CO₂ Emissions in Layered Cranberry Soils under Simulated Warming

Round 1

Reviewer 1 Report

1. Introduction section must be revised and add most recently published research as ref. 

2. Line 53-55 should be clarifying further.

3. In MM mentioned the tools used for soil sampling in the field. Also mention field load of the soil at the time of collection?

4. Revise it and make it better by using multiple color codes "Figure 1. Soil properties of cranberry soils: A) C stock, B) C:N ratio, C) bulk density, D) pHCaCl2, E) total porosity, F) water content."

5. Research link is missing and very irrelevant discussion in lines 201 - 210.

6. Future research and way forward is missing and add how it will contribute to meet SDGs 2030. 

Author Response

Reviewer #1:

1. Introduction section must be revised and add most recently published research as ref.

Unclear comment. We first place cranberry ecosystems in the global perspective. We then focused on the most relevant references focusing on cranberry soils, soil layers and temperature. There were 22 references up to 2021, six from 2018 on, in the introduction. We added two recent references in the discussion section l. 206-207 and l. 246-250.

2. Line 53-55 should be clarifying further

See l. 56-62: We hypothesized that activation energy of soil organic matter (SOM) decomposition and Q₁₀ differ in alternate sand and organic matter layers due to the differential C/N ratio and decomposition degree of organic matter in two differently managed cranberry soils. The aim of this study was to measure the decomposition rate of SOM in layered cranberry soils as a function of management (conventional vs. organic), soil layer, incubation time and temperature under controlled environments to assess the differential effects of global warming on soil C storage in cranberry soils.

 

3. In MM mentioned the tools used for soil sampling in the field. Also mention field load of the soil at the time of collection?
4. 80-81: Soil samples were collected for physical analyses in spring 2018. Three soil layers were sampled (0-10; 10-20; 20-30 cm) at four places per site using cylinders (diameter = 5.5 cm, height = 7.6 cm).
5. 95-96: Soils were sampled at three depths (0-10 cm, 10-20 cm, 20-30 cm) and four locations in each field (785 ml per sample using cylinders 10 cm in height and 10 cm Ø) and introduced in plastic bags.
6. Revise it and make it better by using multiple color codes "Figure 1. Soil properties of cranberry soils: A) C stock, B) C:N ratio, C) bulk density, D) pHCaCl2, E) total porosity, F) water content.

Done

 

5. Research link is missing and very irrelevant discussion in lines 201 - 210.

Irrelevant discussion was removed. We added the possible contribution of mycorrhizae to be examined in future studies l. 246-250. We hope that the revised section is adequate.

 

6. Future research and way forward is missing and add how it will contribute to meet SDGs 2030. 

See l. 220-221 and l. 246-250

Author Response File: Author Response.pdf

Reviewer 2 Report

The topic undertaken is valid and the research is important. However, I see a few issues that may be explained better.

1.      Introduction

Line 53: Q₁₀ should be explained the meaning at the first use, not later in the text

2.      Materials and methods

Line 67 and 68 ‘Soil series were saint Jude and Sainte Sophie… what do you mean by that? The explanation is needed.

Line 77 when calculating C stock in the equation the thickness of the soil layer should be included

Line 79 what is P_d? the explanation is needed.

3.      Results

Why are the soil properties not described in the same order as they are presented in Figure 1?

Why are some soil properties presented in Figure 1 not described in the text, not even mentioned?

Line 140-144 How was the percentage calculated?

Discussion

Line 164: What do you mean by SOM regulates SOM turnover

Line 171: any example?

What about differences between sites mentioned in the Materials and methods (organic farming versus conventional one)?

Does the organic farming system allow for such a big doses of chemical fertilizers to acidify the soils (pH <4)?

Lines 176 – 186 the whole section is the literature citing without referring to your own results and situation

Lines 199-200 How was it shown in this paper? In your or in the cited papers [17, 47]?

Lines 208-210 Have you measured the C of microbial biomass?

Line 210 Why do you think that the acidity contributes to the protection of SOM? Usually acid SOM dissolves in water and is easily washed down. Under acidic soil condition fungi develop which are  good decomposers of SOM. Why is it the contrary in cranberry soils?

 

Author Response

Reviewer #2:

The topic undertaken is valid and the research is important. However, I see a few issues that may be explained better.

1. Introduction

Line 53: Q₁₀ should be explained the meaning at the first use, not later in the text.

1. 17-18 and 53: Q₁₀ coefficient, the increase in reaction rate per 10°C.
2. Materials and methods

Line 67 and 68 ‘Soil series were saint Jude and Sainte Sophie… what do you mean by that? The explanation is needed.

1. 69-72: Soil series is soil’s name on national classification schemes and soil maps. Morphogenetic classification is reported. ‘Soil series were the Saint-Jude series at site #45 and Sainte-Sophie series at site #9, both classified as Humo-Ferric Podzols in the Canadian System Haplorthods in the U.S. Soil Taxonomy, and Orthic Podzols in the World Reference Base for Soil Resources.’

Line 77 when calculating C stock in the equation the thickness of the soil layer should be included

The C stock is computed by multiplying soil bulk density (g cm-3) by carbon content (%) to represent the mass of carbon per soil layer (Eq. 2).

Line 79 what is P_d? the explanation is needed.

This is the symbol for particle density. We replaced Pp (typo) by Pd l.93.

3. Results

Why are the soil properties not described in the same order as they are presented in Figure 1?

Done l. 143-152

Why are some soil properties presented in Figure 1 not described in the text, not even mentioned?

Done l. 157-158

Line 140-144 How was the percentage calculated?

As % of across-layer emissions over the incubation period, l. 166, 168, 169.

Discussion

Line 164: What do you mean by SOM regulates SOM turnover

Removed (typo)

Line 171: any example?

Provided in l. 216-219

What about differences between sites mentioned in the Materials and methods (organic farming versus conventional one)?

No significant difference (p-value > 0.05), see l. 158 and Figure 2.

Does the organic farming system allow for such a big doses of chemical fertilizers to acidify the soils (pH <4)?

There is no difference between conventional and organic farming on S dosage to acidify the soil, the objective being mainly to tackle nitrification and abate weeds. But this irrelevant aspect was removed from discussion.

Lines 176 – 186 the whole section is the literature citing without referring to your own results and situation

Section 4.1 revisited.

 

Lines 199-200 How was it shown in this paper? In your or in the cited papers [17, 47]?

Data retrieved from literature (l. 244-251) for comparison with our results.

Lines 208-210 Have you measured the C of microbial biomass?

No, but this could be addressed in future research. See l. 247-251

Line 210 Why do you think that the acidity contributes to the protection of SOM? Usually acid SOM dissolves in water and is easily washed down. Under acidic soil condition fungi develop which are  good decomposers of SOM. Why is it the contrary in cranberry soils?

This is indeed a complex problem. We agree that this partial discussion goes beyond the objective of the paper. The availability and illuviation of soluble carbon, metagenomics and microbial biomass should be addressed in future research on cranberry soils.

Author Response File: Author Response.pdf