Natural and managed soil structure: On the fragile scaffolding for soil functioning

Abstract

Soil structure in natural systems is a product of complex interactions between biological activity, climate and soil minerals that promote aggregation and accumulation of biopores. In arable lands, the management of soil structure often requires the mechanical fragmentation of hardened soil to improve seedbed, control weeds and bury plant residue. Despite difficulties in defining and quantifying soil structure, its critical role is evidenced by loss of productivity when natural structure is perturbed (e.g. compaction) and the long history of tillage in agriculture. To overcome persistent ambiguities among scientific disciplines regarding definition and function of soil structure, we propose a framework for distinguishing managed and natural soil structure based on their different formation processes and functions. Natural soil structure preserves ecological order and legacy that promotes biopore reuse, stabilizes foodwebs and protects soil organic carbon (SOC). The contribution of net primary productivity of natural lands to soil structure forming processes makes it a useful (surrogate) metric of soil structure. The benefits of managed soil structure for crops are quantified indirectly via comparisons with no-till farming under similar conditions. The levels and trends of SOC are useful metrics for the status of natural and managed soil structure. The systematic consideration of soil structure state in natural and arable lands using suitable metrics is a prerequisite for rational decisions related to land management and ensuring sustainable functioning of a fragile and central resource such as soil.

Keywords

Soil structure; Soil organic carbon; Tillage; No-till; Soil aggregates; Land use

Published in

Soil and Tillage Research
2021, volume: 208, article number: 104912

SLU Authors

• Keller, Thomas

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    
  • Agroscope

Associated SLU-program

SLU Plant Protection Network

Global goals (SDG)

SDG12 Responsible consumption and production
SDG15 Life on land

UKÄ Subject classification

Soil Science

Publication identifier

• DOI: https://doi.org/10.1016/j.still.2020.104912

Permanent link to this page (URI)

https://res.slu.se/id/publ/111327