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作 者 ：陈世军 潘文杰 孟玉山 宗学凤 王三根

期 刊 ：植物营养与肥料学报 2012年 18卷 5期 页码：1253-1261

关键词：石灰；聚丙烯酰胺；酸性土壤；烤烟；

Keywords:lime, polyacrylamide, acid soil, flue-cured tobacco,

摘 要 ：以K326烤烟品种为材料，在土培条件下研究了石灰和聚丙烯酰胺（PAM）处理的酸性土壤对烤烟生长及生理特性的影响。结果表明：石灰和PAM处理的酸性土壤，在PAM含量低时（≤0.1%），烤烟生物量显著提高，光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）增高，根系活力增大，相对电导率和丙二醛（MDA）含量下降，但随PAM用量的增大，烤烟生长减缓。在酸性土壤中，烤烟叶片和根系的超氧化物歧化酶（SOD）、过氧化物（POD）、过氧化氢酶（CAT）活性最低；在加入石灰的土壤中，烤烟叶片和根系的三种酶活性升高，同时加入石灰和PAM的土壤，在PAM含量低时，三种酶活性下降，但随着PAM含量增高（≥0.2%），酶活性又开始上升。石灰和PAM处理的酸性土壤，土壤交换性H、交换性Al含量的改变是由石灰引起的，PAM的影响不显著；相反，石灰对土壤含水量、水势、比重、孔隙度的影响不显著，而PAM影响显著，低PAM含量时（≤0.1%），土壤含水量增加，但随PAM用量加大，土壤比重、孔隙度进一步增大，土壤含水量则逐渐降低，土壤水势显著下降。因此推测，石灰显著降低了酸性土壤交换性H、交换性Al含量，适量PAM提高了土壤孔隙度，增加土壤含水量，从而促进烤烟生长；但是当PAM过量，会导致土壤水势下降，烤烟吸水困难，其生长减缓。

Abstract:In this study, the effect of acid soils treated with lime and polyacrylamide (PAM) on the growth and physiological characteristics of K326 fluecured tobacco under soil culture conditions was investigated. The results showed that the acid soil significantly inhibited the growth of fluecured tobacco. On the acid soil treated with lime and PAM, when the PAM content was low (≤0.1%), the biomass of flue cured tobacco was significantly enhanced. The photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) also increased and root system activity was enhanced but relative conductivity and malondialdehyde (MDA) content decreased. With the increase in PAM consumption, the fluecured tobacco grew more slowly. In acid soils, the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase(CAT) of fluecured tobacco leaves and roots were at their lowest. After adding lime alone, the activities of the three enzymes increased and after adding lime with PAM, when the PAM content was low, the activity of the three enzymes declined, and with increased PAM content (≥0.2%), the enzyme activity started to rise again. In the acid soil treated with lime and PAM, the change of soil exchangeable hydrogen and exchangeable aluminum content was caused by the lime, but the influence of PAM was not significant. The influence of lime on the soil moisture content, water potential, specific gravity and porosity was not significant, but the influence of PAM on these factors was significant. The soil moisture content increased with a low PAM content (≤0.1%), but with an increase in PAM consumption, the soil specific gravity and porosity further increased, while the soil moisture contents gradually decreased and the soil water potential decreased significantly. It is conferred that the lime significantly reduced the acid soil exchangeable hydrogen and exchangeable aluminum contents, appropriately enhanced the soil porosity, increased the soil moisture content, and thus promoted the growth of flue cured tobacco. When the PAM was excessive, fluecured tobacco grew slowly, possibly because the excessive PAM caused the decrease in soil water potential and water absorption of flue cured tobacco became difficult.

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