While the topic is relevant and timely, the manuscript would benefit from clearer explanations of data analysis, consistent use of terminology, and more thorough contextualization of the results. Detailed feedback is provided below.

Title

It is better to modify the title because the two agroforestry systems are not actually different. Both sites use a Gliricidia sepium-based agroforestry system, so there is no need to refer to them as two separate systems.

Here is my suggested title: Coupling of Soil Carbon and Water Cycles in Gliricidia sepium*-Based Agroforestry Systems in Malawi. Still I have question on the term “water cycles”.

Abstract

The abstract provides a clear overview of the study’s objectives, methodology, and key findings related to soil carbon and water dynamics in Maize-Gliricidia-based agroforestry systems and Maize monocropping in Malawi. It effectively highlights the importance of agroforestry in addressing climate challenges and improving soil health.

However, some areas could be improved for clarity and precision:

Consistency in Terminology: The abstract refers to “controlled setup,” which may be misleading since the experiments are conducted under field conditions. Clarifying this will avoid confusion.

Focus on Key Results: While the abstract summarizes results well, some sentences could be more concise. For example, the relationship between soil physical properties and water dynamics could be stated more directly.

Contextualization: The abstract would benefit from briefly mentioning the implications of the findings for sustainable agriculture or land management in Malawi.

No keywords were provided

Overall, the abstract is informative but could be polished to improve readability and impact.

Introduction

I noticed some redundancy in the introduction section of the article. For example, the effects of intercropping Gliricidia trees with maize are repeatedly discussed in relation to soil structure, soil fertility, soil organic carbon (SOC) content, carbon stocks and stability, water dynamics, and maize yield. These points should be streamlined and organized clearly to avoid repetition.

Additionally, I observed a disruption in the flow of ideas within one paragraph. You wrote, “Consequently, in this study we examine the link between carbon input and soil hydrology,” which is immediately followed by, “There is still a lack of knowledge about the extent to which carbon-induced short- and long-term changes in soil structure affect water fluxes in these systems.” This sequence weakens the coherence of the introduction.

I recommend revising the introduction to improve clarity, coherence, and engagement. The background should succinctly summarize existing knowledge, highlight the specific knowledge gap, and effectively convey the importance of your study without redundancy. It would also be helpful to clearly and concisely differentiate your research from previous studies such as Chirwa et al. (2007), Hoffmeister et al. (2025), Kerr (2012), Kirsten et al. (2021), Maier et al. (2023), and Makumba et al. (2006, 2007).

Line 72: What do you mean by "farmers might be concerned"? Is there any evidence or findings that show how farmers perceive the impact of agroforestry systems (AFS) on soil evaporation?

Line 64: You should clearly define what the tree component is?

Line 72. Some of the findings are not fully reviewed or presented in the introduction section. For example, the relationship between increased SOC and soil evaporation is still debated in the literature and may depend on contextual factors such as soil texture and climate, as reported by Feifel et al. (2024).

Line 76. The findings were not fully presented while making the argument. However, they are still influenced by seasonal variation. For instance, Chirwa et al. (2007) reported that the available soil water content at the start of the cropping season was generally lower in tree-based systems, indicating that trees likely continued to extract soil moisture throughout the dry season.

Line 83. Lack of information is provided concerning the distance between the two sites. Sites that are 316 km apart were generalized as being in the same climatic zone. Does this make sense? If so, please show us on a map, using a DEM or a table with long-term climate data from meteorological stations.

Line 103. Sometimes you use the wrong words. For example, calling it a "controlled agroforestry experiment" is odd for an experiment conducted under field conditions..

It is better to include the hypothesis! It would strengthen the manuscript to explicitly state the study’s hypothesis (or hypotheses) in the introduction. Presenting the hypothesis provides readers with a clear understanding of the research’s expected outcomes and the rationale behind the study design. This also helps in framing the results and discussion, allowing the audience to assess whether the findings support or refute the initial assumptions.

Method

Line 102: The map is not sufficiently explanatory, as it lacks essential elements and does not clearly represent the study area’s landscape and elevation. Could you please provide a DEM map of the study area that includes all necessary features, such as coordinates, a legend, and other relevant details? This DEM map will help to clearly highlight the climate zones within your study area.

Line 103. Misleading information is included, such as referring to the study as a controlled agroforestry experiment. A controlled experiment has a very different meaning, whereas the agroforestry experiment in question was conducted under field conditions.

Line 105: Information that should be presented in the introduction, which could help to highlight the research gap, is misplaced here in the Methods section. For example, see line 105.

I feel that it is better to provide topics for each section of the methodology, such as: Study Area Description, Experimental Design, Description of Agroforestry System / Cropping System, Sampling Procedures, Measurement Techniques, Data Collection on Environmental Variables, Laboratory Analysis, Data Analysis Methods, Quality Control and Assurance, and Ethical Considerations or Permissions.

The management practices in the control (maize monocropping) were not explained at all. If it was conducted without any fertilizer, it does not reflect the reality of maize production in Malawi or other African countries. It would make more sense to compare maize production under local fertilizer rates and typical management practices. The experiment would have been improved by including three treatments: control (no fertilization), T1 (fertilizer at the recommended local rate), and Maize-Gliricidia based agroforestry.

Line 115: There is a lack of consistency in reporting temperature: for the Chitedze site, the mean annual temperature is reported, whereas for the Makoka site, the mean daily temperature is given.

Line 116: Lack of consistency in soil group classification by the IUSS Working Group: For the Chitedze site, you cited IUSS Working Group (2014) for the classification of Chromic Luvisols, while for the Makoka site, you used IUSS Working Group (2022) for Ferric Lixisols. I suggest using the latest version (e.g., IUSS Working Group, 2022) for both sites. Typically, such data are established at the country level, and you may be able to find updated classifications for both locations in the newer version.

Figure 1. Figure 1 requires changes based on the above comments.

Line 125: Would the ridges in the maize plot intercropped with gliricidia trees affect soil sampling for bulk density and other parameters that require undisturbed soil samples for analysis?

In line 134. Previous data were included in this article, but details about the data and the source link (local or international repository) were not provided. I personally recommend presenting this information in the appendix section of the article. Additionally, you should mention it in the introduction for example, by stating that previous work has addressed certain aspects, but further analysis is still needed due to a lack of [specific information or data] or inconsistencies in the results (short- or long-term).Furthermore, It is a fact that both pedological and hydrological characteristics vary with time and season, so you should explain why you chose to include data from 2019 and 2021.

Line 135: Some of the topics seem overly broad and include irrelevant information. It would be better to provide concise main topics and split the rest into subtopics. For example, having 'Soil sampling with an auger' as a main topic in the article seems quite unusual.

Line 138: There is a lack of standardized names for sampling instruments. Use ‘Kopecky rings’ instead of ‘small and large cylinders,’ as Kopecky rings are standardized tools for collecting undisturbed soil samples in the field. Since there are ridges inside the plot, how did you manage to collect undisturbed soil samples from these areas? To what extent can the samples collected from this site be considered truly undisturbed?

Line 142: There is a lack of information regarding the soil sampling system and sample collection. Since there are ridges inside the plots, how did you manage to take samples from both disturbed and undisturbed soil depths (e.g., see line 170) in both treatments at the two sites? Furthermore, some studies report that in tree-based agroforestry systems and annual crop production areas, the 31-90 cm soil layer typically represents the depth where leached nutrients accumulate and where root growth contributes organic matter and nutrients. Do you think sampling only the 0-10 cm and 10-20 cm layers is sufficient to represent the actual soil conditions at the site? I also have doubts about the depth ranges (e.g., 0-10 and 10-20 cm); I personally suggest using 0-10 cm and 11-20 cm ranges.

Lines 141-147, line 170, and line 199 show inconsistency in sample collection for physicochemical and hydrological data collection. Sometimes you use depth intervals of 0-10 cm, 11-20 cm, other times 0-20 cm, or specific depths like 5 cm, 7 cm, 10 cm, 15 cm, 25 cm, and 60 cm, which makes it very difficult to follow the overall research flow. There is consistent inconsistency in sampling and sample depth selection, making it hard to interpret the results. This variability in sampling could itself introduce additional variation beyond the treatment effects (control and Gliricidia agroforestry plots).

Line147-150: The sampling times vary, with some campaigns conducted in 2021 and others in 2022, which is methodologically challenging for soils in tropical areas. Both soil and hydrological characteristics change over time, and using data from different periods could complicate the results and overall findings of this research.

Line 154: How reliable is the distilled water method for measuring water-dispersible clay (WDC), considering that some clay particles are strongly bound and will not disperse without the use of chemical dispersants such as sodium hexametaphosphate (Na₆P₆O₁₈)? Furthermore, the results can be influenced by soil type.

Line 154: You analyzed CEC but you don’t analyzed Na⁺? Please also correct the notation for Ca²⁺, Mg²⁺, and K⁺.

Line 164: What are the similarities and differences between this study and the one by Hoffmeister et al. (2025)? Is there any connection to this study (e.g., in terms of data, methods, etc.)? What is the purpose of mentioning it here?

Line 173: The majority of the measurements, such as hydraulic conductivity (Ksat), were conducted in the laboratory, despite the availability of accepted field measurement methods. Why choose to measure Ksat using laboratory instruments in Germany when field measurements using a double-ring infiltrometer or Guelph permeameter are easier and more cost-effective than transporting soil samples to a distant location?

Line 194-195: The falling-head method is generally recommended for fine-textured soils due to its sensitivity to low permeability. Could you clarify why this method was selected, especially if the soil in your study includes coarser textures? For example Guelph permeameter and double-ring infiltrometer.

Line 204: Despite the actual rainy season being from November to April, why were you interested in collecting some hydrological data (e.g., water flux data such as soil moisture and matric potential) from March to May 2022? Did you also consider calculating antecedent soil moisture content?

Line 210: The soil water storage change was calculated based on the difference between two successive soil water content measurements. At what time intervals did you conduct the soil moisture and matric potential measurements, and why did you select those intervals?

In general, there is no information on data analysis, such as the type of software used to analyze the soil and hydrological characteristics, or how the mean values of these characteristics were compared between treatments at the two sites. It is also difficult to conduct ANOVA with only two treatments. I suggest performing a two-factor factorial analysis for each site, introducing treatment and depth as factors. Additionally, if interested, you could consider treatment and site as two factors to analyze their interaction effect.

Result

Why do you want to compare the different soil and hydrological characteristics between sites? It is quite clear that the soil classes at the two sites are different (i.e., Chromic Luvisols vs. Ferric Lixisols). Differences are expected due to soil formation processes, parent materials, and stages of weathering.

You are only presenting the results in the Results section, but it is important to include explanations of your own reasoning, justifications, and the implications of the high and low values of the soil and hydrological characteristics between treatments.

Table 1. No information about the sand, silt and clay faction for Makoka site 0-20 cm depth ranges.

The entire Results section lacks statistical t-test analyses with significant p-values and letters indicating differences between treatments (e.g., a, b, c in mean values in the tables or figure bars). In general, the soil physicochemical and hydrological characteristics are presented simply as high or low without any statistical comparison or significance values.

Table 1. The table captions sometimes include too much information, such as abbreviation details. They should follow the standard format of the journal.

As described in the Methods section, the presented result data show a lot of inconsistency in depth ranges for soil physicochemical and hydrological characteristics, which makes it quite confusing and hard to understand the overall flow of the results.

There is inconsistency in the number of samples used for analysis in the results presented in the tables. For example, results analyzed with 10 samples at one site are compared with results from only 5 samples at the other site. For example in Table 1, the soil characteristics from 2019 (Chitedze) with a larger sample number were compared with those from the other site (Makoka) in 2021, which had only 5 samples. This is methodologically incorrect, if you don’t you proper analysis tools for such type of data. Additionally, there is no information on the number of replications for each treatment at the two sites.

Figure 2. It is very hard to understand and visualize the differences in Figure 2a, which seems to be based on subjective judgment. In Figure 2b, at the Makoka site, the experiment is designed as a randomized complete block design. It is important to show how the other replications look so that it is easier to visualize the differences. In general, since these figures are not the major aim of this research, it would be better to include them in the supplementary section of the article. Furthermore, no standard sampling procedures was reported for this data.

Table 2-: It would be better to move this table to the supplementary section, as it is not directly relevant to the Results section because it presents results from previous research. I am unsure of the intention behind including secondary data in the Results section, especially since soil properties (such as soil carbon) change over time. You could discuss these changes in the Discussion section while referring to the data in the supplementary materials.

There is also mixing of sections, with literature frequently cited in the Results section, reflecting an organizational problem. The manuscript should be structured according to the journal’s guidelines. Furthermore, some information that belongs in the Methodology section is instead presented in the Results section; see, for example, lines 265 and 304-305.

Figure 3. A beautiful figure was presented but they statistically don’t show anything and seem like static, meaningless figure.

Line 251. You are comparing the C content between sites. In my opinion, these two locations are incomparable due to differences in sampling and methodology. It would be better to focus on the treatment effects at each site separately.

Figure 4: The relationship between WDC and Colf was negative, but the R² value (R² = 0.65) is positive. Additionally, the legend for AFS is not clearly identified in Figure 4.

Line 265: sometimes you compare soil characteristics between sites, but if interested, you could instead perform a two-factor ANOVA to examine the interaction effect of site and treatment. As I understand it, you want to evaluate the effect of Maize-Gliricidia based agroforestry compared to maize monocropping; therefore, it would be better to compare these results separately for each site.

Line 274: The treatment differences (per depth) for the small cylinders were tested using the Mann-Whitney U test, as the sample size was sufficient and results showed no significant difference. However, this is not the correct place to explain the analysis method; such details should be included in the Methodology section.

Line 278: Bulk density (BD), porosity, and Ksat values did not show any statistical evidence of differences between treatments at the two sites. For example, although Ksat was higher in the Gliricidia treatment than in the control, this difference was not statistically significant (see Figure 5).

Why don’t you show the correlation between organic carbon and both bulk density and Ksat for the two treatments?

Line 292: Sometimes, measurement values from the laboratory and the field are presented in the Results section for example, retention curves (tension and soil water content) but there is no explanation or statistical comparison between the two sets of measurements. Since the methods used are standardized, it is unclear why repeated measurements were made, especially when the study’s focus is not on evaluating these methodologies. This presentation is confusing (see Figure 6 results).

Figure 6. The figures contain many values for different hydrological characteristics but lack labels for each panel. Please add labels such as Soil Water Content (a) Chitedze, (b) Makoka, and PAW (c) Chitedze, (d) Makoka at the top of Figure 6, and explain them clearly in the figure caption. This will enable you to refer to them easily after presenting the results.

Sometimes the result for one treatment is high at one site but low at the other. For example, in line 298, in Makoka, PAW in the control showed “slightly higher values” compared to the AFS treatment; however, in Chitedze, higher PAW values were recorded in the AFS treatment. There is no reasoning or explanation provided for these contrasting results throughout the Results section.

Line 305: Did you check the antecedent moisture content and its relationship with overall water content and matric potential?

Line 312. What is the reason for the strong drying after rainfall, even in the gliricidia treatment, based on your observations or experience? Could the difference in soil water content between the sites be due to variations in geology or parent material?

Figure 7 lacks labeling for P and WC in both the control and gliricidia treatments.

Line 335: The statement ‘the water slowly percolated downwards in the gliricidia plot as demonstrated by the sequential storage increases with increasing depth’, does this truly reflect real field conditions? I have doubts because real-world soil water dynamics are often more complex due to factors such as soil heterogeneity, lateral flows, plant activity, and varying environmental conditions. Therefore, relying solely on this observation may not fully capture the actual behavior of water movement. Additionally, the implications of this for shallow- and deep-rooted plants should be elaborated. Furthermore, the relevance of these findings to the specific climatic zone and potential supplementary irrigation strategies should also be discussed.

Discussion

Figures are misplaced for example, Figure 10 is placed inside the discussion section instead of the appropriate section.

Sometimes unreasonable generalizations are made, even though the facts are only presented in the Results section. For example, in line 356, it states that the soil at the Chitedze site already has a high carbon saturation level. Did you calculate the Carbon Saturation Index (CSI), which is the ratio of observed SOC to the estimated maximum SOC storage capacity, or use other metrics such as the Mineral-Associated Organic Carbon to Clay + Silt Ratio (MAOC/CS)? In tropical climates, reaching carbon saturation is more challenging than in temperate regions due to higher microbial activity.

Line 357: Some supporting literature is presented in the discussion without relevant information. These references are off-topic, not related to agroforestry systems or maize, and are from non-tropical climatic zones. In research focused on the tropics, your citations come from Japan and Germany. Couldn’t you find any literature related to tropical regions?

Line 366: Have you identified any literature on the relationship between organic matter and soil aggregation in tropical regions, particularly in Africa? You cite Bronick and Lal (2005), but the argument you present is not consistent with the WRB/FAO classification (i.e., Alfisols are distinguished from Luvisols and Lixisols).

Line 376. Generalizing the results as ‘high’  by what index did you classify ‘high’ and ‘very high’? I am also surprised that there was no statistical difference in pedogenic oxide values between the two treatments, yet it was reported that these contribute to the potential structural benefits typically attributed to increased SOM in AFS treatments.

Line 390. The fact is that there is no statistical difference in bulk density and Ksat between the two treatments under different management practices. How do you support your argument in light of this?

Line 397: We did not see any statistical evidence showing a variation in BD and Ksat between the treatments (e.g., Figure 5)

4413: “The treatment differences appeared smaller than differences in depth” this means that depth is another important factor, or that depth mattered more than the treatment in explaining the differences. I suggest conducting a two-factor analysis to assess the interaction effect between treatments and depth.

445-450: In the gliricidia treatment, water movement down the soil profile is context-dependent, particularly influenced by soil texture. What are the implications of this?

Line 490: This conclusion is difficult to accept because it appears to be based on simple observation without a proper sampling procedure for plant growth and health attributes. Please review how samples are taken with replicates in experimental plots in other published studies.

Line 498: Does this mean that the effect of Gliricidia residue input on CEC is site-context dependent?

Conclusion

Line 511: “In maize and gliricidia intercropping, we saw a clear treatment effect on soil nutrient and C contents as well as on soil structure.” However, regarding the treatment effect, no statistical differences were observed between treatments at either site. You simply label the values as ‘high’ and ‘low’ based on the numbers, which is not scientifically valid. Moreover, the treatment effects were not consistent across both sites for all parameters. Please review your tables and figures.

Line 518: “In the context of climate change, we saw that some of the envisioned challenges for agriculture in Southern Africa can be alleviated with the adoption of AFSs.” However, your research does not consistently support this conclusion. How did you arrive at this statement?