Review Reports - Natural Strategies for Increasing Yields: The Role of Plant Extracts and Micronutrients as Natural Resources in Sustainable Intensification

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript entitled " Natural Strategies for Increasing Yields: The Role of Plant Extracts and Micronutrients as Natural Resources in Sustainable Intensification" reviews the application of plant biostimulants and micronutrients in sustainable agriculture, closely aligning with the core goals of circular economy and sustainable intensification. The research perspective has strong practical significance and academic value. Then future research directions are proposed, which meets the requirements of a literature review. The manuscript has a complete structure and clear logic while some improvements will enhance the information flow and content. I recommend the following be undertaken:

1 The elaboration on the mechanism of action of plant biostimulants is superficial. Add the physiological and molecular mechanisms of bioactive compounds in plant biostimulants.

2 The manuscript focuses more on theoretical sorting and research examples, but lacks in-depth discussion on the practical application limitations and solutions of plant biostimulants and micronutrients. The author can discuss the practical application limitations of the two technologies, and put forward targeted solutions (e.g., optimizing extraction processes to reduce costs). Then refine the future research directions to make them more specific and operable.

Author Response

We would like to thank the Reviewer for the thorough evaluation of our manuscript. We are pleased that the work has been received positively, and we are sincerely grateful for the identification of gaps and inconsistencies.

The manuscript has been revised and expanded in accordance with the provided comments and suggestions. We believe that these changes, guided by the Reviewer’s recommendations, have significantly improved the quality and clarity of the work.

Below, we present a detailed summary of the revisions introduced in the manuscript.

I recommend the following be undertaken:

1 The elaboration on the mechanism of action of plant biostimulants is superficial. Add the physiological and molecular mechanisms of bioactive compounds in plant biostimulants.

Lines 143–178: The description of limitations and challenges was added, and it was reiterated that their effects are specific to plant species as well as environmental conditions.

Lines 179–199: Information on limitations and challenges was added, and it was reiterated that their effects are specific to plant species as well as environmental conditions.

The problems and challenges in current research rendering future research has been dealt as follows:

Lines 179-199: New information on limitations and challenges has been introduced, but reiterated that they are specific to plant species as well as environmental conditions.

Additionally, the integrated role of plant biostimulants and micronutrients has been strengthened in the revised (section 3.4.5) manuscript by adding a dedicated discussion of their synergistic agronomic and physiological effects. Recent representative studies and empirical examples of biostimulant–micronutrient synergy have been introduced.

Reviewer 2 Report

Comments and Suggestions for Authors

This review focuses on natural strategies for increasing crop productivity within the framework of sustainable intensification, with an emphasis on the integrated role of plant biostimulants and micronutrients. The research topic is closely aligned with the core issues of global food security and the sustainable utilization of natural resources, and it possesses significant theoretical and practical value. Overall, the review has a clear research framework and rigorous logic.

The prominent advantages of this paper are reflected in three aspects: First, the research perspective is innovative, breaking the limitations of a single discipline. It integrates multi-disciplinary perspectives of plant physiology, coordination chemistry, and resource management, and proposes a conceptual framework in which plant-derived extracts and micronutrient complexes act as complementary tools to support circular and resource-efficient agricultural systems, making up for the deficiencies in existing research regarding the analysis of their synergistic effects and resource orientation. Second, the research orientation is clear, based on the utilization of renewable resources and responding to the needs of sustainable agricultural development. The research conclusions have strong guiding significance for promoting the resource utilization of agro-industrial by-products, optimizing crop nutrition management, and realizing green agricultural development. The keywords are accurately selected and can effectively reflect the core content of the article.

At the same time, there are still some details that can be further improved to enhance the completeness and depth of the review: First, it is recommended to supplement the latest research results in related fields in recent years (especially representative studies in the past 3-5 years), enrich the empirical cases of the synergistic effects of biostimulants and micronutrients, and enhance the timeliness and persuasiveness of the review. Second, it is advisable to appropriately expand the differences in the application effects of plant-derived extracts and micronutrient complexes under different crop types and soil conditions, so as to provide more specific references for their precise application in actual agricultural production. Third, the abstract mentions the "integrated role of biostimulants and micronutrients", and it is necessary to further clarify the specific mechanisms of their synergistic regulation of crop growth and improvement of resource use efficiency, making the conceptual framework more operable.

In summary, this review has a novel research topic, substantial content, clear logic, and prominent innovation and application value. It can meet the publication requirements after minor revision. It is recommended that the authors improve the content in combination with the above comments, focusing on supplementing the latest research cases and details of synergistic mechanisms, so as to further enhance the academic quality and application value of the review.

Author Response

Below, we present a detailed summary of the revisions introduced in the manuscript.

The section 3.4.5. has been revised accordingly. Recent representative studies from the last 3–5 years were added to strengthen the timeliness of the review and to provide additional empirical examples of the synergistic effects of biostimulants and micronutrients. The discussion was also expanded to better reflect crop- and soil-dependent differences in the performance of plant-derived extracts and micronutrient complexes, with emphasis on their relevance for more precise agricultural application. In addition, the mechanistic basis of their integrated action was clarified by highlighting their combined effects, thereby making the conceptual framework more operational.

Second, it is advisable to appropriately expand the differences in the application effects of plant-derived extracts and micronutrient complexes under different crop types and soil conditions, so as to provide more specific references for their precise application in actual agricultural production.

In the section 3.4.5 : The discussion on crop- and soil-dependent differences in the effects of plant-derived extracts and micronutrient complexes has been extended in the following way:
Lines 763-769: Added practical application limitations and targeted solutions.
Lines 779-782: Refined future research directions to make them more specific and applicable

Third, the abstract mentions the "integrated role of biostimulants and micronutrients", and it is necessary to further clarify the specific mechanisms of their synergistic regulation of crop growth and improvement of resource use efficiency, making the conceptual framework more operable.

The integrated role of plant biostimulants and micronutrients has been strengthened in the revised manuscript by adding in the section 3.4.5 a dedicated discussion of their synergistic agronomic and physiological effects. This topic is very fresh, thus it has only a few clearly presented reports.

Reviewer 3 Report

Comments and Suggestions for Authors

Review of resource 4229623 is devoted to the pressing topic of sustainable agricultural intensification. The review is logically structured, easy to understand, systematic, and well-reasoned. This is a good, classic scientific work.

Comments:

1) In the abstract, the authors noted the integrated role of plant biostimulants and micronutrients, which seems justified. However, the review itself does not devote sufficient attention to this integration; it is recommended to strengthen this emphasis.

2) For example, sections 2.2.3 and 3.4.5 could be logically combined. Here's how it could be done. A new and relevant area is the artificial humification of lignocellulosic biomass, including straw and husks, which is recommended to be reflected in Table 3. Thus, lignocellulose can be used to produce not only extracts but also humic and fulvic fertilizers.

Some examples of international work in this area:

Patil SKP, Lund CRF. Formation and growth of humins via aldol addition and condensation during acid-catalyzed conversion of 5-hydroxymethylfurfural. Energy Fuels 2011;25:4745-55. https://doi.org/10.1021/ef2010157
Yang X, Tan B, Kong D, et al. Preparation of Artificial Humic Acid from Cotton Stalk and Saline-Alkali Soil by Synergistic Catalytic Pyrolysis and its Potential Agricultural Application. Journal of Environmental Chemical Engineering. 2023:118948. doi: 10.1016/j.jece.2025.118948.
Yang F, Zhang S, Cheng K, Antonietti M. A hydrothermal process to turn waste biomass into artificial fulvic and humic acids for soil remediation. Science of the Total Environment. 2019; 686:1140-1151. doi:10.1016/j.scitotenv.2019.06.045
Kong D, Wang G, Zheng J, et al. Sustainable Synthesis of Artificial Humic Substances from Bamboo Powder by FeCl₃-Catalyzed Low-Temperature Pyrolysis for Cadmium Contaminated Soil Remediation and Carbon Sequestration. Environmental Research. 2023:123319.
Shao Y, Bao M, Huo W, et al. Production of artificial humic acid from biomass residues by a non-catalytic hydrothermal process. Journal of Cleaner Production. 2022;335:130302. doi:10.1016/j.jclepro.2021.130302
Song C, Zhang L, Wang J, et al. Lignocellulose hydrothermal artificial humic acid production: Reaction parameters screening and investigation of model/real feedstock. Journal of Analytical and Applied Pyrolysis. 2024;183:106739. doi:10.1016/j.jaap.2024.106739
Tu, W.-C., Hallett, J.P., 2019. Recent advances in the pretreatment of lignocellulosic biomass. Curr. Opin. Green Sustain. Chem. 20, 11–17. https://doi.org/10.1016/j.cogsc.2019.07.004

Author Response

Below, we present a detailed summary of the revisions introduced in the manuscript.

The integrated role of plant biostimulants and micronutrients has been strengthened in the revised manuscript by adding into the section 3.4.5 a dedicated discussion of their synergistic agronomic and physiological effects. Recent representative studies and empirical examples of biostimulant–micronutrient synergy have been introduced.

Section 3.4.5: Added the emerging topic of artificial humification of lignocellulosic biomass and its relevance as a circular source of humic- and fulvic-like materials. Several articles proposed by the Reviewer were cited, according their direct relevance to the topic.

Table 3 was supplemented with lignocellulosic biomass-derived artificial humic- and fulvic-like materials.

However, sections 2.3.3 and 3.4.5 were retained as separate because they address different functional contexts in the manuscript, while their conceptual link has now been made clearer in the revised discussion.