不同甜菜品种根际钾吸收特性的研究

The Characteristics of Uptaking Potassium in the Rhizosphere of Different Sugar Beet Varieties

采用微型盆钵和根际土壤薄层切片法对甜菜不同品种的钾吸收特性进行了研究，结果表明甜菜能强烈地吸收根近区土壤中的钾素，形成一明显的根近区的土壤钾素的耗竭剖面，其剖面变化特征因品种、培养时间和土壤肥力条件而变化。在品种相同时根际各相关的K吸收能力参数随培养时间延长和土壤肥力的提高而增加，在培养时间和土壤肥力条件相同条件下，品种Elan根际的吸钾能力明显高于Coilbri，其根际土壤的钾素耗竭范围、单位根长的耗竭土体体积及总吸钾量分别在9．4～24．7mm，2．78～19．2cm3／cm及0．96～4．99mg／盆范围内，比后者分别高出7％～28％、14％～64％和16％～17％。施钠对甜菜根际的吸钾特性的影响因品种而异，在土壤供钾适宜的条件下，钠肥有降低品种Elan的吸钾能力而改善品种Colibri对钾素的吸收作用。

Potassium depletion in the rhizosphere of different sugar beet varieties wes stutied by the use of mini pot and soil slicing method. The results showed that the sugar beet seedlings could intensively uptake soil K form a depletion profile in the rhizosphere,which alternated itself as the variety,cultivating time and soil fertility changed. The related parameters of K uptake in the rhizosphere were increased as the cultivating time and soil fertility increased.The soil K depleted range,depleted soil volume per unit root and the total uptaked K in variety Elan were 7 % ~ 28 %, 14 % ~ 64 % and 16 % ~ 17 % higher than that of Colibri,respectively. Sodium application had a different effects on the K uptake ability of sugar beet varieties which were used in this investigation. Under the base of adequate soil K concentration Na fertilizer had a trends to decrease the K uptake ability of Elan,but improved the K uptake ability of Colibri.