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Title: Mechanisms controlling soil carbon turnover and their potential application for enhancing carbon sequestration.

Abstract

No abstract prepared.

Authors:
; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
934644
Report Number(s):
ANL/BIO/JA-56538
Journal ID: ISSN 0165-0009; CLCHDX; TRN: US200814%%394
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Clim. Change; Journal Volume: 80; Journal Issue: 2007
Country of Publication:
United States
Language:
ENGLISH
Subject:
54 ENVIRONMENTAL SCIENCES; CARBON; CARBON SEQUESTRATION; SOILS

Citation Formats

Jastrow, J. D., Amonette, J. E., Bailey, V. L., and PNNL. Mechanisms controlling soil carbon turnover and their potential application for enhancing carbon sequestration.. United States: N. p., 2007. Web. doi:10.1007/s10584-006-9178-3.
Jastrow, J. D., Amonette, J. E., Bailey, V. L., & PNNL. Mechanisms controlling soil carbon turnover and their potential application for enhancing carbon sequestration.. United States. doi:10.1007/s10584-006-9178-3.
Jastrow, J. D., Amonette, J. E., Bailey, V. L., and PNNL. Mon . "Mechanisms controlling soil carbon turnover and their potential application for enhancing carbon sequestration.". United States. doi:10.1007/s10584-006-9178-3.
@article{osti_934644,
title = {Mechanisms controlling soil carbon turnover and their potential application for enhancing carbon sequestration.},
author = {Jastrow, J. D. and Amonette, J. E. and Bailey, V. L. and PNNL},
abstractNote = {No abstract prepared.},
doi = {10.1007/s10584-006-9178-3},
journal = {Clim. Change},
number = 2007,
volume = 80,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Two major mechanisms, (bio)chemical alteration and physicochemical protection, stabilize soil organic carbon (SOC) and thereby control soil carbon turnover. With (bio)chemical alteration, SOC is transformed by biotic and abiotic processes to chemical forms that are more resistant to decomposition and, in some cases, more easily retained by sorption to soil solids. With physicochemical protection, biochemical attack of SOC is inhibited by organomineral interactions at molecular to millimeter scales. Stabilization of otherwise decomposable SOM can occur via sorption to soil surfaces, complexation with soil minerals, occlusion within aggregates, and deposition in pores inaccessible to decomposers and extracellular enzymes. Soil structure (i.e.,more » the arrangement of solids and pores in the soil) is a master integrating variable that both controls and indicates the SOC stabilization status of a soil. To enhance SOC sequestration, the best option is to modify the soil physicochemical environment to favor the activities of fungi. Specific practices that accomplish this include minimizing tillage, maintaining a near-neutral soil pH and an adequate base cation exchange capacity (particularly Ca), ensuring adequate drainage, and minimizing erosion by water and wind. In some soils, amendments with various high-specific-surface micro- and mesoporous sorbents such as fly ash or charcoal can be beneficial.« less
  • Estimates of forest net primary production (NPP) demand accurate estimates of root production and turnover. We assessed root turnover with the use of an isotope tracer in two forest free-air carbon dioxide enrichment experiments. Growth at elevated carbon dioxide did not accelerate root turnover in either the pine or the hardwood forest. Turnover of fine root carbon varied from 1.2 to 9 years, depending on root diameter and dominant tree species. These long turnover times suggest that root production and turnover in forests have been overestimated and that sequestration of anthropogenic atmospheric carbon in forest soils may be lower thanmore » currently estimated.« less
  • Increased atmospheric nitrogen (N) deposition can alter the processing and storage of organic carbon in soils. In 2000, we began studying the effects of simulated atmospheric N deposition on soil carbon dynamics in three types of northern temperate forest that occur across a wide geographic range in the Upper Great Lakes region. These ecosystems range from 100% oak in the overstory (black oak-white oak ecosystem; BOWO) to 0% overstory oak (sugar maple-basswood; SMBW) and include the sugar maple-red oak ecosystem (SMRO) that has intermediate oak abundance. The leaf litter biochemistry of these ecosystems range from highly lignified litter (BOWO) tomore » litter of low lignin content (SMBW). We selected three replicate stands of each ecosystem type and established three plots in each stand. Each plot was randomly assigned one of three levels of N deposition (0, 30 & 80 kg N ha-1 y-1) imposed by adding NaNO3 in six equal increments applied over the growing season. Through experiments ranging from the molecular to the ecosystem scales, we produced a conceptual framework that describes the biogeochemistry of soil carbon storage in N-saturated ecosystems as the product of interactions between the composition of plant litter, the composition of the soil microbial community and the expression of extracellular enzyme activities. A key finding is that atmospheric N deposition can increase or decrease the soil C storage by modifying the expression of extracellular enzymes by soil microbial communities. The critical interactions within this conceptual framework have been incorporated into a new class of simulations called guild decomposition models.« less
  • The Huang-Hai Plain in northeast China has been cultivated for thousands of years and is the most productive wheat growing region in the country. Its agricultural future will be determined in large part by how global climatic changes affect regional conditions and by the actions China takes to mitigate or adapt to climate change impacts. One potential mitigation strategy is to promote soil carbon (C) sequestration, which would improve soil quality while simultaneously contributing to the mitigation of climate change. The IPCC estimates that 40 Pg of C could be sequestered in cropland soils worldwide over the next century. Heremore » we assess the potential for soil C sequestration with conversion of a conventional till (CT) continuous wheat system to a wheat-corn double cropping system and by implementing no till (NT) management for both continuous wheat and wheat-corn systems. To assess the influence of these management changes under a changing climate, we use two climate change scenarios at two time periods in the EPIC agro-ecosystem simulation model. The applied climate change scenarios are from the HadCM3 Global Climate Model for the time periods 2015-2045 and 2070-2099. The HadCM3 model projects that both temperature and precipitation will increase throughout the next century with increases of greater than 5 °C and up to 300 mm possible by 2099. An increase in the variability of temperature is also projected and is, accordingly, applied in the simulations. The EPIC model indicates that winter wheat yields would increase on average by 0.2 Mg ha-1 in the 2030 period and by 0.8 Mg ha-1 in the 2085 period due largely to the warmer nighttime temperatures and higher precipitation projected by the HadCM3 model. Simulated yields were not significantly affected by imposed changes in crop management. Simulated soil organic C content was higher under both NT management and double cropping than under CT continuous wheat. Soil C sequestration rates for continuous wheat systems were increased by 0.5 Mg ha-1 yr-1 by NT in the 2030 period and by 0.4 Mg ha-1 yr-1 in the 2085 period. With wheat-corn double cropping, NT increased sequestration rates by 1.3 and 1.0 Mg ha-1 yr-1 in 2030 and 2085, respectively. The total C offset due to a shift to NT management over 16 million hectares of agricultural land on the Huang-Hai Plain is 240 to 180 Tg C for continuous wheat management in 2030 and 2085, respectively and 675 to 495 Tg C for wheat-corn double cropping in 2030 and 2085, respectively.« less
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