Quantitative attribution of major driving forces on soil organic carbon dynamics

Journal of Advances in Modeling Earth Systems

Yiping Wu¹  Shuguang Liu² 

[1] ASRC Federal, U.S. Geological Survey Earth Resources Observation and Science Center, Sioux Falls, South Dakota, USA;U.S. Geological Survey Earth Resources Observation and Science Center, Sioux Falls, South Dakota, USA

关键词: biofuel production;    biogeochemical modeling;    carbon dynamics;    crop rotation;    farming practices;    soil organic carbon;   

DOI  :  10.1002/2014MS000361

来源: Wiley

【 摘 要 】

Abstract

Soil organic carbon (SOC) storage plays a major role in the global carbon cycle and is affected by many factors including land use/management changes (e.g., biofuel production-oriented changes). However, the contributions of various factors to SOC changes are not well understood and quantified. This study was designed to investigate the impacts of changing farming practices, initial SOC levels, and biological enhancement of grain production on SOC dynamics and to attribute the relative contributions of major driving forces (CO₂ enrichment and farming practices) using a fractional factorial modeling design. The case study at a crop site in Iowa in the United States demonstrated that the traditional corn-soybean (CS) rotation could still accumulate SOC over this century (from 4.2 to 6.8 kg C/m²) under the current condition; whereas the continuous-corn (CC) system might have a higher SOC sequestration potential than CS. In either case, however, residue removal could reduce the sink potential substantially. Long-term simulation results also suggested that the equilibrium SOC level may vary greatly (∼5.7 to ∼11 kg C/m²) depending on cropping systems and management practices, and projected growth enhancement could make the magnitudes higher (∼7.8 to ∼13 kg C/m²). Importantly, the factorial design analysis indicated that residue management had the most significant impact (contributing 49.4%) on SOC changes, followed by CO₂ Enrichment (37%), Tillage (6.2%), the combination of CO₂ Enrichment-Residue removal (5.8%), and Fertilization (1.6%). In brief, this study is valuable for understanding the major forces driving SOC dynamics of agroecosystems and informative for decision-makers when seeking the enhancement of SOC sequestration potential and sustainability of biofuel production, especially in the Corn Belt region of the United States.

【 授权许可】

CC BY-NC-ND   
© 2014. The Authors.

Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.