Objective The objective of this study was to investigate the differences in the response of soil properties and crop growth to soil compaction by agricultural machinery across China.

Method The study conducted an extensive meta-analysis, integrating data from 687 field measurements of soil compaction, sourced from 20 peer-reviewed articles. The dataset, which encompassed a range of variables, including soil compaction, crop yield, plant height, root length, and both above- and below-ground biomass, was subjected to a systematic categorization process. This process was conducted across a variety of factors, such as geographical research sites, soil depths, levels of soil compaction, and crop types. Subsequently, the effect of machinery-induced soil compaction on each indicator was calculated to quantitatively synthesize its effects on soil ecosystem services and crop growth.

Result The results showed that the use of agricultural machinery resulted in a significant 34.8% increase in soil compaction (P < 0.05), with this effect exhibiting a positive correlation with the compaction level. Specifically, soil compaction exhibited a significant increase of 24.0%, 33.6% and 52.2% under light, medium and heavy compaction conditions, respectively (P < 0.05). The mechanical compaction procedure significantly amplified soil compaction within the 0-30 cm soil layer (P < 0.05), with increases of 81.5%, 34.6% and 20.8% in the 0-10 cm, 10-20 cm and 20-30 cm soil layers, respectively. Furthermore, soil compaction was found to impede crop growth, as evidenced by a statistically significant 19.0% reduction in root length (P < 0.05). It was noteworthy that mechanical compaction resulted in a 4.1% increase in above-ground biomass over the range of data collected in this study. Under heavy compaction conditions, the yield was significantly diminished by 12.3% (P < 0.05). In addition, the study revealed regional disparities in the response of soil characteristics and crop growth to mechanical compaction across diverse agricultural regions of China. Apart from the Yunnan-Guizhou plateau, our findings illustrated that farm machines led to a significant increase in soil compaction by 34.5%, 26.1% and 31.6% in the Northeast China plain, the Huang-Huai-Hai plain, and the Middle-lower Yangtze plain, respectively (P < 0.05).

Conclusion Mechanical compaction exerted a significant influence on soil compaction and crop growth dynamics, with its impact intensifying in direct proportion to increasing compaction levels and diminishing with greater soil depth. Notably, excessive mechanical compaction posed a substantial hindrance to crop growth, manifesting in reduced root lengths and diminished crop yields. A multitude of factors, ranging from soil texture and precipitation patterns to crop types and the usage habits of agricultural machinery, collectively shaped the response of soil characteristics and crop growth to mechanical compaction across China's different agricultural zones. This suggested the necessity for region-specific agricultural management strategies that were finely adapted to the distinctive conditions and sensitivities of each zone. By implementing targeted strategies, it was possible to enhance the resilience and productivity of agricultural landscapes in the context of soil compaction challenges.