Herbal leys have no effect on soil porosity, earthworm abundance, and microbial community composition compared to a grass-clover ley in a sheep grazed grassland after 2-years
Herbal leys have no effect on soil porosity, earthworm abundance, and microbial community composition compared to a grass-clover ley in a sheep grazed grassland after 2-years
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DOI：
10.1016/j.agee.2024.108928
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发表时间：
2024-02-15
影响因子：
6.6
通讯作者：
Jones，Davey L.
中科院分区：
文献类型：
--
作者：
Cooledge，Emily C.;Sturrock，Craig J.;Jones，Davey L.
在放牧的农业生态系统中，草本牧草（多物种草地）比传统的草三叶草草地具有更大的农学和环境效益。然而，尽管它们在农业环境计划中很受欢迎，但人们对草本植物对土壤物理（如孔隙度）、化学（如碳）和生物（如土壤动物）特性的影响知之甚少。在英国，一个2公顷的复制现场实验，利用草药或草三叶草ley（n= 3每草地）的目的是调查草地类型对土壤质量的影响。每个草地在两个放牧季节由断奶羔羊（3.2 LU ha 1）轮流放牧，2年后使用X射线显微计算机断层扫描（µCT）和微生物浅层鸟枪测序等技术评估土壤理化和生物学特性。土壤化学特性（如pH值）不受草地类型。同样，2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 1）和草三叶草（25.7±1.1 t C ha 1）之间没有差异。X射线µCT分析显示，草-三叶草层完整土芯（0-10 cm深，7.5 cm宽）的孔隙连通性（欧拉数）大于以车前草为主的草本层芯（p= 0.008）。然而，在从0-5或5-10 cm深度获得的风干4 mm团聚体中，使用X射线µCT测定的团聚体稳定性或一般孔隙特征没有草地类型差异，草地类型也不影响微生物丰度，微生物群落组成或功能基因谱。本研究首次探讨了在轮牧绵羊牧场中，商业草本层对土壤物理、化学和生物质量指标的影响。虽然2年后没有观察到土壤质量指标的改善，但这些发现对促进草本植物获得土壤质量和可持续性的农业环境计划具有重要意义，需要进一步研究以优化种子混合和管理制度，以提供更大的长期地下生态系统服务效益。
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 agrienvironment schemes, little is known about the effect of herbal leys on soil physical (eg, porosity), chemical (eg, carbon), and biological (eg, soil fauna) characteristics. In the UK, a 2-ha replicated-field experiment utilising a herbal or grass-clover ley (n= 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 1) 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 (eg, 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 1) and grass-clover ley (25.7±1.1 t C ha 1). 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 Plantago lanceolata (p= 0.008). However, there was no swardtype 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.