Herbal leys (multispecies swards) can potentially deliver greater agronomic and environmental benefits than conventional grass-clover swards in grazed agroecosystems. However, despite their popularity in agri-environment schemes, little is known about the effect of herbal leys on soil physical (e.g., porosity), chemical (e.g., carbon), and biological (e.g., soil fauna) characteristics. In the UK, a 2-ha replicated-field experiment utilising a herbal or grass-clover ley ( = 3 per sward) aimed to investigate the effect of sward type on soil quality. Each sward was rotationally grazed by weaned lambs (3.2 LU ha) over two grazing seasons, with soil physiochemical and biological characteristics assessed after 2-years using techniques such as X-ray micro-Computed Tomography (µCT) and microbial shallow shotgun sequencing. Soil chemical characteristics (e.g., pH) were unaffected by sward type. Similarly, topsoil (0–10 cm) organic carbon stocks measured after 2-years did not differ between the herbal (26.1 ± 1.1 t C ha) and grass-clover ley (25.7 ± 1.1 t C ha). X-ray µCT analysis revealed greater pore connectivity (Euler number) in grass-clover ley intact soil cores (0–10 cm depth, 7.5 cm width) than herbal ley cores dominated by ( = 0.008). However, there was no sward-type difference in aggregate stability or general pore characteristics, determined using X-ray µCT, in air-dried 4 mm aggregates obtained from 0–5 or 5–10 cm depth, nor did sward type affect earthworm abundance, microbial community composition or the functional gene profile. This study is the first to explore the effects of a commercial herbal ley on physical, chemical, and biological soil quality indicators in a rotationally grazed sheep pasture. While no improvements in soil quality indicators were observed after 2-years, these findings have significant implications for agri-environment schemes promoting herbal leys to achieve soil quality and sustainability, with further research needed to optimise the seed mixture and management regime to deliver greater long-term below-ground ecosystem service benefits.

中文翻译：

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两年后，与羊放牧草地中的草三叶草地相比，草本地对土壤孔隙度、蚯蚓丰度和微生物群落组成没有影响

在放牧农业生态系统中，草本草丛（多物种草丛）可能比传统草三叶草草丛带来更大的农艺和环境效益。然而，尽管它们在农业环境方案中很受欢迎，但人们对草药麦地对土壤物理（例如孔隙度）、化学（例如碳）和生物（例如土壤动物）特性的影响知之甚少。在英国，利用草药或草三叶草地（=每个草地 3 个）进行了 2 公顷的重复田间实验，旨在研究草地类型对土壤质量的影响。每个草地都由断奶羔羊（3.2 LU ha）在两个放牧季节轮流放牧，两年后使用 X 射线微计算机断层扫描 (μCT) 和微生物浅鸟枪测序等技术评估土壤理化和生物特征。土壤化学特性（例如pH）不受草地类型的影响。同样，两年后测量的表土（0-10 cm）有机碳储量在草本植物（26.1 ± 1.1 t C ha）和草三叶草（25.7 ± 1.1 t C ha）之间没有差异。X 射线 µCT 分析显示，草三叶草地完整土芯（0-10 厘米深，7.5 厘米宽）的孔隙连通性（欧拉数）大于草本地地芯（= 0.008）。然而，在从 0-5 或 5-10 cm 深度获得的风干 4 mm 聚集体中，使用 X 射线 μCT 测定，聚集体稳定性或一般孔隙特征不存在草丛类型差异，草丛类型也不影响蚯蚓丰度、微生物群落组成或功能基因谱。本研究首次探讨了商业草药对轮牧羊牧场物理、化学和生物土壤质量指标的影响。虽然两年后没有观察到土壤质量指标的改善，但这些发现对于促进草本地实现土壤质量和可持续性的农业环境计划具有重大意义，需要进一步研究来优化种子混合物和管理制度，以实现更长久的可持续发展。 - 长期地下生态系统服务效益。