TY - JOUR
T1 - Impact of bare fallow management on soil carbon storage and aggregates across a rock fragment gradient
AU - Schweizer, Steffen A.
AU - Aehnelt, Michaela
AU - Bucka, Franziska
AU - Totsche, Kai Uwe
AU - Kögel-Knabner, Ingrid
N1 - Publisher Copyright:
© 2024 The Authors. Journal of Plant Nutrition and Soil Science published by Wiley-VCH GmbH.
PY - 2024/2
Y1 - 2024/2
N2 - Background: Our understanding of C storage in soils lacks insights investigating organic matter (OM) depletion, often studied in bare fallow systems. The content of coarse rock fragments is often excluded, whereas it may affect C storage. Aims: We aim to contribute to a better understanding of the impact of bare fallow on C storage mechanisms in the soil as influenced by its coarse rock fragment contents. We investigated whether bare fallow induced a depletion of C in OM fractions and analyzed to which extent this affected soil aggregate size distribution and the C loading of the clay-sized fraction. Methods: A comparison of 14 years bare fallow management with adjacent cropped soils located in Selhausen (Germany) provided a gradient of coarse rock fragments of 34%–71%, from which sites with three different fine earth (FE) contents were compared. Across the FE gradient, we isolated particulate OM and mineral-associated OM fractions, obtained microaggregate and macroaggregate size fractions, and quantified the C loading. Results: Bare fallow management induced an OM depletion at lower contents of FE. There, the management influence was more concentrated onto less FE volume. The contribution of both particulate and mineral-associated OM fractions to the C in the low-FE soils decreased. The C loading increased under bare fallow, compared to cropped soil. In the low-FE soil, we also found less macroaggregates, whereas the C content decreased in some microaggregate size fractions. Conclusions: A high content of coarse rock fragments can enhance OM depletion decreasing mineral-associated and particulate C under bare fallow.
AB - Background: Our understanding of C storage in soils lacks insights investigating organic matter (OM) depletion, often studied in bare fallow systems. The content of coarse rock fragments is often excluded, whereas it may affect C storage. Aims: We aim to contribute to a better understanding of the impact of bare fallow on C storage mechanisms in the soil as influenced by its coarse rock fragment contents. We investigated whether bare fallow induced a depletion of C in OM fractions and analyzed to which extent this affected soil aggregate size distribution and the C loading of the clay-sized fraction. Methods: A comparison of 14 years bare fallow management with adjacent cropped soils located in Selhausen (Germany) provided a gradient of coarse rock fragments of 34%–71%, from which sites with three different fine earth (FE) contents were compared. Across the FE gradient, we isolated particulate OM and mineral-associated OM fractions, obtained microaggregate and macroaggregate size fractions, and quantified the C loading. Results: Bare fallow management induced an OM depletion at lower contents of FE. There, the management influence was more concentrated onto less FE volume. The contribution of both particulate and mineral-associated OM fractions to the C in the low-FE soils decreased. The C loading increased under bare fallow, compared to cropped soil. In the low-FE soil, we also found less macroaggregates, whereas the C content decreased in some microaggregate size fractions. Conclusions: A high content of coarse rock fragments can enhance OM depletion decreasing mineral-associated and particulate C under bare fallow.
KW - C loading
KW - organic matter depletion
KW - particulate and mineral-associated organic carbon
KW - soil microaggregates
UR - http://www.scopus.com/inward/record.url?scp=85170697925&partnerID=8YFLogxK
U2 - 10.1002/jpln.202300156
DO - 10.1002/jpln.202300156
M3 - Article
AN - SCOPUS:85170697925
SN - 1436-8730
VL - 187
SP - 118
EP - 129
JO - Journal of Plant Nutrition and Soil Science
JF - Journal of Plant Nutrition and Soil Science
IS - 1
ER -