Examining the paired comparison method approach for determining soil organic carbon sequestration rates

Excerpt

In recent years, researchers have published soil organic carbon (SOC) sequestration rates for conventional tillage (CT) and no-tillage (NT) systems. Determining SOC sequestration is a very challenging and complex issue, especially when it involves highly dynamic systems such as climate and agroecosystems. The monitoring of soil organic matter (SOM) change is important to determine the sustainability of soil health and productivity as we face some daunting challenges in climate change. Improvement in SOC sequestration is an integrative process of atmosphere-plant-soil that has been widely documented in the literature (e.g., Franzluebbers 2010; Johnson et al. 2005; Liebig et al. 2005; Franzluebbers and Follett 2005; West and Post 2002; Lal 1999). However, most of the documented SOC sequestration rates have been determined using the “paired comparison method,” which refers to the comparison of two tillage systems to each other with the absence of the pretreatment baseline for SOC stocks measured prior to the implementation of such tillage treatments. This article critically reviews the paired comparison approach that has been used by many scientists in determining soil C sequestration rates. Paired tillage treatments, with one treatment such as moldboard plow (MP) or any CT selected as a baseline or control, have been used…