茶树根际土壤性质及氮肥的影响

Properties of Rhizosphere Soil of Tea Plants and The Impact of Nitrogen Fertilizer

本文报导了对盆栽茶树根际土壤性质的研究结果。经外力抖落后仍粘在根系上的土壤作为根际土壤,其余土壤为非根际土壤。施氮显著降低土壤pH、交换性K、Ca、Mg含量和盐基饱和度,增加水溶性铝、有机交换态铝和吸附羟基态铝的含量。与非根际土壤相比,根际土壤pH、交换性Ca、Mg和盐基饱和度明显降低,而交换性K高于非根际土壤。根际土壤的水溶性铝、交换性铝、交换性铝饱和度和吸附羟基态铝的含量显著高于非根际土。上述结果说明茶树根际土壤明显酸化,增强了土壤铝有效度。铝在茶树根际微域环境中的这种变化,可能在茶树吸收铝的过程中起着重要作用。

The properties of rhizosphere soil of pot-cultured tea plants were investigated. The rhizosphere soil was collected by removing the soil adhering to plant roots and other soil was referred as bulk soil. N fertilization with NH4+ (urea or (NH4)2SO4) significantly reduced soil pH, the contents of exchangeable Ca, K, Mg and base saturation whereas raised extractable Al levels. Compared to bulk soil, rhizosphere soil showed lower pH, exchangeable Ca, Mg and base saturation but a higher exchangeable K. The contents of soil solution Al, exchangeable Al and absorbed hydroxy Al were much higher in the rhizosphere soil than those in the bulk soil. The results showed that the acidification of rhizosphere soil increased the availability of Al, which might be of importance for tea plants capable of taking up a large amount of Al.