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.

中文翻译：

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响应农业管理实践的长期休耕土壤的显着结构演变需要在骨料水平转化后至少 10 年

农业实践会对土壤的物理和生物特性产生重大影响。本研究的目的是了解如何通过采用不同的田间管理实践来改变长期裸休管理造成的受损土壤的物理结构。我们假设将农业实践从裸休耕地改为耕地或草地将通过增加孔隙率、孔隙连通性和更均匀的孔径分布来影响孔隙结构的改变；并且这种变化使转化后土壤结构迅速发展。研究了连续几年从经过三种对比管理的田间地块收集的土壤团聚体（< 2 毫米）；即。荒地、荒地转为耕地、荒地转为草地。土壤结构通过 X 射线计算机断层扫描以 1.5 µm 的分辨率对聚集体进行评估，捕捉与土壤生物物理过程相关的细节。在转化后的十年中，草地系统显着增加了孔隙度、孔径的多样性、孔隙连通性和孔隙表面密度。然而，在此分辨率下测量，大多数土壤结构指标的开发需要在转换后大约 10 年才能显示出显着效果。耕作制度对土壤结构发展没有显着影响。在较短的时间范围内（转化后 2 年），草原中仅改变了孔径分布。因此，在转变为草地之后，土壤结构特征的发展似乎需要至少一个十年的时间尺度。