Changes in soil organic carbon under perennial crops
Abstract
This study evaluates the dynamics of soil organic carbon (SOC) under perennial crops across the globe. It quantifies the effect of change from annual to perennial crops and the subsequent temporal changes in SOC stocks during the perennial crop cycle. It also presents an empirical model to estimate changes in the SOC content under crops as a function of time, land use, and site characteristics. We used a harmonized global dataset containing paired￢ﾀﾐcomparison empirical values of SOC and different types of perennial crops (perennial grasses, palms, and woody plants) with different end uses: bioenergy, food, other bio￢ﾀﾐproducts, and short rotation coppice. Salient outcomes include: a 20￢ﾀﾐyear period encompassing a change from annual to perennial crops led to an average 20% increase in SOC at 0￢ﾀﾓ30ￂﾠcm (6.0ￂﾠￂﾱￂﾠ4.6ￂﾠMg/ha gain) and a total 10% increase over the 0￢ﾀﾓ100ￂﾠcm soil profile (5.7ￂﾠￂﾱￂﾠ10.9ￂﾠMg/ha). A change from natural pasture to perennial crop decreased SOC stocks by 1% over 0￢ﾀﾓ30ￂﾠcm (￢ﾈﾒ2.5ￂﾠￂﾱￂﾠ4.2ￂﾠMg/ha) and 10% over 0￢ﾀﾓ100ￂﾠcm (￢ﾈﾒ13.6ￂﾠￂﾱￂﾠ8.9ￂﾠMg/ha). The effect of a land use change from forest to perennial crops did not show significant impacts, probably due to the limited number of plots; but the data indicated that while a 2% increase in SOC was observed at 0￢ﾀﾓ30ￂﾠcm (16.81ￂﾠￂﾱￂﾠ55.1ￂﾠMg/ha), a decrease in 24% was observed at 30￢ﾀﾓ100ￂﾠcm (￢ﾈﾒ40.1ￂﾠￂﾱￂﾠ16.8ￂﾠMg/ha). Perennial crops generally accumulate SOC through time, especially woody crops; and temperature was the main driver explaining differences in SOC dynamics, followed by crop age, soil bulk density, clay content, and depth. We present empirical evidence showing that the FAO perennialization strategy is reasonable, underscoring the role of perennial crops as a useful component of climate change mitigation strategies.
Created: 2020-05-15
Updated: 2026-03-13T17:26:29Z
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Language: Unknown