Spatial Distribution of Nutrient Loads Based on Mineral Fertilizers Applied to Crops: Case Study of the Lobo Basin in Côte d’Ivoire (West Africa)

Round 1

Reviewer 1 Report

The MS has a title of

Estimation of nutrient loads in an agricultural area: Case study of the Lobo Basin in Côte d'Ivoire (West Africa)

1- The general comment:

Some published articles on this topic, and this area as below:

-          Jean Olivier, K.K.; Brou, D.; Jules, M.o.M.; Georges, E.S.; Frédéric, P.; Didier, G. Estimation of Groundwater Recharge in the Lobo Catchment (Central-Western Region of Côte d’Ivoire). Hydrology 2022, 9, 23. https://doi.org/10.3390/ hydrology902002

-          Koua, T.J.-J.; Dhanesh, Y.; Jeong, J., Srinivasan, R.; Anoh, K.A. Implementation of the Semi-Distributed SWAT (Soil and Water 710 Assessment Tool) Model Capacity in the Lobo Watershed at Nibéhibé (Center-West of Côte D’Ivoire). Journal of Geoscience and 711 Environment Protection, 2021, 9, 21-38.

 

2- The title needs to be informative and attractive, try to change the “an agricultural area”?

3- try to avoid using abbreviations in abstract like NSE and PBIAS???

4- Keywords, dot not use any word already mentioned in the title, please

5- Introduction section

Please update the refs. Try to use several ref. In 2023 and 2022 and 2021!

I did Not find any recent ref. and all are very old and not accepted for sure!

In the entire MS, I found only 1 ref. (2022) from total 70, and during the last 5 years, nothing???

Try to add a paragraph on eutrophication as main topic in your MS

6- Materials section: the author mentioned

“These data are available in the FAO database [15] and have been completed by physicochemical properties obtained after field sampling and in-laboratory analyses. The dominant soil of the basin is the sandy-clay-loam about 38%, followed by the sandy-loam soil (32%) of the basin.”

Which parameter, and where these nutrients and their measuring and which methods used? All these are absent?? And water samples as well!

7- Figure 2 please each one (A----, D) should be large to be seeable

8- Please write in correct form not (Kg/Ha) but as “kg ha^-1” mg/L to mg L^-1, in all MS

9- Discussion: the authors mentioned that

“The observed flow data used for this study are mostly available for the period 1981-1994.”

Where is your study from the current period?????

Did the studied area change by time from this period?

Major revision is needed

 

it is ok

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper is an interesting study on the nutrient (N and P) loads in the Lobo watershed (Côte d'Ivoire, West Africa) to understand the spatio-temporal impacts of land management practices on eutrophication. The methodology uses two steps: streamflow calibration and nutrient (N and P) estimation using the Soil and Water Assessment Tool (SWAT) watershed model.

The manuscript’s strengths are the identification of the nutrient loads from agricultural practices in the Lobo watershed, a very vast area (6,442.66 km²), to understand the spatio-temporal evolution of nutrient transport processes using the SWAT model. The assessment is based on the amounts of fertilizer applied to crops.

 The weaknesses are that these SWAT model predictions are difficult to apply when climatic changes are occurring globally.

Title - adequate

 Abstract – the information given is adequate and concise.

 1.Introduction – The aim of paper is adequately exploited.

 2. Materials and Methods

2.1 Study area – Well characterized, well illustrated by Fig. 1, but the graphic quality of this figure should be improved (Africa map).

Correct line 95

 2.1.2 Data – Well organized.

Lines 153-154 – correct sentence

 2.2. Methods – adequate and detailed description of the methods used.

You should justify better your option for SUFI 2, was just the fact of its simplicity ? (lines 230/231)

 Line 298 – Correct sentence.          

Lines 329/330 - are you referring to % m/m? Be clearer.

Lines 335/340 - The chemical form in which nitrogen is present is dependent on the oxygen level, nitrification and denitrification processes may occur, how was these considered? You state that “The amount of nitrate contained in runoff is assessed from the nitrate concentration in moving water. This concentration is a proportion of the nitrate mass in the runoff volume…”, isn´t this very rigid?

Line 361 – Correct sentence.

Line 372 – Correct units to mg sed

Line 375 – correct sentence

Line 384 – Correct units to mg/m3

Line 386 – Correct units to m3/mg

 3. Results– Adequately-organized (but can be improved), well documented by tables and figures.

 Fig 4 B, C and D - correct units kg/Ha

 Improve quality of legend of Figure 5, improve the contrast of colors.

Describe analytical methods used for nitrate and phosphorus determination.

 4. Discussion - Adequate

The eutrophication phenomenon in my opinion should be moved to Introduction.

 5. Conclusions – Adequate but some solution to the eutrophication problem should be suggested.

 The paper is suitable for publication with minor revisions.

Adequate

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

many thanks for your corrections

ok, thanks

Author Response

Dear reviewer,
We are satisfied with your review. In round 1, we tried to take your suggestions into account point by point. We dare to believe that you have been satisfied. For round 2, we also tried to satisfy your opinion. So we tried to improve the different parts highlighted in yellow.

Thank you so much.