不同植被对红壤养分含量及吸附-解吸 性能的影响

植被类型和生长状况, 对土壤养分和土壤对 H2PO4- 的吸附-解吸及对 K +的缓冲特性均具有较大影响。 草灌 乔植被下土壤中氮磷钾等养分的含量均较高, 白茅植被下土壤有机质含量较高(21.16g/ kg), 无植被处理下土壤有 机质和养分含量均较低。 3 种类型植被下, 土壤对 H2PO4-吸附的 b 值以无植被>白茅>草灌乔, 不同 H2PO4- 吸附 范围内的解吸率以草灌乔相对较高, 而无植被处理下则相对较低 ;对 K +缓冲的 Q/ I 曲线参数比较, Δk0 值以草灌 乔>白茅>无植被, AR0 值为白茅>无植被>草灌乔, PBCk 值为无植被>白茅>草灌乔。

Effects of vegetation types on soil nutrient contents and adsorb-desorption of red soil

The vegetation types affected the nutrient contents of red soil firstly and then the adsorb desorption of H₂PO₄^- and the buffering capacity of K⁺ by the red soil. There were higher nutrient contents of NPK etc. in herb shrub trees vegetation, and the higher content of OM in vegetation of cogongrass (Imperata cylindrical var. major), and the lowest contents of NPK and OM in no vegetation. Compared the three treatments, there was decreased from treatments of no vegetation, vegetation of cogongrass to herb shrub trees vegetation by the b value of H₂PO₄^- adsorption by soil, and there was opposite tendency by desorption of H₂PO₄^- in same desorption scope. Compared the parameters of K⁺ buffering Q/I curve the ΔK₀ value decreased from herb shrub trees vegetation, vegetation of cogongrass to no vegetation, and the AR₀ value was from the vegetation of cogongrass, no vegetation to herb shrub trees vegetation, and the PBC_k value was no vegetation, vegetation of cogongrass to herb shrub trees vegetation in three treatments.