Radiation Use Efficiency and Agronomic Performance of Biomass Sorghum under Different Sowing Dates

Round 1

Reviewer 1 Report

I have reviewed the manuscript entitled: Radiation Use Efficiency and Agronomic Performance of Biomass Sorghum under Different Sowing Dates. In my opinion, the manuscript needs minor revision. My comments are listed below.

1.

 I have the biggest reservations about the use of non-uniform terminology. The terms used should be uniform throughout the text. In addition, the abbreviation should be introduced with the first use of the term and then, the abbreviation only should be use.

- line 90 “dry biomass” – it is not clear if is it about dry biomass yield or dry biomass content in fresh biomass. I suppose that it should be dry biomass yield. But, later in the text, the Authors use the term “dry plant weight” (line 140) or “dry biomass productivity” (line 254) when they were writing about biomass yield.

Moreover, in the line 144, term of “dry biomass” was used as a term for dry matter content in biomass.

In my opinion it has to be clarified what dry biomass the Authors have in mind. The term “dry biomass” itself is insufficient.

Please, uniform this terminology because it is confusing. I suggest to use term “dry biomass yield” or
“dry biomass productivity” and abbreviation “DB” from the beginning of the text, when you are writing about the biomass yield. When you are writing about dry matter content in biomass, I suggest term of “dry matter content” (line 144).

-lines 91-93 - This sentence should be rewritten. It is not correct formulation “performance of three biomass sorghum hybrid” and “economic feasibility of three biomass..”. Rather, should be  performance/economic feasibility of cultivation/production of biomass”.

Moreover, did you mean “biomass sorghum hybrids” or rather “sorghum hybrid biomass”. In my opinion it should be “sorghum biomass growth” not “biomass sorghum growth”.

3.

-line 91 – ‘several sowing dates’ – Why not write more specifically:  ‘three sowing dates’

4.

-line 217 – “the relationship of CGR to daily IPAR” not “….on daily IPAR”.

5.

-line 228 – It is not clear, how “frequency and quantity of irrigation water applied” influence on variation in the cost of production, since the same, “full irrigation was applied to all experimental plot” (line 119). Is it simply related to the difference in water demand between hybrids?

6.

-line 254 - please use an abbreviation if you entered one before

7.

-lines 254 – 257 and lines 290-293 – Please, write ‘…., respectively.’ at the end of the sentence, as you have done correctly in the lines 399 – 401.  For example: Dry biomass productivity ranged across hybrids and years from 20.5 to 35.7, 23.1 to 254 35.0, and 19.2 to 32.4 Mg ha-1, for the early, mid, and late sowing season, respectively.

8.

Lines 325 – 326 – This sentence should be rewritten. I suggest, better will be: The results showed that only for the pair of the hybrids: Blade ES 5140 and Blade ES 5200 there are no statistical difference (p = 0.666).

9.

Line 340 – repeated ‘during the’

10.

Lines 348 – 351 – This sentence should be reworded. It would be better to write: At sampling times,  average CGR per sowing season was 29.0, 26.4, and 19.9 g m-2 d-1 for early-, mid-, and late season, respectively. While, average CGR per hybrid was 22.3, 24.1, and 28.9 g m-2 d-1 for 350 Pioneer 977F, Blade ES 5140, and Blade ES 5200, respectively.

Lines 364-365 – ‘higher’, ‘lower’ than what? , rather simply ‘the highest’.

11.

Lines 398 -399 – “Higher revenues were associated with higher biomass yields…”

This sentence it is only partially true, for the Blade ES 5140 hybrids, which exhibited the highest revenue at the early sowing season and also reached  the highest biomass yield at the early sowing season. Two other hybrids exhibited the highest revenues at late sowing season, when their yields were the lowest. In my opinion, high revenue is depended, first of all, on the highest biomass price at the late harvest. The differences in biomass yield between sowing seasons are so small that they have almost no effect, with such differences in the biomass price. This should be clearly stated in the text.

12.

Lines 412 – 414 – This sentence (Conversely, the highest average costs of production were obtained when sowing late for all hybrids) seems to be contrary to the sentence in line 407 (Overall lower costs of production were estimated for all hybrids in late sowing dates). I understand that in one sentence is about production per hectare and the other is about production per unit of mass, but it is not so clear when reading this. I think that the term ‘average costs of production’ is not correct and it says nothing about the fact that it concerns a unit of mass. I came to this only after analyzing the table 3. I suggest changing the terminology (also in the Table 3): ‘production cost per unit of area’ and ‘production per unit of mass’.

13.

Please, pay attention to the correct citations in the text. For example:

Line 438 - Meki, Ogoshi [26] should be Meki et al.[26] according to the References list.

Line 448 –‘reported by [5]’, should be reported by Rinaldi and Garofalo [5], etc.

14.

Lines 449- 450 – Not ’but less from those reported from, [29] and [30]…’ but rather: ’but less than those reported by Ceotto et al. [29] and Olson et al. [30], who in similar experiment obtained higher LAI value ranged from…’.

Lines 527-528  - the same remark as in the item 11.

16.

Line 540 – the same remark as in the item 2. Sorghum biomass? , rather than “biomass sorghum”.

Do you relly mean ‘sorghum for biomass’ = biomass sorghum.

In this context, it is rather about ‘ ‘biomass of sorghum’, so,  in my opinion, it should be ‘sorghum biomass’.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The MS showed comparisons of the canopy light interception and RUE of sorghum sown early, mid and late in the season. Rue is useful estimates of the crop growth and development for yield estimation.

I have 2 observations: 

a. The crop was sown at 1.02m distance in rows which might have shown higher transmittance in early growth and development of the crop. If so then how the canopy showed light interception values 92-95%?

b. What are the difference between Fig. 5 and Fig. 6? to be both looks the RUE with a different approach.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

The article actually has a balance sheet and the totals are presented as bar charts. Little has been written about energy efficiency, for example. This is important in order to lay the foundations for research on energy efficiency. This shows how the emission of emission gases is balanced. I recommend that the authors read the article https://doi.org/10.3390/en14175574

There is no in-depth statistical analysis. Statistical analysis was not sufficiently discussed. The entire manuscript looks like an excerpt from a report from some major work. Without statistics and research, the article does not contribute to any knowledge development. An expansion of literature, conclusions and discussions is required.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf