不同树龄橡胶林土壤养分变化特征及对细根的影响

通过用根钻法对幼树期（5a）、初产期（9a）和旺产期（16a）3个树龄橡胶林土壤养分变化特征及对橡胶树细根影响的研究。结果表明：在橡胶林0~60cm土层的土壤中,5a橡胶林土壤肥力相对比9a、16a橡胶林的高,9a橡胶林肥力相对较低,土壤养分随着土层增加而减少,不同土层养分含量各有差异。不同树龄橡胶树细根生物量,与土壤养分有不同程度的相关性。典型相关分析表明,除了受树龄影响外,橡胶树细根生物量主要还受以有机质、全氮、速效磷等养分为代表的土壤肥力的影响,在一定的条件下,创造合适的土壤肥力条件是确保橡胶树细根高生长量、高吸收效率和养分循环的基本保证。

Variation Characteristics of Soil Environment and Its Effect on Hairy Roots of Hevea brasiliensis at Different Ages

The soil nutrients in rubber plantations at 3 ages,5 years old (immature stage),9 years old (early yielding stage) and 16 years old(premium yielding stage),were detected and the growth of hairy roots of rubber trees (Hevea brasiliensis) were observed by using sequential root coring method. The results showed that soil fertility of rubber trees at the age of 5 years old was comparatively higher in soil layers 0～60 cm deep than that of the rubber trees at the ages of 9 years old and 16 years old,while the soil fertility of the rubber trees at the age of 9 years old was relatively lower. Soil nutrients decreased with soil depth and the soil nutrient content varied with soil layers. The biomass of hairy roots of rubber trees at different ages was correlated to some extent with soil nutrients. Correlation analysis indicated that biomass of hairy roots of rubber trees was affected mainly by elements of soil fertility such as organic matters,total nitrogen,and available phosphorus,besides tree age. Under given conditions,providing rubber tree with suitable soil fertility should be a basic guarantee to ensure higher biomass of hairy roots and high absorption efficiency and cycling of soil nutrients.