Dear Yang Hu and Coauthors,
Thank you for your comprehensive review on soil health assessments and the role of proximal sensing. While the manuscript addresses an important topic and presents valuable concepts, several significant concerns must be addressed before acceptance for publication.

While both reviewers agreed that your manuscript presents an important topic, they both identified several issues that need to be addressed. For instance, both reviewers noted that the manuscript emphasized the disadvantages of laboratory methods and advantages of sensors, without addressing their limitations, costs, or implementation challenges. They consistently noted the lack of concrete evidence, case studies, and quantitative comparisons to support the theoretical claims, as well as a disconnect between the ecological framework and sensing technologies that undermines the paper's central thesis. Additionally, both reviewers called for more technical specificity, better integration of concepts, and honest assessment of the substantial practical barriers to operationalizing the proposed framework, including standardization needs, calibration requirements, and real-world adoption challenges. These common concerns highlight that the aspirational vision presented in the manuscript currently lacks balanced evaluation, concrete evidence, and practical grounding necessary to support its claims about the operational readiness of sensor-based soil health assessments.
A fundamental weakness of this manuscript lies in its failure to demonstrate how sensing technologies specifically enable and enhance the proposed ecological framework for soil health assessment. The ecological approach (Section 9) and sensing technologies (Sections 10-12) are presented as disconnected parallel concepts rather than integrated solutions, with no clear mechanistic connection showing why sensors are uniquely suited to operationalize ecological soil health assessment framework. The proposed ecological framework appears entirely method-agnostic, failing to demonstrate why a sensor-based measurement approach is superior to traditional laboratory methods, thus failing to support the central idea that proximal sensing is pivotal to this framework.
While the manuscript extensively evaluates the limitations of current lab-based soil health indicators and assessment approaches (Sections 5-9), it fails to establish clear causal links between these identified problems and how sensor-based measurements specifically resolve them. For instance, you identify issues with indicator selection subjectivity, interpretation challenges, and integration difficulties in current frameworks, but do not demonstrate how sensing technologies fundamentally address these conceptual and methodological problems rather than simply providing alternative measurement approaches. The manuscript contains numerous assertions about sensor benefits (rapid data collection, cost-effectiveness, spatial coverage) but lacks rigorous quantitative comparisons with conventional methods that would substantiate claims of superior performance for soil health assessment.
Proximal sensing technologies face significant limitations that impede their operational deployment for soil property predictions, including the lack of standardized protocols that make it difficult to compare and validate approaches across different studies and geographic settings. While finer spectral and spatial resolutions are often pursued, they do not necessarily improve prediction accuracy and can lead to overfitting, and the requirement for extensive site-specific calibrations limits model transferability and scalability.
The paper would be greatly improved by providing more discussion on the challenges and steps required to operationalize such a framework. For example, operationalizing many of these technologies would require the development of standardized hardware and software integration protocols (i.e., calibration transfer), validation frameworks for diverse soil-landscape conditions, cost-effective portable sensor systems, and methods to assess sensor interaction effects and compatibility across different measurement targets and sample supports. Additionally, sensor response consistency over time must be improved to minimize frequent recalibration needs, while extending capabilities beyond basic soil properties to dynamic biogeochemical indicators and integrative soil health indices that can better inform soil health assessments across varied soil systems. While significant process has been made over the past several decades, significantly more work is needed to implement your proposed framework.
Additionally, as noted by Reviewer 2, the ecologically-based soil health assessment framework is underdeveloped and not clearly connected to the lab vs sensor-based measurement discussion. While you discuss the benefits of evaluating soil functions vs human focused ecosystem services, it is not clear how you propose to quantify these functions from sensor measurements. Measuring soil processes and functions is incredibly complex and challenging and is the primary reason most soil health assessments focus on measuring soil properties and indicators. Integrative sensing offers a promising approach but requires a comprehensive sensor-based characterization of soil systems in different ecological states or conditions. In addition, you fail to adequately articulate why an ecological perspective on soil health inherently requires or benefits from sensor-based measurement approaches, leaving readers without a compelling rationale for the purported synergy between ecological frameworks and sensing technologies that forms the manuscript's core premise.
Both reviewers also suggested additional examples/case studies illustrating examples of sensor based soil health assessments and additional review of relevant sensor technologies and how they can support the proposed framework. While I agree with your response that there is already a wealth of literature reviews on the various subjects addressed in this review paper, none of them, to my knowledge, specifically address the application of soil sensor for soil health assessments. Therefore, you should consider providing more concrete examples of how these soil sensor technologies have been used (or could be used) to assess soil health, describing both the documented strengths as well as their weaknesses. While soil sensing technologies hold considerable potential for improving soil health assessment, considerable work is still needed to operationalize these technologies. Adding references to Fig 4 (possibly as supporting materials) would help guide readers to the relevant sensor-specific literature.

In summary, your manuscript requires major revisions, and should addressing the following points:
1. Provide a clearer and more practical description of the proposed soil health assessment framework that addresses specific protocols, implementation procedures, indicator selection criteria, threshold establishment methods, and validation approaches.
2. Present balanced technical comparisons that honestly discuss sensor limitations (costs, calibration requirements, standardization challenges) alongside advantages, while addressing laboratory method strengths as well as weaknesses,
3. Demonstrate mechanistic integration showing how sensing technologies specifically enable and enhance ecological soil health assessment in ways that traditional methods cannot, rather than presenting disconnected parallel concepts.
4. Provide a realistic implementation assessment including comprehensive discussion of research and development still required, standardization needs, economic barriers, and validation requirements for operational deployment across diverse soil-landscape conditions.

Please thoroughly address these comments in addition to both reviewer comments.

Kind regards,
Jonathan Maynard
SOIL, Technical Editor

Specific Comments:
1. Lns 275-278. A related example of this is the land capability (LCC) and land suitablity (FAO GAEZ) assessment frameworks.
2. Lns 288-289. In ecosystem management there are often intrinsic trade-offs between ecosystem services. A focus on ecosystem services tied to human values doesn't preclude incorporating an ecological perspective.
3. Lns 319-320. In most cases sensor-generated data are dependent upon conventional laboratory data to build calibrations and make predictions. Thus, the errors in the lab data will propagate in the sensor-based property predictions.
4. Lns 329-333. True, but all of this is dependent on sufficient data from conventional methods to calibrate sensor systems. For MIR and vis-NIR this is a significant initial investment. These sensor system are not operational out of the box.
5. Section 12. It is important to state that in most cases soil sensing data is not independent of conventional laboratory data. You need to first understand the properties, processes, and states of a system (determined from conventional methods) and its related sensor data to calibrate and model the desired property or class.
6. Figure 4. This is a central figure and should be supported by cited literature. Could include in a supplementary list or table.
7. Lns 357-359. Both vis-NIR and MIR require calibration, with vis-nir requiring sensor specfic calibration, while MIR is less susceptible to cross-instrument bias.
8. Lns 375-377. Please provide more specifics here and in other sections reviewing the literature. What are current limitation with available sensing technologies for estimating biolgoical properties? How well has spectra been modeled with ML approaches to estimate biological indicators?
9. Lns 385-386. What about TDR, FDF, capacitance sensors, Amoozemeter? Aren’t these also considered sensor data?
10. Section 12.2. I agree that this approach holds promise, but to implement you need to adequately characterize the reference conditions or states (e.g, healthy, moderatly degraded, degraded, etc). This approach requires some set of categorical reference classes.
11. On lines 433-434 your statement that "this methodology is now sufficiently advanced to be implemented, offering a transformative tool for ecological soil health assessment" is not adequately supported by the evidence presented. The manuscript itself acknowledges critical limitations that contradict this claim:
• "Some soil properties remain difficult to measure with sensing, e.g., infiltration and hydraulic conductivity, and research and development is needed" (lines 385-386)
• "Standardised protocols for their use in soil health assessments are still underdeveloped" (lines 351-352)
• "No sensors are yet available for measuring soil fauna, such as earthworms or arthropods" (lines 378-379)
• Emerging technologies like microfluidics are "still in early stages of development" (lines 384-385)
These acknowledged limitations directly contradict claims of sufficient technological advancement for operational deployment.
12. Figs 2 and 3 should be combined and expanded, providing examples to illustrate these connections. In its current form it is too general.

Dear Authors,

Thank you for submitting your revised manuscript on soil health assessment and proximal sensing technologies. This ambitious work addresses critical gaps in conceptualizing and operationalizing soil health assessments, and I appreciate your efforts to address the reviewers' concerns.
While you have resolved many of the initial issues, several areas still require development. The revised technical sections (Sections 10 and 11) are well done, with good balance between specificity and examples. Section 11.4 particularly stands out for its detail and should serve as a model for other sections.

The abstract and early sections need sharper definitions of key terms and clearer articulation of how your framework differs from and improves upon existing approaches. How would practitioners actually select indicators using your approach? What specific decision rules or criteria distinguish your multi-criteria selection process from existing methods? Additionally, the frameworks presented in Figures 2 and 3 must be internally consistent with each other and with the text, while remaining practically implementable by your intended audience.

The manuscript also needs stronger integration between the soil health review (Sections 4-8), your proposed framework (Section 9), and the sensing technologies (Sections 10-11). These components currently read somewhat independently rather than building toward a cohesive argument that demonstrates how the review informs your framework and how the sensing technologies enable its implementation.
Addressing these issues will significantly strengthen the manuscript and its contribution to the field. Please thoroughly address all points detailed in my full review, found in the pdf supplement, in your next revision.

Kind regards,
Jonathan Maynard
SOIL, Technical Editor

Dear Authors,
Thank you for your comprehensive and thoughtful revision of your manuscript "On Soil health and the pivotal role of sensing." I am pleased to inform you that your revisions have fully resolved all concerns identified in my prior review, as well as those highlighted by the two external reviewers.

The manuscript has been substantially improved through your revisions. The reduction in the number of sections and clarification of objectives significantly enhance readability and coherence. The new introductory subsection (1.1) effectively presents your main ideas and organizational structure from the outset, providing readers with an immediate understanding of the paper's purpose and contributions.

Your enhancements to the conceptual framework are particularly commendable. The explicit treatment of soil-specific potential and the clear distinction between ecological assessment and use-specific interpretation frameworks address a fundamental conceptual challenge in the soil health literature. The revised Figures 2 and 3, combined with the concrete mine-site rehabilitation example, substantially improve both the clarity and practical applicability of your proposed framework.

The strengthened abstract now effectively communicates why sensing technologies are not merely useful additions but essential tools for landscape-scale soil health assessment. This framing, integrated with the clearer articulation of your assessment framework, provides readers with a compelling understanding of your contribution to the field.

The considerable effort you have invested in this revision is evident throughout the manuscript. Your work now makes a clear and important contribution to advancing both the conceptualization and operationalization of soil health assessments.

I am pleased to recommend that your manuscript be accepted for publication. Congratulations on this excellent work, and thank you for your patience and persistence throughout the review process.

Kind regards,

Jonathan Maynard
SOIL, Technical Editor

Dear Authors,
Thank you very much for choosing SOIL as an outlet for your work and for working with the editor and reviewers to improve this manuscript. I am sorry that this manuscript has taken longer than we would hope to get to this stage and thank you for your patience and understanding.

I am pleased to inform you that after the revision process your manuscript is now accepted for publication in SOIL. I look forward to seeing it published.
Best wishes
Prof Jeanette Whitaker
Executive Editor