Soil quality (SQ) is the ability of soil to provide ecosystem functions and services. Implementation of a certain agricultural system can affect SQ and therefore play an essential role in achieving sustainable agriculture. The aim of this study was to explore how agricultural systems (conventional vs. organic), grazing regime (non-grazed vs. grazed) and the different proportions of temporary grass-clover leys in crop rotations (ley time proportion, LTP) affect SQ within a mixed (cropping and pasture/dairy system) commercial farming enterprise in the UK. Seven SQ indicators were evaluated, including chemical (pH; available phosphorus (P); potassium (K)), physical (bulk density, BD; aggregate stability, AS) and biological (total carbon (C); microbial biomass carbon, MBC) sectors. All SQ indicators were measured at three depth intervals (0–0.15, 0.15–0.30, 0.30–0.60 m), except for AS and MBC, which were only considered for the topsoil (0–0.15 m). The findings reflected existing knowledge on the advantages of organic vs. conventional systems for SQ indicators, with the former showing higher MBC and similar K, BD, AS and C in the 0–0.30-m compared to the latter. Lower topsoil available P in organic systems can be related to the lack of measurements in all P pools. When grazing was included: (a) both agricultural systems showed higher topsoil available P, C and MBC; and (b) there was a higher topsoil K in organic systems, whereas it positively affected topsoil BD and C (0.15–0.30 m) in conventional systems. Increasing LTP to 30–40% of the full crop rotation increased topsoil AS and C (0–0.30 m) in a linear fashion. Subsoil conditions (>0.30 m) favoured K, BD and C in conventional systems, but these results should be considered carefully. It was concluded that both organic and conventional systems delivered similar levels of SQ and that reviving mixed farming systems may be a key factor for delivering multifunctional agroecosystems that maintain SQ and optimize ecosystem services.

中文翻译：

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在传统和有机农业系统下，轮作中放牧的临时禾本科草可以对土壤质量产生积极影响

土壤质量（SQ）是土壤提供生态系统功能和服务的能力。某种农业系统的实施会影响 SQ，因此在实现可持续农业方面发挥着重要作用。本研究的目的是探讨农业系统（传统与有机）、放牧制度（非放牧与放牧）以及轮作中临时草丛的不同比例（草叶时间比例，LTP）如何影响 SQ在英国的一家混合（种植和牧场/乳制品系统）商业农业企业中。评估了七个 SQ 指标，包括化学（pH；有效磷（P）；钾（K））、物理（堆积密度，BD；聚集稳定性，AS）和生物（总碳（C）；微生物生物量碳，MBC）部门。所有 SQ 指标均在三个深度间隔 (0–0.15, 0. 15–0.30, 0.30–0.60 m)，除了 AS 和 MBC，它们只考虑表土 (0–0.15 m)。研究结果反映了现有的关于有机与传统系统在 SQ 指标上的优势的知识，与后者相比，前者在 0-0.30 米中显示出更高的 MBC 和相似的 K、BD、AS 和 C。有机系统中较低的表土有效磷可能与所有磷池中缺乏测量有关。当包括放牧时： (a) 两种农业系统都显示出较高的表土有效磷、碳和 MBC；(b) 有机系统中表土 K 较高，而它对常规系统中表土 BD 和 C (0.15-0.30 m) 产生积极影响。将 LTP 增加到整个轮作的 30-40%，以线性方式增加了表土 AS 和 C (0-0.30 m)。底土条件 (>0.30 m) 有利于传统系统中的 K、BD 和 C，但应仔细考虑这些结果。得出的结论是，有机系统和传统系统都提供了相似的 SQ 水平，恢复混合农业系统可能是提供保持 SQ 和优化生态系统服务的多功能农业生态系统的关键因素。