不同林龄Ⅰ-69杨根际土离子浓度和养分状况  

Ion and Nutrient Status in Rhizospheres of Poplar Stands at Different Ages

作　　者：丁应祥[1] 王福升[1] 林寿明 

机构地区：[1]南京林业大学森林资源与环境学院

出　　处：《林业科学研究》1998年第5期461-468,共8页Forest Research

基　　金：国家"八五"攻关项目

摘　　要：采用掘根抖落法收集根际土，研究江苏省东台市林场盐渍化土壤上１－６９杨根际土的矿质离子和养分状况。结果表明，根际土与非根际土有差异。根际土中矿质离子的总量比非根际土高，由大到小的顺序为：３年生林分、６年生林分、１２年生林分。各林龄的林分中，Ｋ＋在根际土中均明显地富积。就全土层平均值而言，Ｎａ＋、Ｃａ２＋、Ｍｇ２＋、ＳＯ４２－在３年生林分的根际土中有较显著的富积，在６和１２年生林分中则变化不明显；但在表土层的根际土中，Ｎａ＋、Ｃａ２＋、ＳＯ４２－有一定富积；其它离子如Ｍｇ２＋、ＨＣＯ３－、Ｃｌ－则变化不明显。所有林分中，根际土的ｐＨ都低于非根际土，水解Ｎ、速效Ｐ、水溶性Ｋ则有显著富积。This project was aimed to study the amount of ions and some nutrients in the rhizospheres of hybrid poplar ( Populus deltoides Bartr. cv. ‘Lux’). Three poplar stands at different ages (3,6,12 years old) were located in Dongta Forest Farm (8 km away from the Yellow Sea),Dongtai City,Jiangsu Province. Samples of rhizospheres were taken from the topsoil (0～20 cm) and subsoil (21～40 cm) under three average trees of each stand. The total ion in rhizospheres is higher in all stands. In most rhizospheres, ion accumulations were statistically obvious. Higher ion accumulations in subsoil rhizospheres were associated with stronger water absorbing function of the deep root,the nutrient absorbing function of the root in topsoil made the ion accumulation at a low rate.The accumulation of K + in rhizosphere was the highest and the most obvious one in all the ions. K + accumulation in rhizospheres of trees on salty soil were possibly induced by the excessive K + transported to the rhizospheres by mass flow. Na + was obviously accumulated in some rhizospheres. Ca 2+ and Mg 2+ did not vary greatly between rhizospheres and non rhizospheres. The differences of HCO 3 - fluctuated within 10% between rhizospheres and non rhizospheres. Cl - was accumulated in rhizospheres in summer and in topsoil, but not in other conditions. SO 4 2- was not highly accumulated in the rhizospheres of the most stands. Soil pH of rhizospheres in all sites were lower than those of the non rhizospheres. In subsoil,a greater decrease of pH in the rhizospheres were observed comparing with the topsoil. Hydrolysable N,available P and soluable K were found accumulated in all sites.

关 键 词：杨树 海滨盐渍土 根际土 矿质离子 养分 

分 类 号：S792.11[农业科学—林木遗传育种]