田间条件下不同农艺措施对烟叶镉吸收及烟叶品质的影响

为研究不同农艺措施对烟叶镉(Cd)富集及生长发育的影响，选取中国南方植烟区两种Cd污染土壤(红泥田、黄泥田)为研究对象，以云烟87为供试品种，通过田间小区试验，研究增施磷酸二氢钾、硫酸锌、腐殖酸络合钾和生石灰对土壤Cd有效态含量、烟叶Cd含量、土壤肥力指标、烤烟经济性状及常规化学成分的影响。结果表明：与对照组相比，增施磷酸二氢钾、硫酸锌、腐殖酸络合钾和生石灰均能有效减少土壤Cd生物有效性和烟草对Cd的富集，土壤有效态Cd含量降低10.4%~25.5%，烟叶Cd消减率为20.39%~43.47%，不同处理顺序为磷酸二氢钾>腐殖酸络合钾>硫酸锌≈生石灰；施用生石灰可提高土壤pH值0.24~0.51，但会造成土壤肥力下降，影响烤烟生长发育；增施腐殖酸络合钾可提高土壤脲酶和磷酸酶活性，提高土壤有机质含量、阳离子交换量、有效氮含量等肥力指标，显著提高烤后烟叶钾含量，降低烟叶糖含量，使烟叶化学成分更趋于协调。

Effects of different agronomic practices on Cd uptake by tobacco plant and on tobacco quality under field conditions

The purpose of this study was to explore the influence of different agronomic practices on Cd uptake by tobacco cultivars and on tobacco growth. We selected two kinds of Cd-polluted soil from southern tobacco planting area (paddy soil and yellow mud) as test objects and Yunyan 87 as test cultivars for this study. We carried out field plot experiment to evaluate the effects of increasing application of potassium dihydrogen phosphate, zinc sulfate, potassium humate and lime on soil available Cd, tobacco leaf Cd, soil fertility index, economic characters and chemical composition of tobacco. The results indicated that this practice significantly decreased both Cd bioeffectiveness and accumulation in soil compared with control. These agronomic measures reduced available Cd in soil and Cd content in tobacco leaves by 10.4%25.5% and 20.39%43.47%, respectively, following the ordered of potassium dihydrogen phosphate>potassium humate>zinc sulfate≈lime in effectiveness. Increasing application of lime improved soil pH by 0.240.51 units but decreased soil fertility and affected tobacco growth. Increasing application of potassium humate, whereas, increased urease and phosphatase activities as well as organic matters, cationic exchange capacity and available nitrogen in soil. It also significantly increased the potassium content in cured tobacco leaf while decreasing its sugar content, resulting in more balanced chemical composition.