Effects of Legume–Grass Ratio on C and Nutrients of Root and Soil in Common Vetch–Oat Mixture under Fertilization

Round 1

Reviewer 1 Report

In the chapter "Materials and Methods", the Authors provide the sowing amount of oats and common vetch seeds in kg / ha and the numerical ratio of 1:0,  2:1 , 1:2 , 0:1. These numbers do not coincide with the reported sowing amount, which is probably due to the different nature of common vetch and oat seeds. Therefore, it would be good for the Authors to complete the information on the percentage share of both plant species, e.g.

2:1  (VA21) - 62.5% common vetch + 37.5% oats

1:2  (VA 12) - 30% common vetch + 70% oats

1:0  (V) - 100%  common vetch

0:1 (A) – 100% oats

Line 190 - (Fig 1 - b), it should be (Fig - 1a)

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

GENERAL COMMENTS

The manuscript entitled “Effects of legume-grass ratio on C and nutrients of root and soil in common vetch-oat mixture under fertilization” concerns field experiments with the aim of evaluating the effects of different vetch/oat mixtures under various N/P fertilization regimes on C, N and P of roots and soil.

The subject of the manuscript falls with the general scope of the Journal and provides interesting data. The most important gap, in my opinion, is due to the duration of the experiment. Only one year for the N test and N+P test, respectively, is not enough for agronomic trials. I strongly invite authors to consider at least two years for both of them, if any. On the contrary, the mixing ratio factor was repeated for two years.

Below other general comments and suggestions:

·         M&Ms lack of several important information (see specific comments)

·         The English language and grammar need to be checked by a mother-tongue proof-reader

·         The number of references is too high for a research paper

TITLE: appropriate.

KEYWORDS: I suggest changing “fertilizer application” to “fertilization”, and adding “intercropping”.                                                                                                                        

ABSTRACT: It properly summarises the manuscript. However, the aims could be better explained and, mostly, the main findings should be highlighted by adding values in brackets.

INTRODUCTION: the overall organization of this section is good, since it provides an appropriate background for readers. My only comment is related to references: 41 references is too much for just the introduction in a research paper. I therefore suggest reducing the number of references, for instance by deleting some multiple references in several sentences.

Nevertheless, several references are quite outdated and could be changed with more updated ones. For example, this recent review (Scavo et al., 2019. https://doi.org/10.1007/s11104-019-04190-y) could be of interest either here or in the discussion to analyse the interrelationships between plant exudates and soil characteristics. 

M&M: This section is the most problematic, because in its present form is incomplete.

See specific comments:

·         line 98: was

·         line 99: please add a Figure or Table with the climatic trend of the experimental field during 2019 and 2020: monthly rainfall, monthly average maximum air temperature, monthly average minimum air temperature

·         lines 102-106: please add soil pH, organic matter content and cation exchange capacity prior to the experiment. These parameters have a strong influence on the studied variables

·         please move lines 112-114 at the start of the paragraph

·         Why did you carry out the N test and the N+P test for just one year, respectively? Both experiments have should be repeated for at least two years to gain strong data. This is an important deficiency

·         Please add a paragraph between 2.2 and 2.3 with the agronomic management, which is not reported. Which kind of tillage was applied and when? Any irrigation? If yes, how and in which amount? Any weed control? If yes, how?

·         Line 128: please specify the time of vetch flowering stage

·         Please add the length of the biological cycle of both common vetch and oat

·         Line 129: measurements

·         Lines 129-131: please specify better the soil sampling methodology? How samples were collected for each plot and in total? Was a soil core the sum of subsamples or not? Were soil samples collected randomly or along the diagonals or what?

·         Statistical analysis: were the basic assumptions of ANOVA satisfied before analysis (homoscedasticity and normality)? None information. If yes, how? Please specify

·         Which test and at what probably level was used for means multiple comparisons?

RESULTS: they were properly reported. Also, discussions and conclusions are appropriate.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors addressed all my comments and suggestions, thus improving the overall quality of the manuscript. I still repeat my concerns about the duration of the experiment. I understand the difficulties in funding but strong agronomic trials need medium-long term field experiments. Therefore, I invite authors and editor to highlight that the present research shows interesting but preliminary data.