粤北山区不同土地利用方式下土壤有机碳及其组分特征  

Characteristics of Soil Organic Carbon and Its Fractions under Different Land Uses in Northern Guangdong

作　　者：付志蓝 卢瑛[1] FU Zhilan;LU Ying(College of Natural Resources and Environment,South China Agricultural University/Key Laboratory of Arable Land Conservation in South China,Ministry of Agriculture and Rural Affairs/Guangdong Province Key Laboratory of Land Use and Consolidation,Guangzhou,Guangdong 510642,China)

机构地区：[1]华南农业大学资源环境学院/农业农村部华南耕地保育重点实验室/广东省土地利用与整治重点实验室,广东广州510642

出　　处：《热带作物学报》2020年第3期627-632,共6页Chinese Journal of Tropical Crops

基　　金：国家科技基础性工作专项重点项目(No.2014FY110200);国家自然科学基金项目(No.41271233)。

摘　　要：土壤碳库影响土壤肥力和全球气候变化,土壤有机碳及其组分能够敏感地反映土壤碳库的变化。研究不同土地利用方式下土壤有机碳及其组分特征对指导土壤资源的合理利用与管理具有重要意义。采集粤北山区6种土地利用方式(林地、茶园、果园、弃耕地、水田、水旱轮作)的表层土壤(0~20 cm),测定土壤有机碳(SOC)及其易氧化有机碳(EOC)、颗粒有机碳(POC)、胡敏酸碳(HAC)、富里酸碳(FAC)和胡敏素碳(HMC)等组分,分析SOC及其组分对不同土地利用的响应以及SOC各组分之间的关系。研究结果表明:(1)水田和林地土壤SOC含量(16.70和16.42 g/kg)比茶园、果园和弃耕地土壤分别高出28.86%和26.99%、21.54%和20.56%、37.79%和35.48%(P<0.05);(2)水田土壤EOC(4.83 g/kg)、HAC(2.81 g/kg)、胡/富比(0.83),HAC占SOC比例(16.80%)显著高于其他5种利用方式土壤;而林地土壤FAC(5.01 g/kg)含量显著高于其他5种利用方式土壤;(3)SOC与EOC、fPOC、POC、HAC、FAC、HMC呈显著正相关。综上所述,粤北山区HMC是土壤有机碳优势组分,土壤有机碳各组分含量随着有机碳含量增加而增加。种植水稻和林业利用有利于SOC的积累,可增加土壤有机碳库、提高土壤肥力。Soil carbon pool affects soil fertility and global climate change. Soil organic carbon and its fractions are sensitive indicators of changes in soil carbon pool. Therefore,the study on soil organic carbon and its fractions under different land uses is of great significance to guide reasonable utilization and management of soil resource. Topsoil samples(0~20 cm) were collected under six land uses(woodland, tea garden, orchard land, abandoned land, paddy field and paddy-upland rotation) in northern Guangdong, soil organic carbon(SOC) and its fractions including easy oxidation of organic carbon(EOC), particulate organic carbon(POC), humic acid C(HAC), humic acid C(FAC) and humin C(HMC) were determined. The respond of SOC and its fractions to different land uses and the relationship among SOC fractions were evaluated. SOC in paddy field(16.70 g/kg) and woodland(16.42 g/kg) was the highest, which was 28.86% and 26.99%, 21.54% and 20.56%, 37.79% and 35.48% higher compared with tea plantations, orchards and abandoned farmland respectively, with significant difference(P<0.05).(2) Soil EOC(4.83 g/kg), POC(0.98 g/kg), HAC(2.81 g/kg). The ratio of HAC to FAC(0.83), the proportion of HAC to SOC(16.8%) in paddy field and FAC in wood land were significantly higher than the other five land uses. SOC was significantly positively correlated with EOC, fPOC, POC, HAC, FAC and HMC. Therefore, in mountainous areas of northern Guangdong, humin C was the dominant fraction of SOC, and the content of SOC fractions increased with the increase of SOC content. Rice planting and woodland utilization are beneficial to SOC accumulation, and can increase soil organic carbon pool and improve soil fertility.

关 键 词：土壤有机碳 有机碳组分 利用方式 粤北山区 

分 类 号：S153.6[农业科学—土壤学]