Locally Available Organic Waste for Counteracting Strawberry Decline in a Mountain Specialized Cropping Area

Round 1

Reviewer 1 Report

The manuscript ID: sustainability-1135402 presents the usages of organic waste for counteracting the strawberry decline in a mountain specialized cropping area during the two negative periods. The obtained results are very interesting because they show the importance of beneficial microorganisms (bacteria, fungi) in the process of agricultural production, and their positive impact on the growth of strawberries. Besides, the positive impact of organic waste on the population of beneficial microorganisms is shown.

But despite good research, I have a few suggestions that could improve knowledge about the impact of organic waste on increasing strawberry yields:

1. The paper does not provide data on the chemical composition, ie how many and which micro-and macronutrients there are in organic waste. This is very important because they have got a huge impact on the microorganisms and their growth,
2. Also, there is not any data about the number of the cells or spores of certain detect microorganisms in the soil,
3. The manuscript is mainly the presentation of statistical data and the discussion is insufficient. The discussion must be improved.
4. The results of the quality of the fruits after the treatment are not shown (mass, color, the content of secondary plant metabolites, and antioxidant capacity).

In conclusion, this paper does give advance the field significantly from the current state of knowledge and my suggestion is to publish it after the major revision.

Author Response

Specific answers to the Referee 1.

1. The paper does not provide data on the chemical composition, ie how many and which micro-and macronutrients there are in organic waste. This is very important because they have got a huge impact on the microorganisms and their growth

ANSWER The main chemical feature of Digestate and Compost were reported in subchapter “2.3.1 Pre-plant treatments and field trial” in Material and methods. As material were certified about the composition suitable for the use for amendments according the national rules and the heavy metal content were under the limits their composition was not reported. In response to the reviewer request, in the new revise version, a table of the composition of those amendment was added as Supplementary material S1 and quoted in the sub-chapter 2.3.1.

2. Also, there is not any data about the number of the cells or spores of certain detect microorganisms in the soil.

ANSWER The quantitative of Pseudomonas and Cylindrocarpon in soils were evaluate with qPCR essentially aiming at correlating their specific amplicon r quantity with strawberry production. The inoculum in soil of the latest microbial populations was not evaluated with culture-based methods. Conversely, strawberry root colonization by soil-borne fungi was expressed as colony forming unit per root explant. In this case, root infection frequency evaluated as CFU per root explant and expressed as percentage in Figure 1 is a culture-based measure which acts as indicator of soil inoculum of the different fungal root endophytes of strawberry.

3. The manuscript is mainly the presentation of statistical data and the discussion is insufficient. The discussion must be improved.

ANSWER Discussion has been improved quoting also further referenced. Please see new parts in the manuscript version with track change

4. The results of the quality of the fruits after the treatment are not shown (mass, color, the content of secondary plant metabolites, and antioxidant capacity).

ANSWER The result of the quality of fruits were not shown in the original version because they did not differ significantly between treatments in each of the year of the trial. In the new revised version,

sub-chapter 2.3.2. The methodology applied for evaluate fruit quality was better described

Subchapter 3.2.1 Differences between quality features were more indeed described and data were shown in a new table (Table 4). The further tables were re--numbered.

Author Response File: Author Response.pdf

Reviewer 2 Report

Biggest flaw I observed had to do with whether or not trials/experiment were repeated.  It appears that the greenhouse trials were not properly repeated and represent a single run of the research.  However, I don't think this is clearly outlined in the manuscript as submitted.  Even if the trials were properly repeated, the manuscript needs a significant amount of work as I found numerous grammatical as well as sentence structure issues.  The authors should be urged to have someone that speaks English as a first language read through their work before submitting to a journal for review.  Moreover, based on some of the trials as conducted in the field and where you have what could be considered as "repeated measures", the authors should consider consulting with a statistician because I don't think that the authors conducted the proper statistical analysis.

Author Response

See the revised version and the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Please, see and follow my attached notes.

Comments for author File: Comments.pdf

Author Response

Thank you, All the suggested changes were performed

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Dear Authors;

now everything is corrected and the article is much better. 

Kind regards

Author Response

Let me thank the referee 1 for the hlep to improve the manuscript

Reviewer 2 Report

You did a single treatment on a single field and observed the effects of those treatments over a two year period.  If you had done this work in multiple field locations I could see where this might have a chance as being an acceptable scientific study; however, as it stands, you do not have any repeatability of the research as conducted in this particular paper.  My recommendation to you as authors is to repeat the studies in MORE locations over a longer period of time.  Then, when completed (and I would suggest a minimum of three locations and nothing less than three years of observation) you need to consult with a statistician as to the proper analysis to be conducted.  As I see it, you made multiple observations over a period of time following the introduction of the treatments into the single field.  Your analysis should consider some form of "time series" analysis and more than likely requires the use of regression.   While you do have some form of statistical repetition as outlined in the methods, I am shocked that a group of authors would attempt to pass this type of research from a single location.  You have no repeats of the research (the treatments themselves) in either space or time.  Most researchers would have done this in multiple fields and considered the effect over time of the treatments.  What you've submitted, is a minimal background study that needs to be continued one more year and repeated in at least (and based on my training and degree programs nothing less than two additional locations......scientists should almost always consider doing things in threes as two points (or in this case two years) would make it easy to draw a straight line....a third year should introduce some better results/information in this type of monitoring study).

Author Response

Author’s answer to the referee 2.

Manuscript Sustainability-1135402 entitled “Locally available organic waste for counteracting strawberry decline in a mountain specialized cropping area”

Thank you very for further comments; I believe some critical points highlighted by the referee in this study are due to a misunderstanding on the real objectives of the work.

Let me try to clarify some of the issue highlighted by the reviewer.

• As far as the following reviewer’s comment “You did a single treatment on a single field and observed the effects of those treatments over a two year period comments…. you do not have any repeatability of the research…...”,

The experimental setting of this study did not aimed at evaluating whether digestates were effective as soil amendments for improving strawberry crop yield, this is a typical goal of extension services that requires test fields in more sites to even a different experimental scheme than that adopted here. Instead, this study aimed at  investigating the potential that digestates have as residual organic masses in interfering with the microbial components of soils and improving the natural ability of soils to contain the impact of root pathogens. Therefore, since the microbial composition of the soil (bacteria above all) is highly site-dependent, an experimental field with a previous strawberry monoculture and good microbial activity has been specifically searched for this study.

Furthermore, the choice of such experimental site was linked to  possibility of using organic waste from environmentally virtuous activities in that mountain region such as re-use of liquid manure deriving from local livestock activities and urban organic waste recycling in small towns.

• As far as concerns the last comment of the first paraph, “you do not have any repeatability of the research”

The experimental design has three replicates per treatment, each represented by a doble strawberry row with 150 plants each which were assessed for two years which were separately analysed.

• As far as the following comment of the referee: “As I see it, you made multiple observations over a period of time following the introduction of the treatments into the single field. Your analysis should consider some form of "time series" analysis and more than likely requires the use of regression”.

I refer to what I observed above on the objective of this test. We evaluated the overall strawberry production because our goal was to correlate vegetative and productive strawberry parameters with quantity in soil of one of the most important fungal root pathogens and with that of the bacterial communities which can act as growth promoters or be active in root protection.

We are aware that the data of our test cannot be of great interest for  plant physiologists which are more focused on strawberry crop response to pre-transplant treatment with digestates nor to the extension services which are more interested in clear indications for farmers on the use of digestates as soil amendments.  

On the other hand, this work focused on the response of soil borne pathogens and soil bacterial communities because decades of field trials on the use of digestates as soil amendments which were based solely on yield response, have not been able to provide a clear response on the utility of those materials due to the largely variable crop yield response. The latter issue was mentioned in introduction and specifically quoted in conclusion where it was supported by reference just for make more robust the objective of our study.