# Developmental History of Soil Concepts from a Scientific Perspective
## 4 Discussion
### The Emergence of Soil Concepts
[PERSON] et al. (2016) posited that soil quality and soil health could be considered synonymous [55]. [PERSON] et al. (2018) suggested that the preferred term depends on the stakeholders (i.e., soil quality for researchers and soil health for farmers), although apparently there are no scientific surveys to validate this argument [56]. [PERSON] (2018) defined soil health as \"a holistic measure of a soil's productivity, resilience, and sustainability [6]\". The concept is straightforward in the abstract, yet challenging to define in practice from various viewpoints such as farmers, soil scientists, economists, and policymakers. Some prominent definitions of soil health and soil quality proposed over the past 20 years were summarized and compared by [PERSON] et al. (2018) [2]. For example, [PERSON] and [PERSON] (1997) defined it as the \"continued capacity of soil to function as a vital living system, within ecosystem and land-use boundaries, to sustain biological productivity; promote the quality of air and water environments; and maintain plant, animal, and human health [57]\". The U.S. Department of Agriculture--Natural Resources ConservationService (USDA-NRCS) simplified the definition of soil health in relation to soil quality as \"the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans\" [58]. [PERSON] et al. (2018) proposed measuring the dynamic variables that mainly fell within biological, environmental, and agronomic groups that are responsive to soil management, such as cover crop, based on a meta-analysis of 192 unique peer-reviewed papers [59]. These variables include soil respiration, soil aggregate stability, mineralizable nitrogen (N), soil erosion, infiltration, runoff, nutrient leaching, weed control, diseases, soil fauna, microbial indicators, soil N\({}_{2}\)O emissions, microbial biomass N, and other soil health indicators. These variables were measured for traditional soil surveys as indicators of soil quality. Instead, new aggregation methods of existing soil information into a comprehensive, sensible, and scientific-sounding index are the focal point of current discussions in the soil science community [5; 60]. Thus, soil health must be reconsidered similar to other soil concepts with the purpose of overcoming some limitations of past soil survey efforts, such as inconsistent soil measurement protocols. Under a large umbrella, the concepts of soil quality and soil health share the common goals of multiple stakeholders by targeting sustainable soil resource management under natural and anthropogenic pressures. The earliest publication on soil sustainability was found in a soil science journal in 1992; one year later, a soil resilience paper appeared. These concepts were the only ones found first in soil science journals (Tables 4 and 5). Considering that the two concepts appeared at almost the same time, they would likely share similar content, target, audiences, and semantic definitions, because they may be used interchangeably. However, [PERSON] (1992), the author of the first soil sustainability publication available in the Web of Science, claimed differently [61]. The author first defined soil sustainability as the \"susceptibility of soil to change under natural or anthropogenic perturbations,\" while soil resilience was defined as \"soil's ability to recover to the antecedent state following degradative perturbation or change in land use.\" Soil degradation would be the manifestation of a loss of soil sustainability and resilience. The author also argued that soil sustainability was characterized by three aspects, soil stability, soil resilience, and soil quality, all of which can be influenced by soil surface management (e.g., tillage) to a large degree. This view of soil stability and resilience seems to be consistent with other publications as well. For example, [PERSON] et al. (2018) argued that the stability and resilience of soil are produced by the complex interactions of functional soil attributes.