Departamento de Ecología y Biología Animal, Universidad de Vigo, Vigo, Spain.
Centre for Ecology and Hydrology Lancaster, Bailrigg, Lancaster, UK.
Glob Chang Biol. 2017 Oct;23(10):4396-4419. doi: 10.1111/gcb.13744. Epub 2017 May 31.
The adoption of less intensive soil cultivation practices is expected to increase earthworm populations and their contributions to ecosystem functioning. However, conflicting results have been reported on the effects of tillage intensity on earthworm populations, attributed in narrative reviews to site-dependent differences in soil properties, climatic conditions and agronomic operations (e.g. fertilization, residue management and chemical crop protection). We present a quantitative review based on a global meta-analysis, using paired observations from 165 publications performed over 65 years (1950-2016) across 40 countries on five continents, to elucidate this long-standing unresolved issue. Results showed that disturbing the soil less (e.g. no-tillage and conservation agriculture [CA]) significantly increased earthworm abundance (mean increase of 137% and 127%, respectively) and biomass (196% and 101%, respectively) compared to when the soil is inverted by conventional ploughing. Earthworm population responses were more pronounced when the soil had been under reduced tillage (RT) for a long time (>10 years), in warm temperate zones with fine-textured soils, and in soils with higher clay contents (>35%) and low pH (<5.5). Furthermore, retaining organic harvest residues amplified this positive response to RT, whereas the use of the herbicide glyphosate did not significantly affect earthworm population responses to RT. Additional meta-analyses confirmed that epigeic and, more importantly, the bigger-sized anecic earthworms were the most sensitive ecological groups to conventional tillage. In particular, the deep burrower Lumbricus terrestris exhibited the strongest positive response to RT, increasing in abundance by 124% more than the overall mean of all 13 species analysed individually. The restoration of these two important ecological groups of earthworms and their burrowing, feeding and casting activities under various forms of RT will ensure the provision of ecosystem functions such as soil structure maintenance and nutrient cycling by "nature's plough."
采用较少强度的土壤耕作措施预计会增加蚯蚓的数量及其对生态系统功能的贡献。然而，关于耕作强度对蚯蚓种群的影响，有相互矛盾的结果报告，这些结果在叙述性评论中归因于土壤特性、气候条件和农业操作（例如施肥、残留物管理和化学作物保护）在不同地点的差异。我们提出了一个基于全球荟萃分析的定量综述，使用来自全球 40 个国家的 165 个出版物的配对观测数据，这些数据跨越了五个大陆，可追溯到 65 年（1950-2016 年），以阐明这个长期存在但尚未解决的问题。结果表明，与传统耕作相比，较少地扰动土壤（例如免耕和保护性农业）显著增加了蚯蚓的丰度（分别增加了 137%和 127%）和生物量（分别增加了 196%和 101%）。当土壤长期处于减少耕作（RT）状态时（>10 年），在温暖的温带地区和质地细腻的土壤中，以及在具有较高粘粒含量（>35%）和较低 pH 值（<5.5）的土壤中，蚯蚓种群的响应更为明显。此外，保留有机收获残留物放大了这种对 RT 的正向响应，而使用除草剂草甘膦则不会显著影响蚯蚓种群对 RT 的响应。其他荟萃分析证实，表栖型蚯蚓和更重要的大型穴居蚯蚓是对传统耕作最敏感的生态类群。特别是深穴居蚯蚓 Lumbricus terrestris 对 RT 的响应最强，其丰度增加了 124%，比单独分析的 13 种蚯蚓的平均水平高出 124%。在各种形式的 RT 下，这两个重要的蚯蚓生态类群及其掘洞、觅食和排泄活动的恢复将确保“自然犁”提供土壤结构维护和养分循环等生态系统功能。
