EGU21-9489, updated on 04 Mar 2021
https://doi.org/10.5194/egusphere-egu21-9489
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Indicators of soil functioning in conventional, conservation and organic agriculture

Monique Carnol1, Caroline Chartin2, Inken Krüger1,3, and Bas van Wesemael2
Monique Carnol et al.
  • 1University of Liège, InBioS - Plant and Microbial Ecology, Liège, Belgium (m.carnol@uliege.be)
  • 2Georges Lemaître Centre for Earth and Climate Research, Earth and Life Institute, Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
  • 3Current affiliation: Thünen Institute of Forest Ecosystems, Alfred-Möller-Straße 1, Haus 41/42 16225 Eberswalde, Germany

Sustainable management of agricultural systems is a major challenge for ensuring food security of the growing world population. Organic farming and reduced tillage are assumed to be sustainable agricultural practices improving soil quality relative to conventional management strategies. However, assessment of soil quality is often restrained to either physical, chemical or biological parameters. Soil organic carbon (SOC) is the most widely used indicator of soil quality, but it is not necessarily reactive to change, nor representative of the functioning of soil systems, in particular in relation to the realization of soil microbial processes, as it is composed of fractions with different availability for microbial activity and decomposition.

The objective of this study was to assess the influence of three major cropping systems: organic agriculture and conservation agriculture (no/reduced-tillage) vs. conventional agriculture on SOC fractions and microbial processes related to C and N cycling and to establish relationships between carbon fractions and microbial processes in order to identify the most relevant indicator of soil functioning. We hypothesized that 1) organic farming and conservation agriculture would improve soil functioning, 2) labile organic fractions would be better indicators of soil functioning.

We measured C and N in physical and chemical fractions (bulk, <20 µm, 20-2000µm, dissolved organic C, hot water extractable C, water soluble C, K2SO4 extractable C, microbial biomass C) and microbial processes (respiration potential, net N mineralization, metabolic diversity of soil bacteria) in 16 cropland sites in Wallonia, south Belgium (CARBIOSOL project).

Preliminary data analyses indicate improved soil functioning in organic managed sites relative to sites under conventional and conservation management and reveal hot water extractable carbon as a promising proxy for monitoring changes in soil functioning in response to agricultural practices. Final detailed data analyses will be presented.

How to cite: Carnol, M., Chartin, C., Krüger, I., and van Wesemael, B.: Indicators of soil functioning in conventional, conservation and organic agriculture, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9489, https://doi.org/10.5194/egusphere-egu21-9489, 2021.

Corresponding presentation materials formerly uploaded have been withdrawn.