What Factors Control the Crude Protein Content Variation of a Basaltic “Campos” Native Grassland of South America?
, Martín Durante 1,3, José María Arroyo 4, Fiorella Cazzuli 1, Carolina Bremm 5 and Martín Jaurena 1,*
Round 1
Reviewer 1 Report
The paper to explore the main drivers that influence forage crude protein content in a basaltic NG sward of Uruguay and to determine the intermediate pathways that operate at different scales through a structural model.
The topic and the followed approach are quite interesting. From a formal point of view, the paper is well written.
However, the manuscript is not suitable for publication in the present form.
Unfortunately, there are two main weak points.
Firstly
MM section 2.2. L 118 – 138 according to the description given is really hard, for a general readership, to repeat the experiment.
First of all, if, at L 114 target sward height of 10 cm was reached, then it is unclear how …at L 124 .. total of 20 patches of 4, 8, 12 and 16 cm forage were chosen ….
How were 20 patches of 4, 8, 12 and 16 cm forage obtained? Please, explain it.
L 128 Each patch was then cut into 4 cm strata, obtaining 1, 2, 3 and 4 strata from the patches of 4, 8, 12 and 16 cm, respectively…
What does 4 cm mean? Which is the cutting height for 4 cm stratum? Do you mean the forage harvested up to 4 cm from ground level or the forage harvested after cutting above 4 cm?
To avoid misunderstanding it is preferable to indicate the cutting height for each stratum or strata cm stratum. Which are the total number of samples obtained by clipping/cutting?
Please, explain and modify to give a univocal information to allow others to replicate.
My suggestion is authors prepare a diagram or a graph giving the abovementioned details for improving the readability of methodological details.
Secondly
As the herbage mass of each forage patch was estimated (L 126),
the results expressed as protein yields per hectare might be added giving a basic quantitative information, which is complementary to that of the main pathways explaining the variation in the grassland forage crude protein content.
Therefore, authors are kindly requested to consider this possible piece of information.
Author Response
Dear Reviewer
Thank you very much for the suggestions to improve the paper.
R1: MM section 2.2. L 115 – 133 according to the description given is really hard, for a general readership, to repeat the experiment.
A: Since the experiment is run on an ongoing long-term experiment, it poses an extra hard situation to repeat the experiment, even though it would be still possible to replicate. Nevertheless, with the adjustments we did in the text in the MM section, we hope that the overall protocol may be better understood to render the experiment potentially replicable.
R1: First of all, if, at L 114 target sward height of 10 cm was reached, then it is unclear how …at L 124 .. total of 20 patches of 4, 8, 12 and 16 cm forage were chosen ….
A: The target sward height is 10 cm on average. Because native rangelands are highly heterogeneous in many ways (species composition for instance), this also has an impact on sward height. Thus, even though the average sward height is 10 cm, it is still possible to find patches of 4, 8, 12 and 16 cm. To make this issue more easily understood, we specified all this further on lines 115-117.
R1: How were 20 patches of 4, 8, 12 and 16 cm forage obtained? Please, explain it.
A: Accepted. The explanation of this part of the procedure was clarified between lines 120-135 and figure 1.
R1: What does 4 cm mean? Which is the cutting height for 4 cm stratum? Do you mean the forage harvested up to 4 cm from ground level or the forage harvested after cutting above 4 cm?
To avoid misunderstanding it is preferable to indicate the cutting height for each stratum or strata cm stratum. Which are the total number of samples obtained by clipping/cutting?
R1. Please, explain and modify to give a univocal information to allow others to replicate.
A: Accepted. The explanation of this part of the procedure was clarified between lines 120-135.
R1: My suggestion is authors prepare a diagram or a graph giving the abovementioned details for improving the readability of methodological details.
A: Accepted. Besides a clarified written explanation as mentioned above, we present a diagram (Fig 1).
R1: As the herbage mass of each forage patch was estimated (L 126), the results expressed as protein yields per hectare might be added giving a basic quantitative information, which is complementary to that of the main pathways explaining the variation in the grassland forage crude protein content.
A: Each patch´s DM biomass was estimated using a precision scale. With the protocol we used, we could estimate the PC content of each stratum or each patch. Unfortunately, since we lack the data on the frequency of each patch within each plot, we are unable to estimate total PC per hectare.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear authors,
The article entitled 'What factors control the crude protein content variation of a Basaltic “Campos” native grassland of South America?' submitted to the section of Grassland and Pasture Science is addressing an interesting topic of research for being published at Agronomy MDPI. See below a few comments/suggestions to be answered/applied for improving its quality:
- Use scientific nomenclature to name each of the species indicated in lines L182, L184, L185, L188, L190, L192, L193 and Figure 1.
- Check standard errors in Figure 2 and Figure 3.
- Reformulate the sentence in lines L225 and L226.
- Add acronym SWA in L232.
- Delete " in lines L365 and L366.
- Replace 'awarder' by 'awarded' in L366.
- Replace 'in' by 'to' in L371.
Best regards,
Reviewer.
Author Response
Dear Reviewer
Thank you very much for the suggestions to improve the paper.
R2: Use scientific nomenclature to name each of the species indicated in lines L182, L184, L185, L188, L190, L192, L193 and Figure 1.
A: Accepted. Figure 1 was modified accordingly.
Lolium multiflorum Lam., Paspalum notatum Flüggé, Paspalum plicatulum Michx., Sporobolus indicus (L.) R. Br., Andropogon ternatus (Spreng.) Nees
R2: Check standard errors in Figure 2 and Figure 3.
A: Accepted. Figures 2 and 3 were modified accordingly
R2: Reformulate the sentence in lines L225 and L226.
A: Before “Meanwhile, during the wet summer without a SWA restriction, FCPC was 2.5% greater than that of the dry summer (Figure 4). ” After “During the wet summer, FCPC was 2.5% greater compared to the dry summer.” Lines 255-257.
R2: Add acronym SWA in L232.
A: Accepted.
R2: Delete " in lines L365 and L366.
A: Accepted
R2: Replace 'awarder' by 'awarded' in L366.
A: The text was modified according to suggestions.
Replace 'in' by 'to' in L371.
A: Accepted
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
In the revised version, important methodological details have been clearly explained and well represented. Paper has been substantially improved.
