Developing a Soil Sampling Protocol for the Oklahoma Carbon Program

Abstract

Developing strategies to reduce carbon emission and/or sequester carbon at minimum cost is critical to the goal of mitigating climate change. The Kyoto protocol has opened doors for carbon markets to trade carbon emissions reductions and sequestration, though carbon markets came into existence a few years before the Kyoto protocol was ratified. Several schemes are emerging around the world to promote carbon markets. Oklahoma carbon program is one such initiative designed to establish carbon markets in Oklahoma. Currently, the program is focusing on carbon sequestration through conservation practices on agricultural soils. Agricultural soils can act as potential sinks for atmospheric carbon, but high spatial variation makes it difficult to monitor organic carbon mass (OCM) sequestered in the soil. Thus, methodologies are required to monitor change in OCM precisely. The present study focuses on three studies conducted in order to develop a soil sampling protocol to monitor carbon credits raised by farmers in their fields under no-till or grassland management systems: 1) to select a probe feasible for soil sampling in terms of cost and handling, 2) to evaluate the fixed depth and fixed mass method to remove any difference in OCM as calculated using three different probes, 3) to determine organic carbon mass and variation in different textured soils and to evaluate the role of organic carbon concentration and bulk density in organic carbon mass as well as in variation.