Abstract
Developments in soil biology and in methods to characterize soil organic carbon can potentially deliver novel soil quality indicators that can help identify management practices able to sustain soil productivity and environmental resilience. This work aimed at synthesizing results regarding the suitability of a range of soil biological and biochemical properties as novel soil quality indicators for agricultural management. The soil properties, selected through a published literature review, comprised different labile organic carbon fractions [hydrophilic dissolved organic carbon, dissolved organic carbon, permanganate oxidizable carbon (POXC), hot water extractable carbon and particulate organic matter carbon], soil disease suppressiveness measured using a <i>Pythium</i>-<i>Lepidium</i> bioassay, nematode communities characterized by amplicon sequencing and qPCR, and microbial community level physiological profiling measured with MicroResp<sup>TM</sup>. Prior studies tested the sensitivity of each of the novel indicators to tillage and organic matter addition in ten European long-term field experiments (LTEs) and assessed their relationships with pre-existing soil quality indicators of soil functioning. Here, the results of these previous studies are brought together and interpreted relative to each other and to the broader body of literature on soil quality assessment. Reduced tillage increased carbon availability, disease suppressiveness, nematode richness and diversity, the stability and maturity of the food web, and microbial activity and functional diversity. Organic matter addition played a weaker role in enhancing soil quality, possibly due to the range of composition of the organic matter inputs used in the LTEs. POXC was the indicator that discriminated best between soil management practices, followed by nematode indices based on functional characteristics. Structural equation modeling shows that POXC has a central role in nutrient retention/supply, carbon sequestration, biodiversity conservation, erosion control and disease regulation/suppression. The novel indicators proposed here have great potential to improve existing soil quality assessment schemes. Their feasibility of application is discussed and needs for future research are outlined.
Highlights
Agricultural soils have traditionally been managed mainly for productivity because they underpin our existence through food, feed, fiber and timber production
Compared to the other indicators, permanganate oxidizable carbon (POXC), Hot water extractable carbon (HWEC), and particulate organic matter carbon (POMC)[27] were sensitive to both tillage and organic matter addition, while soil suppressiveness, free-living soil nematode communities and microbial catabolic profiles were more affected by tillage than by organic matter addition[28,29,30]
In agreement with the results presented in previous studies and with the hypothesis specified in the current work[27,28,29,30], POXC was found to have a multifunctional role in agricultural soils
Summary
Agricultural soils have traditionally been managed mainly for productivity because they underpin our existence through food, feed, fiber and timber production They have the potential to sustain a wide range of functions (or processes, a term used synonymously here) related to environmental resilience[1,2,3]. Intensive agricultural management has been highly successful in increasing production but often with detrimental effects on dynamic soil properties These impacts can in turn disrupt soil processes, soil multifunctionality, and soil-based ecosystem services[7,8,9,10] defined as the benefits for humankind derived from ecosystems[11]. The assessment and the monitoring of soil quality as affected by agricultural management is a pre-requisite of the fundamental redesign of agricultural systems[8,13,14] that aim to maintain or increase both agricultural productivity and environmental resilience through the adoption of alternative soil management practices
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
