Carbon Stocks in Pampean Soils: A Simple Regression Model for Estimation of Carbon Storage Under Nondegraded Scenarios

Abstract

Using published data from a soil survey, a carbon (C) inventory of Pampean soils was performed. As a mean, carbon storage in the 0–20 cm soil layer is 40 t C/ha for the region, decreasing to about half in the 20–50 cm depth. In the 0–50 cm stratum stored, carbon is 3.3 109 t corresponding to a surveyed area of 57 Mha. By multiple‐regression analysis, an explanatory model of carbon content at different depths could be adjusted that accounts for 92% of variability of carbon levels in nondegraded soils. Climate, texture, and depth were the independent variables included in the model. When comparing carbon stored in the 0–20 cm layer of degraded soils belonging to the Rolling Pampa, an area subjected to cultivation since the nineteenth century, predicted carbon by the model averaged 60 t C/ha, and observed carbon content rounded 40 t C/ha. So this area lost around one‐third of the stored carbon in the upper soil layer by cropping. A similar estimation of carbon losses may be performed by other methodologies. Regression appeared to be a suitable tool for predicting soil degradation and carbon sequestration potential.