株和叶片磷、锌、铜、锰含量随营养液pH值升高而明显下降,呈负相关关系;钾、钙、镁含量总体上随营养液pH值的提高而增加,呈正相关关系。氮、磷、钾、钙、镁、锌、铜等在烟草全株和叶片的积累量变化趋势相同,随pH值的升高呈倒抛物线型变化,基本上都是以营养液pH值为5.5～6.5时积累量达到最大值;而锰积累量均随营养pH值的升高而下降,呈负相关关系。可见,适宜的营养液pH值可促进烟株干物质积累,并影响烟株矿质营养的含量和积累量,从而影响烟叶产量和品质。

The effect of soil pH value on the mineral nutrient absorption and accumulation of tabacco was stud- ied by the method of nutrient solution culture. The results showed that,under the consistant condition of nutrient so- lution component and concentration,the tobacco biomass varied in a shape of parabola with the nutrient solution pH value changes from 4.5 to 8.5 ,and reached the peak value at pH 6.5. The N content in whole plant and leaves of tobacco also changed in parabola with the increase of nutrient solution pH value, and got a Min-peak value at pH 7.5. The P,Zn,Cu and Mn contents in plant and leaves decreased with the increase of solution pH value,but the K, Ca, and Mg contents increased with the pH value rising. The accumulation amount in plant and leaves of N, P, K, Ca,Mg,Zn,Cu all varied in a shape of parabola with the pH value increased and got a peak value at pH 5.5 -6.5, while the accumulation amount of Mn decreased with the increase of pH value,presenting a negative correlation. So, appropriate nutrient solution pH value could promote tobacco dry matter weight accumulation and affect the mineral adsorption and accumulation in tobacco,and affect tobacco leaves yield and quality.