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Fire effects on the persistence of soil organic matter and long-term carbon storage

Adam F. A. Pellegrini, Jennifer Harden, Katerina Georgiou, Kyle S. Hemes, Avni Malhotra, Connor J. Nolan & Robert B. Jackson Abstract One paradigm in biogeochemistry is that frequent disturbance tends to deplete carbon (C) in soil organic matter (SOM) by reducing biomass inputs and promoting losses. However, disturbance by fire has challenged this paradigm because soil C responses to frequent and/or intense fires are highly variable, despite observed declines in biomass inputs. Here, we review recent advances to illustrate that fire-driven changes in decomposition, mediated by altered SOM stability, are an important compensatory process ...

Exploring cross-national public support for the use of enhanced weathering as a land-based carbon dioxide removal strategy

Elspeth Spence, Emily Cox & Nick Pidgeon Abstract This study explores how public attitudes across three countries influence support towards terrestrial enhanced weathering, whereby silicate minerals are applied to agricultural land to remove carbon dioxide from the atmosphere. An online survey was administered in Australia (N = 1000), the UK (N = 1000), and the USA (N = 1026) where there are ongoing field trials of this technique. Findings are similar across all three countries with many participants unfamiliar with enhanced weathering and unsure about supporting the use of enhanced weathering. Results show that positive affect is the main ...

Enhancing natural cycles in agro-ecosystems to boost plant carbon capture and soil storage

Wolfram Buss, Kirsty Yeates, Eelco J Rohling, Justin Borevitz Abstract One of society’s greatest challenges is sequestering vast amounts of carbon to avoid dangerous climate change without driving competition for land and resources. Here we assess the potential of an integrated approach based on enhancement of natural biogeochemical cycles in agro-ecosystems that stimulate carbon capture and storage while increasing resilience and long-term productivity. The method integrates plant photosynthesis in the form of (cover) crops and agroforestry, which drives carbon capture. Belowground plant-carbon is efficiently stored as stable soil organic ...

Direct measurement of CO2 drawdown in mine wastes and rock powders: Implications for enhanced rock weathering

Amanda R.Stubbs, Carlos Paulo, Ian M.Power, Baolin Wang, Nina Zeyen, Siobhan A.Wilson Abstract Enhanced rock weathering (ERW) sequesters CO2 via solubility and mineral trapping and can be implemented by the mining industry to reduce their net greenhouse gas emissions. Kimberlite residues from Venetia Diamond Mine in South Africa, as well as powdered forsterite, serpentinite, wollastonite skarn, and 10 wt.% brucite mixed with quartz sand, were tested as potential feedstocks for ERW. A CO2 flux system directly measured CO2 removal rates and sensors tracked laboratory conditions and pore water saturation during a series of 2-week experiments. With ...

Could crushed rocks absorb enough carbon to curb global warming?

Peter Yeung A little-examined form of geoengineering takes what rocks normally do—lock up carbon—and spreads it through the oceans. Download

Bedrock Weathering Controls on Terrestrial Carbon-Nitrogen-Climate Interactions

Pawlok Dass, Benjamin Z. Houlton, Yingping Wang, David Wårlind, Scott Morford Abstract Anthropogenic nitrogen deposition is widely considered to increase CO2 sequestration by land plants on a global scale. Here, we demonstrate that bedrock nitrogen weathering contributes significantly more to nitrogen-carbon interactions than anthropogenic nitrogen deposition. This working hypothesis is based on the introduction of empirical results into a global biogeochemical simulation model over the time period of the mid-1800s to the end of the 21st century. Our findings suggest that rock nitrogen inputs have contributed roughly 2–11 times more to plant ...

Global Beiogeochemical Cycles

Anthropogenic nitrogen deposition is widely considered to increase CO2 sequestration by land plants on a global scale. Here, we demonstrate that bedrock nitrogen weathering contributes significantly more to nitrogen-carbon interactions than anthropogenic nitrogen deposition. This working hypothesis is based on the introduction of empirical results into a global biogeochemical simulation model over the time period of the mid-1800s to the end of the 21st century. Our findings suggest that rock nitrogen inputs have contributed roughly 2–11 times more to plant CO2 capture than nitrogen deposition inputs since pre-industrial times. Climate change ...

Remineralizing soils? The agricultural usage of silicate rock powders: A review

Philipp Swoboda Thomas F.Döring Martin Hamer Abstract Soil nutrient depletion threatens global food security and has been seriously underestimated for potassium (K) and several micronutrients. This is particularly the case for highly weathered soils in tropical countries, where classical soluble fertilizers are often not affordable or not accessible. One way to replenish macro- and micronutrients are ground silicate rock powders (SRPs). Rock forming silicate minerals contain most nutrients essential for higher plants, yet slow and inconsistent weathering rates have restricted their use in the past. Recent findings, however, challenge past ...

Testing the ability of plants to access potassium from framework silicate minerals

David A C Manning, Joana Baptista, Mallely Sanchez Limon, Kirsten Brandt Abstract The availability of K, essential for plant growth, from syenite (a silicate rock in which potassium feldspar is the dominant mineral; N 90 wt%), and phlogopite mica has been demonstrated using carefully designed plant growth pot experiments in which the only added source of K was the mineral of interest, with no loss of nutrients through drainage. Using pure quartz sand as a soil, both growth (increase in diameter) of leek plants and K-content of the plant material showed a dose-dependent positive response to the application (114–43000 mg K/pot) of milled ...

Enhanced weathering strategies for stabilizing climate and averting ocean acidification

Lyla L. Taylor, Joe Quirk, Rachel M. S. Thorley, Pushker A. Kharecha, James Hansen, Andy Ridgwell, Mark R. Lomas, Steve A. Banwart & David J. Beerling Abstract Chemical breakdown of rocks, weathering, is an important but very slow part of the carbon cycle that ultimately leads to CO2 being locked up in carbonates on the ocean floor. Artificial acceleration of this carbon sink via distribution of pulverized silicate rocks across terrestrial landscapes may help offset anthropogenic CO2 emissions . We show that idealized enhanced weathering scenarios over less than a third of tropical land could cause significant drawdown of atmospheric CO2 ...