Segura Carmen, Horrocks Claire, Lopez-Aizpun Maria, Blackwell Martin S A, Darch Tegan, Hood Jess, Le Cocq Kate, McAuliffe Graham A, Lee Michael R F, Cardenas Laura
Rothamsted Research, North Wyke, Okehampton, Devon, EX20 2SB, UK.
Rothamsted Research, North Wyke, Okehampton, Devon, EX20 2SB, UK.
J Environ Manage. 2023 Mar 15;330:117096. doi: 10.1016/j.jenvman.2022.117096. Epub 2023 Jan 4.
Healthy soils are key to sustainability and food security. In temperate grasslands, not many studies have focused on soil health comparisons between contrasting pasture systems under different management strategies and treatment applications (e.g. manures and inorganic fertilisers). The aim of this study was to assess the responses of soil health indicators to dung, urine and inorganic N fertiliser in three temperate swards: permanent pasture not ploughed for at least 20 years (PP), high sugar ryegrass with white clover targeted at 30% coverage reseeded in 2013 (WC), and high sugar ryegrass reseeded in 2014 (HG). This study was conducted on the North Wyke Farm Platform (UK) from April 2017 to October 2017. Soil health indicators including soil organic carbon (SOC, measured by loss of ignition and elemental analyser), dissolved organic carbon (DOC), total nitrogen (TN), C:N ratio, soil C and N bulk isotopes, pH, bulk density (BD), aggregate stability, ergosterol concentration (as a proxy for fungi biomass), and earthworms (abundance, mass and density) were measured and analysed before and after application of dung and N fertilizer, urine and N fertiliser, and only N fertiliser. The highest SOC, TN, DOC, ergosterol concentration and earthworms as well as the lowest BD were found in PP, likely due to the lack of ploughing. Differences among treatments were observed due to the application of dung, resulting in an improvement in chemical indicators of soil health after 50 days of its application. Ergosterol concentration was significantly higher before treatment applications than at the end of the experiment. No changes were detected in BD and aggregate stability after treatment applications. We conclude that not enough time had passed for the soil to recover after the ploughing and reseeding of the permanent pasture, independently of the sward composition (HG or WC). Our results highlight the strong influence of the soil management legacy in temperate pasture and the positive effects of dung application on soil health over the short term. In addition, we point out the relevance of using standardised methods to report soil health indicators and some methodological limitations.
健康的土壤是可持续发展和粮食安全的关键。在温带草原地区，针对不同管理策略和处理方式（如粪肥和无机肥料）下对比牧场系统之间的土壤健康比较，相关研究并不多。本研究的目的是评估三种温带草皮中土壤健康指标对粪便、尿液和无机氮肥的响应：至少20年未翻耕的永久牧场（PP）、2013年重新播种的目标是白三叶草覆盖率达30%的高糖黑麦草（WC），以及2014年重新播种的高糖黑麦草（HG）。本研究于2017年4月至2017年10月在英国北怀克农场平台开展。土壤健康指标包括土壤有机碳（SOC，通过灼烧失重法和元素分析仪测量）、溶解有机碳（DOC）、总氮（TN）、碳氮比、土壤碳和氮的整体同位素、pH值、容重（BD）、团聚体稳定性、麦角固醇浓度（作为真菌生物量的替代指标）以及蚯蚓（数量、质量和密度），在施用粪便和氮肥、尿液和氮肥以及仅施用氮肥前后进行了测量和分析。PP中发现了最高的SOC、TN、DOC、麦角固醇浓度和蚯蚓数量以及最低的BD，这可能是由于缺乏翻耕。由于粪便的施用，各处理之间存在差异，导致施用50天后土壤健康的化学指标有所改善。处理施用前的麦角固醇浓度显著高于实验结束时。处理施用后，BD和团聚体稳定性未检测到变化。我们得出结论，无论草皮组成如何（HG或WC），永久牧场翻耕和重新播种后，土壤恢复所需的时间都不够。我们的结果凸显了温带牧场土壤管理遗留问题的强大影响以及短期内施用粪便对土壤健康的积极影响。此外，我们指出了使用标准化方法报告土壤健康指标的相关性以及一些方法上的局限性。
