Significant structural evolution of a long‐term fallow soil in response to agricultural management practices requires at least 10 years after conversion

Autor: John W. Crawford, Ian M. Clark, Sacha J. Mooney, Aurelie Bacq-Labreuil, Andrew L. Neal, Xiaoxian Zhang, Karl Ritz, Elsy Akkari
Rok vydání: 2020
Předmět:
Zdroj: European Journal of Soil Science. 72:829-841
ISSN: 1365-2389
1351-0754
DOI: 10.1111/ejss.13037
Popis: Agricultural practices can have significant effects on the physical and biological properties of soil. The aim of this study was to understand how the physical structure of a compromised soil, arising from long-term bare-fallow management, was modified by adopting different field management practices. We hypothesised that changing agricultural practice from bare-fallow to arable or grassland would influence the modification of pore structure via an increase in porosity, pore connectivity, and a more homogenous distribution of pore sizes; and that this change exerts a rapid development of soil structure following conversion. Soil aggregates (< 2 mm) collected in successive years from field plots subjected to three contrasting managements were studied; viz. bare-fallow, bare-fallow converted to arable, and bare-fallow converted to grassland. Soil structure was assessed by X-ray Computed Tomography on the aggregates at 1.5 µm resolution, capturing detail relevant to soil biophysical processes. The grassland system increased porosity, diversity of pore sizes, pore-connectivity and pore-surface density significantly over the decade following conversion. However, measured at this resolution, the development of most of these metrics of soil structure required approximately 10 years post-conversion to show a significant effect. The arable system did not influence soil structural development significantly. Only the pore size distribution was modified in grassland in a shorter time frame (2 years post-conversion). Hence development of the soil structural characteristics appears to require at least a decadal timescale following conversion to grassland.
Databáze: OpenAIRE
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