临安山核桃林地土壤磷素状况及其淋失风险分析

摘要

In this paper , 50 top soil samples ( 0-20 cm ) were collected from Chinese hickory ( Carya cathayensis Sarg.)orchards located at Daoshi and Tuankou towns of Lin'an City, Zhejiang Province, to assess the potential risk of phosphorus ( P) leaching induced by long-term fertilizer application .Soil analysis showed that soil Olsen-P had a great spatial variability , being 0-89.3 mg· kg-1 .Analysis of correlations between Olsen-P and CaCl 2-P showed that the critical values ( change-point) of soil Olsen-P in Daoshi and Tuankou towns were 19.3 and 29.3 mg· kg -1 , re-spectively .Soil Olsen-P exceeding the critical values accounted for 30% and 45% of all the investigated orchards , respectively, in Daoshi and Tuankou towns .%以天目山地区临安市岛石镇下塔村和湍口镇湍口村发育于石灰岩的山核桃林地土壤为研究对象，采集林地表层（0～20 cm）土壤样品，用于评估长期施肥对山核桃林地土壤磷素状况的影响及其潜在的淋失风险。土壤分析表明：土壤Olsen-P存在较大的空间变异，含量低的近于0 mg· kg-1，而最高的含量达89.3 mg· kg-1。土壤CaCl2-P与Olsen-P相关分析显示，岛石镇和湍口镇土壤Olsen-P的临界值分别为19.3和29.3 mg· kg-1。据此，岛石和湍口两地土壤发生磷淋失的林地分别占调查林地的30％和45％。表明研究区已经有相当数量的山核桃林地因土壤磷素积累而存在淋失风险，需要引起重视。