Regional Simulation of Soil Organic Carbon Dynamics for Dry Farmland in East China by Coupling a 1:500000 Soil Database with the Century Model  

作　　者：WANG Shi-Hang SHI Xue-Zheng ZHAO Yong-Cun D. C. WEINDORF YU Dong-Sheng XU Sheng-Xiang TAN Man-Zhi SUN Wei-Xia 

机构地区：[1]State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing210008 (China) [2]Louisiana State University AgCenter, Baton Rouge, Louisiana 70803 (USA) [3]Graduate University of Chinese Academy of Sciences, Beijing 100049 (China)

出　　处：《Pedosphere》2011年第3期277-287,共11页土壤圈（英文版）

基　　金：Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (Nos.KZCX2-YW-Q1-07 and KZCX2-YW-Q1-15);the National Basic Research Program (973 Program) of China (No.2010CB950702);the National Natural Science Foundation of China (No.40921061)

摘　　要：Changes in soil organic carbon (SOC) in agricultural soils influence soil quality and greenhouse gas concentrations in the atmosphere. Dry farmland covers more than 70% of the whole cropland area in China and plays an important role in mitigating carbon dioxide (CO2) emissions. In this study, 4109 dry farmland soil polygons were extracted using spatial overlay analysis of the soil layer (1:500000) and the land use layer (1:500000) to support Century model simulations of SOC dynamics for dry farmland in Anhui Province, East China from 1980 to 2008. Considering two field-validation sites, the Century model performed relatively well in modeling SOC dynamics for dry farmland in the province. The simulated results showed that the area-weighted mean soil organic carbon density (SOCD) of dry farmland increased from 18.77 Mg C ha1 in 1980 to 23.99 Mg C ha1 in 2008 with an average sequestration rate of 0.18 Mg C ha1 year?1. Approximately 94.9% of the total dry farmland area sequestered carbon while 5.1% had carbon lost. Over the past 29 years, the net SOC gain in dry farmland soils of the province was 19.37 Tg, with an average sequestration rate of 0.67 Tg C year1. Augmentation of SOC was primarily due to increased consumption of nitrogen fertilizer and farmyard manure. Moreover, SOC dynamics were highly differentiated among dry farmland soil groups. The integration of the Century model with a fine-scale soil database approach could be conveniently utilized as a tool for the accurate simulation of SOC dynamics at the regional scale.Changes in soil organic carbon （SOC） in agricultural soils influence soil quality and greenhouse gas concentrations in the atmosphere. Dry farmland covers more than 70% of the whole cropland area in China and plays an important role in mitigating carbon dioxide （CO2） emissions. In this study, 4 109 dry farmland soil polygons were extracted using spatial overlay analysis of the soil layer （1：500 000） and the land use layer （1：500 000） to support Century model simulations of SOC dynamics for dry farmland in Anhui Province, East China from 1980 to 2008. Considering two field-validation sites, the Century model performed relatively well in modeling SOC dynamics for dry farmland in the province. The simulated results showed that the area-weighted mean soil organic carbon density （SOCD） of dry farmland increased from 18.77 Mg C ha-1 in 1980 to 23.99 Mg C ha-1 in 2008 with an average sequestration rate of 0.18 Mg C ha-1 year-1. Approximately 94.9% of the total dry farmland area sequestered carbon while 5.1% had carbon lost. Over the past 29 years, the net SOC gain in dry farmland soils of the province was 19.37 Tg, with an average sequestration rate of 0.67 Tg C year-1. Augmentation of SOC was primarily due to increased consumption of nitrogen fertilizer and farmyard manure. Moreover, SOC dynamics were highly differentiated among dry farmland soil groups. The integration of the Century model with a fine-scale soil database approach could be conveniently utilized as a tool for the accurate simulation of SOC dynamics at the regional scale.

关 键 词：agricultural soils C02 emissions greenhouse gas soil organic carbon density soil quality 

分 类 号：S153.6[农业科学—土壤学] S159.2[农业科学—农业基础科学]