Pursuing robust agro-ecosystem functioning through effective soil organic carbon management

Authors: Franzluebbers, Alan

Submitted to: Carbon Management
Publication Type: Other
Publication Acceptance Date: 1/2/2013
Publication Date: 2/1/2013
Citation: Franzluebbers, A.J. 2013. Pursuing robust agro-ecosystem functioning through effective soil organic carbon management. Carbon Management. 4:43-56.

Interpretive Summary: Soil organic matter is a key indicator of many ecosystem functions, particularly in agricultural systems. With carbon as its majority constituent (~58%), the quantity of soil organic C is a key variable relating production and environmental responses. However, it is argued that depth distribution of soil organic C may be more important in understanding how agriculture affects ecosystem services derived from soil than the total quantity of soil organic C. Conservation agricultural systems lead to highly stratified soil organic C, which helps to protect soil from erosion and prevent runoff loss of nutrients (i.e. water quality improvement), creates a concentrated organic habitat for nutrient storage and soil biological diversity (i.e. soil quality improvement), and promotes a structurally stable pore network connecting surface and subsurface to avoid negative impacts on soil aeration and greenhouse gas emissions (i.e. air quality improvement). Protocols are described to allow calculation of stratification ratio of soil organic matter fractions from a diversity of sampling procedures, which may be relevant in different ecoregions and conditions of the soil.

Technical Abstract: Soil organic matter is a key indicator of many ecosystem functions, particularly in agricultural systems. With carbon as its majority constituent (~58%), the quantity of soil organic C is a key variable relating production and environmental responses. However, it is argued that depth distribution of soil organic C may be more important in understanding how agriculture affects ecosystem services derived from soil than the total quantity of soil organic C. Conservation agricultural systems lead to highly stratified soil organic C, which helps to protect soil from erosion and prevent runoff loss of nutrients (i.e. water quality improvement), creates a concentrated organic habitat for nutrient storage and soil biological diversity (i.e. soil quality improvement), and promotes a structurally stable pore network connecting surface and subsurface to avoid negative impacts on soil aeration and greenhouse gas emissions (i.e. air quality improvement). Protocols are described to allow calculation of stratification ratio of soil organic matter fractions from a diversity of sampling procedures, which may be relevant in different ecoregions and conditions of the soil.