The Delayed Effect of Low-Energy Lignite Organic Matter on the Treatment Optimization of Zea mays L. Grown for Silage

Round 1

Reviewer 1 Report

The work fits the journal scope. It contains many experimental data, and the analyses are performed with the highest technical standards. But the results are not represented and interpreted appropriately. Data presented in several tables are not clearly grouped, so the results cannot be understood properly. The evidence concerning the influence of lignite organic matter on plant yield (as stated to be the main aim of the work) is not entirely conclusive.

Elements to improve and to clarify in the manuscript:

- row 14: the notation of control with “0” should be omitted, because it becomes confusing when enumerating the experimental variants, where control is number “1” instead of “0”

- rows 14-15: for one who reads only the abstract to decide if the article is of interest, it is not clear what do N1, N2 and N3 represent

- row 14: when affirming that “nitrogen was applied as fertilizer objects 3, 4 and 5”, please specify what is the chemical form of this nitrogen, and what is the difference from the N existing in “object no. 2”

- row 25: please mention the “analyzed parameters” which were significantly improved by addition of lignite organic matter, because the affirmation is too general

- row 26: please reconsider the inclusion of the term “follow-up” among the key-words, because it is a very general term, not strictly related to the topic of research

-row 68: please explain briefly what “physiological efficiency” means in the given context for the authors (even if its calculation is given in the methods section), because it is a very generic term for the reader, “physiology” comprising a miriad of vital processes and related phenomena; please also underline briefly the essence of the difference between agronomic efficiency and physiological efficiency

- row 82: please mention the chemical compounds that built up the “NPKMgS” fertilizers, to see the forms of N, P, K, Mg and S supply

- row 85: please formulate more clearly: the forecrop and the studied main crop were both maize grown for silage, in two consecutive series?

- row 114: please specify how is yield expressed

- rows 158-160: a part of the text repeats itself, please rephrase

- row 167: please specify if the fresh matter yield comprises the root system of the plant, or it refers only to the aboveground shoots

- table 3, last row: what is the scientific reason of calculating the average fresh matter yield of all the experimental variants taken together? What would it reflect?

- table 3: if the three cultivars and the three years of cultivation are represented in separate columns, how would the reader know what are the yields of each cultivar for each year? It is not clear which are the yields obtained with the two different amounts of organomineral fertilizer resulted from lignite.

- row 197: what does the abbreviation DM represent? If it means dry mass, please mention in the section of methods how was it determined

- rows 202-203: please try to clarify the affirmation that “of all nutrients, nitrogen increases crop yields to the greatest extent”; according to our present knowledge in plant physiology, this is not an accurate statement, because generally plant yield is limited by the least available essential mineral nutrient as compared to the optimal quantity under the given developmental condition (see Liebig’s law), and apart from nitrogen there are more than ten other essential mineral nutrients, none of the being more important than the others

- table 4: it is not clear which values of N, P, K, Mg and S content belong to which cultivar and in which year; e. g.: how would we know the N content of Silien cultivar in 2014? The same observation is also valid for tables 5, 6 and 7

-rows 209-211: please try to clarify how can one explain that P content is lower in plants treated with a fertilizer containing P, than in control plants that did not receive fertilizers. If so, what is the reason of applying fertilizers? How should one correctly interpret these results?

-row 228: please give further information to understand the “dilution of K in a larger yield”. Isn’t a higher biomass a larger sink for mineral nutrients?

- row 234: please clarify the affirmation that “according to other publications, K content of silage maize is at an optimal level”: optimal for what, and from what point of view?

- row 236-239: please try to explain briefly the finding that Mg content is correlated with yield, but it is the highest in control plants which did not receive fertilizers and had lower yield. This finding seems to contain two contradictory parts.

- rows 248-249: please try to find a reasonable explanation for the results that show that the mineral element content of maize plants grown under similar nutritional conditions would be significantly different in subsequent years

- rows 286-288: please try to explain why was leaching of S more intense in 2014 than in 2015 and 2016

- rows 336-337: please clarify why mineral N supplies would reduce the physiological efficiency of N

- rows 378-384: please comment, from an agronomical point of view, the positive and negative correlations found between the AE and PE of different mineral macronutrients, because in the present form the message of these conclusions may not be clear enough for the readers.

 

Author Response

The work fits the journal scope. It contains many experimental data, and the analyses are performed with the highest technical standards. But the results are not represented and interpreted appropriately. Data presented in several tables are not clearly grouped, so the results cannot be understood properly. The evidence concerning the influence of lignite organic matter on plant yield (as stated to be the main aim of the work) is not entirely conclusive.

 

Thank you for your review.

After carefully reading the comments and suggestions of the Reviewer kindly inform that the manuscript has been revised taking into account the legitimate Reviewer’s comments.

 

Elements to improve and to clarify in the manuscript:

- row 14: the notation of control with “0” should be omitted, because it becomes confusing when enumerating the experimental variants, where control is number “1” instead of “0”

BS response: Thank you very much for this attention. In the attached file, the control entry "0" has been removed.

- rows 14-15: for one who reads only the abstract to decide if the article is of interest, it is not clear what do N1, N2 and N3 represent

BS response: Next to symbols N1, N2 and N3 a numerical record of nitrogen doses has been added.

- row 14: when affirming that “nitrogen was applied as fertilizer objects 3, 4 and 5”, please specify what is the chemical form of this nitrogen, and what is the difference from the N existing in “object no. 2”

BS response: Nitrogen N1, N2 and N3 was used as top dressing in the form of urea, and nitrogen used in polyfoska®M-MAKS (NPKMgS) was in the form of ammonium phosphate 1 and 2.

- row 25: please mention the “analyzed parameters” which were significantly improved by addition of lignite organic matter, because the affirmation is too general

BS response: The low-energy lignite used for the forecrop in the doses 1t and 5t at the NPKMgS + N1 and NPKMgS + N2 increased the yield of maize; uptake with N, P, K, Mg and S yield and agronomic efficiency of N, P, K, Mg and S.

- row 26: please reconsider the inclusion of the term “follow-up” among the key-words, because it is a very general term, not strictly related to the topic of research

BS response: Thank you very much for attention. Follow-up - has been removed.

-row 68: please explain briefly what “physiological efficiency” means in the given context for the authors (even if its calculation is given in the methods section), because it is a very generic term for the reader, “physiology” comprising a miriad of vital processes and related phenomena; please also underline briefly the essence of the difference between agronomic efficiency and physiological efficiency

BS response: In agronomy, we calculate agronomic and phosiological effectiveness according to specific formulas. The uptake of nutrients is certainly influenced by plant physiological processes, ion antagonism and synergism, etc. When calculating agronomic effectiveness, yield increases are related to the dose of the component used, and with the physiological effectiveness to the uptake of the component.

- row 82: please mention the chemical compounds that built up the “NPKMgS” fertilizers, to see the forms of N, P, K, Mg and S supply

BS response: Polyfoska®M-MAKS (NPKMgS) – chemical compounds: NH₄H₂PO₄, (NH₄)₂HPO₄, KCl, MgCO₃ and K₂SO₄. (attached file)

- row 85: please formulate more clearly: the forecrop and the studied main crop were both maize grown for silage, in two consecutive series?

BS response: In the three consecutive years of research, the test plant was maize grown for silage. The forecrop was also maize grown for silage. (attached file)

- row 114: please specify how is yield expressed

BS response: The maize yield was expressed in kg ha^-1.

- rows 158-160: a part of the text repeats itself, please rephrase

BS response: „It contained moderate amounts of absorbable forms of phosphorus, potassium and magnesium” – removed.

- row 167: please specify if the fresh matter yield comprises the root system of the plant, or it refers only to the aboveground shoots

BS response: Of course, silage maize includes the above-ground part of the plant.

- table 3, last row: what is the scientific reason of calculating the average fresh matter yield of all the experimental variants taken together? What would it reflect?

BS response: The last row and last column show the average maize yield for the levels of the test factors.

- table 3: if the three cultivars and the three years of cultivation are represented in separate columns, how would the reader know what are the yields of each cultivar for each year? It is not clear which are the yields obtained with the two different amounts of organomineral fertilizer resulted from lignite.

BS response: Table 3 shows the average yields of maize grown for silage. The yields shown for the varieties are the average for 3 years. The yields in the following years of research are the average for the varieties. In row 3 and 4 the yield of maize is presented, where 1t and 5t organomineral fertilizer were used under the forecrop, respectively.

- row 197: what does the abbreviation DM represent? If it means dry mass, please mention in the section of methods how was it determined

BS response: A dry matter (DM) determination has been added to the Materials and Methods section.

- rows 202-203: please try to clarify the affirmation that “of all nutrients, nitrogen increases crop yields to the greatest extent”; according to our present knowledge in plant physiology, this is not an accurate statement, because generally plant yield is limited by the least available essential mineral nutrient as compared to the optimal quantity under the given developmental condition (see Liebig’s law), and apart from nitrogen there are more than ten other essential mineral nutrients, none of the being more important than the others

BS response: „Of all nutrients, nitrogen increases crop yields to the greatest extent” – according to Rutkowska et al. [46]. This statement applies to the fertilization of maize grown for silage. According to the authors of the manuscript, this is true for this plant.  

- table 4: it is not clear which values of N, P, K, Mg and S content belong to which cultivar and in which year; e. g.: how would we know the N content of Silien cultivar in 2014? The same observation is also valid for tables 5, 6 and 7

BS response: Tables 4, 5, 6 and 7 show the means for individual research factors.

-rows 209-211: please try to clarify how can one explain that P content is lower in plants treated with a fertilizer containing P, than in control plants that did not receive fertilizers. If so, what is the reason of applying fertilizers? How should one correctly interpret these results?

BS response: That was a result of the dilution of this chemical element in higher yields of maize, which was confirmed by other research [14].

-row 228: please give further information to understand the “dilution of K in a larger yield”. Isn’t a higher biomass a larger sink for mineral nutrients?

BS response: Fertilization studies in which plants are grown green show a reduction in the nutrient content with high yields. Hence the term "dilution" was introduced.

- row 234: please clarify the affirmation that “according to other publications, K content of silage maize is at an optimal level”: optimal for what, and from what point of view?

BS response: According to other publications, potassium content of silage maize is a tan optimal level [30], for forage plants [51]. (attached file)

- row 236-239: please try to explain briefly the finding that Mg content is correlated with yield, but it is the highest in control plants which did not receive fertilizers and had lower yield. This finding seems to contain two contradictory parts.

BS response: The magnesium content of maize dry matter was significantly negatively correlated with potassium content and the fresh matter yield (Figure 3b). (attached file)

- rows 248-249: please try to find a reasonable explanation for the results that show that the mineral element content of maize plants grown under similar nutritional conditions would be significantly different in subsequent years

BS response: The main reason for the lower sulfur content in the biomass of maize harvested in 2014 may have been unfavorable meteological conditions during the growing season. Studies by other authors indicate the same reasons [54, 55].

- rows 286-288: please try to explain why was leaching of S more intense in 2014 than in 2015 and 2016

BS response: A significantly low uptake of sulphur in 2014 was mainly a result of low yields. (attached file)

- rows 336-337: please clarify why mineral N supplies would reduce the physiological efficiency of N

BS response: The decrease in the physiological efficiency of nitrogen was the result of a significantly higher nitrogen uptake with the yield of maize fertilized with NPKMgS + N1, NPKMgS + N2 and NPKMgS in relation to nitrogen uptake from the control object.

- rows 378-384: please comment, from an agronomical point of view, the positive and negative correlations found between the AE and PE of different mineral macronutrients, because in the present form the message of these conclusions may not be clear enough for the readers.

BS response: From the agronomic point of view, positive correlations between the agronomic efficiency of N, P, K, Mg and S and the physiological efficiency of N, P, K, Mg and S are the most favorable. Under natural, field conditions, this is impossible to achieve because of the  biochemical processes in plants.

 

Best Regards

Authors

Reviewer 2 Report

Present study is explains the fate of lignite compost in maize, written nicely, however, it needs some clarifications as below;

-Rewrite abstract with a few lines about significance of study in start, treatments and also describe results with numerical values. Conclude at the end in a few scentences.

-Nutrient composition of  organomineral fertilizer based on lignite waste produced by the company INCO (Warsaw-Poland) should be presented in a separate table.

-Better to add economic analysis to answer whether application of lignite waste has potential as supplement of the mineral fertilizers?

-more extensive discussion needed.

-there are spelling mistakes, need corrections.

-conclusion should be in few lines.

Author Response

Thank you for your review.

After carefully reading the comments and suggestions of the Reviewer kindly inform that the manuscript has been revised taking into account the legitimate Reviewer’s comments.

 

Present study is explains the fate of lignite compost in maize, written nicely, however, it needs some clarifications as below;

-Rewrite abstract with a few lines about significance of study in start, treatments and also describe results with numerical values. Conclude at the end in a few scentences.

BS response: The abstract was supplemented as suggested by the Reviewer. (attached file)

-Nutrient composition of  organomineral fertilizer based on lignite waste produced by the company INCO (Warsaw-Poland) should be presented in a separate table.

BS response: We cannot provide the chemical composition of an organomineral fertilizer produced on the basis of waste lignite. The fertilizer is at the stage of granting a patent.

-Better to add economic analysis to answer whether application of lignite waste has potential as supplement of the mineral fertilizers?

BS response: The economic analysis of the use of an organomineral fertilizer was not the aim of the research. It was not about supplementing fertilizer ingredients, but increasing the use of ingredients used in mineral fertilizers thanks to the organic matter introduced into the soil.

-more extensive discussion needed.

BS response: The discussion of the results has been extended to include important references. (attached file)

-there are spelling mistakes, need corrections.

BS response: Spelling errors have been corrected throughout the manuscript.

-conclusion should be in few lines.

BS response: Conclusions were shortened as suggested by the Reviewer.

Best Regards

Authors

Reviewer 3 Report

Thank you for providing with an opportunity to review Manuscript ID: 1943166 for your prestigious Journal. I have gone through the article and found it interesting and timely which will catch broader readership community. However, there are few things which need author’s attention during revision process.

        Abstract

·         The abstract in present form is difficult to understand, consult some good publication and rephrase the whole section.

·         The abstract must contain background, results, conclusion containing future direction, which is missing in present form.

·         Add one or two sentences regarding conclusion of this study

       Introduction

·         There are lot many grammatical mistakes which are causing bad taste, author need to fix grammatical mistakes.

·         Rephrase the sentence structure and remove passive voice sentences.

·         Add more details about organic matter application and its interaction with different crops.

·         Double check all reference, some looks irrelevant to this study.

·         Line 44-47. Rewrite this sentence and make it clear for readers, specially how you link with previous study

·         Add more details and reference in last part of introduction part.

·         Check carefully and make a story and connection between paragraphs.

Material and Methods

·         Add more details regarding field of your experiment and how your mange to apply treatments, put in details and add references in material and method section

·         Properly mention about your previous study which you linked to present study.

    Results and discussion

·         Why not you go for deep stat analysis.

·         Be consistent with abbreviations, provide the full form at first, abbreviation can be used subsequently.

·         Provide with proper SI unit while quoting results.

·         Add more detail in result and discussion section, specially compare your study with previous studies and compile your results carefully.

 

 

 

 

 

 

 

Author Response

Thank you for providing with an opportunity to review Manuscript ID: 1943166 for your prestigious Journal. I have gone through the article and found it interesting and timely which will catch broader readership community. However, there are few things which need author’s attention during revision process.

Thank you for your review.

After carefully reading the comments and suggestions of the Reviewer kindly inform that the manuscript has been revised taking into account the legitimate Reviewer’s comments.

        Abstract

• The abstract in present form is difficult to understand, consult some good publication and rephrase the whole section.
• The abstract must contain background, results, conclusion containing future direction, which is missing in present form.
• Add one or two sentences regarding conclusion of this study

BS response: The abstract was improved and supplemented as suggested by the Reviewer. (attached file)

       Introduction

• There are lot many grammatical mistakes which are causing bad taste, author need to fix grammatical mistakes.
• Rephrase the sentence structure and remove passive voice sentences.

BS response: Grammatical and stylistic errors have been corrected.

• Add more details about organic matter application and its interaction with different crops.
• Double check all reference, some looks irrelevant to this study.

BS response: Several references have been added on soil organic matter. (attached file)

• Line 44-47. Rewrite this sentence and make it clear for readers, specially how you link with previous study

BS response: The sentence has been corrected.

• Add more details and reference in last part of introduction part.
• Check carefully and make a story and connection between paragraphs.

BS response: Introduction section has been improved with new References.

Material and Methods

• Add more details regarding field of your experiment and how your mange to apply treatments, put in details and add references in material and method section
• Properly mention about your previous study which you linked to present study.

BS response: This section has been supplemented and expanded. (attached file)

    Results and discussion

• Why not you go for deep stat analysis.

BS response: As suggested by the Reviewer, the statistics have been extended. (attached file)

• Be consistent with abbreviations, provide the full form at first, abbreviation can be used subsequently.

BS response: Consistency of full names with abbreviations has been improved.

• Provide with proper SI unit while quoting results.

BS response: The authors tried not to change the cited units.

• Add more detail in result and discussion section, specially compare your study with previous studies and compile your results carefully.

BS response: The discussion of the results has been extended with important references. (attached file)

 

Best Regards

Authors

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I consider that the manuscript has been sufficiently improved to warrant publication in "Agriculture".

Reviewer 2 Report

The present study "The Delayed Effect of Low-Energy Lignite Organic Matter on the Treatment Optimization of Zea mays L. Grown for Silage" is addressing important aspect towards maize production.