Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2020, Vol. 41 ›› Issue (3): 627-632.DOI: 10.3969/j.issn.1000-2561.2020.03.029

• Ecology • Previous Articles    

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

FU Zhilan,LU Ying()   

  1. 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
  • Received:2019-07-19 Revised:2019-08-13 Online:2020-03-25 Published:2020-04-16
  • Contact: LU Ying

Abstract:

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.

Key words: soil organic carbon, carbon fractions, land use type, mountainous area of northern Guangdong

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