Liu Ping, Xu Ming-Gang, Li Ju-Mei, Song Zheng-Guo, Zhang Qing
Key Laboratory of Plant Nutrition and Nutrient Cycling, Ministry of Agriculture of China, Institute of Soil and Fertilizer, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Huan Jing Ke Xue. 2008 Jan;29(1):202-6.
Effects of four kinds of potassium fertilizer (KH2PO4, K2SO4, KNO3 and KCl) in its conventional application rate as K, 0.11 g x kg(-1) on the Pb absorption by rape and speciation of Pb in paddy soil were examined by pot trial. Results showed that the Pb content in rape decreased with using KH2PO4 and K2SO4, and in the second season of pot trial for KH2PO4 treatment, Pb content in rape shoots under Pb1 (300 mg x kg(-1)) and Pb2 (500 mg x kg(-1)) level decreased by 35.6% and 45.4% respectively compared with control treatment. Applied KNO3 in soil also decreased Pb content in rape shoots to some extent, but KCl had adverse effect. At lower Pb level (300 mg x kg(-1)), KH2 PO4 and K2SO4 caused Pb in soil transformed from non-residual fractions to residual fraction substantially and for higher Pb level (500 mg x kg(-1)) only KH2PO4 application had similar effect. Under two contaminated Pb levels, exchangeable and carbonate fraction Pb in soil by using KCl were all enhanced, which indicated that KCl could promote the phytoavailability of Pb. As thus one of the most important mechanisms of potassium fertilizers influencing Pb phtoavailability was changing the speciation of Pb in soil.
通过盆栽试验研究了4种钾肥（磷酸二氢钾、硫酸钾、硝酸钾和氯化钾）按常规施钾量0.11 g·kg⁻¹施用对油菜吸收铅及稻田土壤中铅形态的影响。结果表明，施用磷酸二氢钾和硫酸钾后油菜中的铅含量降低，在盆栽试验的第二季，磷酸二氢钾处理下，铅1（300 mg·kg⁻¹）和铅2（500 mg·kg⁻¹）水平下油菜地上部的铅含量与对照处理相比分别降低了35.6%和45.4%。土壤中施用硝酸钾也在一定程度上降低了油菜地上部的铅含量，但氯化钾有不利影响。在较低铅水平（300 mg·kg⁻¹）下，磷酸二氢钾和硫酸钾使土壤中的铅从非残留态大量转化为残留态，而在较高铅水平（500 mg·kg⁻¹）下，仅施用磷酸二氢钾有类似效果。在两个污染铅水平下，施用氯化钾均提高了土壤中可交换态和碳酸盐结合态铅的含量，这表明氯化钾可促进铅的植物有效性。因此，钾肥影响铅植物有效性的最重要机制之一是改变土壤中铅的形态。
