Improving Farmers’ Revenue in Crop Rotation Systems with Plot Adjacency Constraints in Organic Farms with Nutrient Amendments

Round 1

Reviewer 1 Report

Dear Authors,

The manuscript with the title "Improving farmers’ revenue in crop rotation systems with plot adjacency constraints in organic farms with nutrient amendments" it is very interesting.

I have only some suggestions and comments.

Line 85: Better say farmer needs instead of “the needs of farmers”

Line 87-93: Please reformulate the objective because I found only a clear affirmation of your objective in the conclusion area. It better to state clear that mineral fertilizers were taken into account when you formulated the models.

Line 101-102: Among which are the soil quality…

Line 113-114: The list of indicators includes different nitrogen forms, organic matter content, soil Ph, the erosion degree and infiltration properties.

Line 124: It provides information about the efficiency level of fertilizer use in terms of quantity absorbed by the crop.

Line 125-126: Please reformulate, it is not clear what do you want to express.

Line 130: residual organic matter

Line 142: Highest yield perhaps, “best yield does not sound…

Figure 1 it makes no sense (it is also repeated in figure 9); you can also write this down like: If the planting area is divided into four plots, we would consider the opposite plots as adjacent.

Line 204: Already read this 3 times since now, please consider something else here

Line 394-395: “The model optimizes 394 the income of farmers while satisfying biophysical, structural, and organizational constraints.” I think this sounds too much, many other aspects must be also taken into consideration to conclude that far in my opinion.

Here is something else. Figure 2 clearly show that you could have a problem with the model. You have  2 plots with 3 month free from cultivation. Why not promote cover crops in that period for sequestration of CO2 and avoid erosion plus some other advantages? We must integrate the new trends in agriculture and sustain them with promoting the benefits in financial income and as well for ecosystem services that they provide.

Author Response

Dear reviewer, thank you very much for your time and valuable comments. Please find a response to each of them below.

The manuscript with the title "Improving farmers’ revenue in crop rotation systems with plot adjacency constraints in organic farms with nutrient amendments" it is very interesting.

I have only some suggestions and comments.

 

Line 85: Better say farmer needs instead of “the needs of farmers”

Done

Line 87-93: Please reformulate the objective because I found only a clear affirmation of your objective in the conclusion area. It better to state clear that mineral fertilizers were taken into account when you formulated the models.

The proposed mathematical model, therefore, aims to identify the best possible crop rotation that will optimize farmers’ incomes while satisfying plot adjacency constraints as well as essential biophysical, structural, and organizational constraints including minimum nutrient requirements.

Line 101-102: Among which are the soil quality…

Done

Line 113-114: The list of indicators includes different nitrogen forms, organic matter content, soil Ph, erosion degree, and infiltration properties.

Done

Line 124: It provides information about the efficiency level of fertilizer use in terms of quantity absorbed by the crop.

Done

Line 125-126: Please reformulate, it is not clear what do you want to express.

We rephrased the sentence. “This can help to prevent nutrient deficiencies that are disastrous for plants.”

Line 130: residual organic matter

Done

Line 142: Highest yield perhaps, “best yield does not sound…

We agree.

Figure 1 it makes no sense (it is also repeated in figure 9); you can also write this down like: If the planting area is divided into four plots, we would consider the opposite plots as adjacent.

We deleted the first figure and accepted your proposition. But Figure 8 (previously 9) introduces an explanation of the Inter Plotting Distance and the consequence on the adjacency constraints. So the last figure is making sense.

Line 204: Already read this 3 times since now, please consider something else here

We kept it like that to ease the understanding of equations.

Line 394-395: “The model optimizes 394 the income of farmers while satisfying biophysical, structural, and organizational constraints.” I think this sounds too much, many other aspects must be also taken into consideration to conclude that far in my opinion.

You are right and we understand your worries. We changed part of the sentence to get the following: “while satisfying essential biophysical, structural, and organizational constraints”. The term “essential” means that we considered the most important constraints.

Here is something else. Figure 2 clearly show that you could have a problem with the model. You have  2 plots with 3 month free from cultivation. Why not promote cover crops in that period for sequestration of CO2 and avoid erosion plus some other advantages? We must integrate the new trends in agriculture and sustain them with promoting the benefits in financial income and as well for ecosystem services that they provide.

Thank you for this remark. As stated in the paper, we used scenarios from the real world to evaluate the model, meaning we tried to get the required values for the optimization. Cover crops are of great importance in sustainable agriculture. But the information we have presently cannot allow us to include them in the optimization model. We consider it as a perspective. We have rewritten the conclusion accordingly.

Reviewer 2 Report

The authors present their analysis that aims to improve the revenue of farmers using crop rotation systems with plot adjacency constraints in organic farms with nutrient amendments. The manuscript in my opinion addresses an interesting question but the writing could be improved to help the reader understand more clearly, the manuscript is hard to follow in parts. Details below:

The abstract is easy to read but would benefit from some pointers to the results gained i.e., from this it is unclear whether the authors were actually successful in achieving what they set out to do. 

This extends across the manuscript but there is no real way to gauge the success of the modelling in the abstract and conclusions, can we quantify and succinctly state the benefit gained e.g. revenue improvement estimated. 

Line 101: among which the soil quality and the agricultural practices --> among which are the soil quality and the agricultural practices

Line 120: define in more details --> define in more detail 

Table 1 and 2 need a little more context, what does this really mean e.g., why choose these crops, are they representative of a diverse range of values?

Line 143: in some conditions of an agro-ecological areas --> grammar check

Lines160-185: while I agree with the constraints that are detailed in this section, I feel it reads quite anecdotally -can we back up any of the points with quantification of their effect from previous work, there are references pointed to but no discussion of this ?

Things like "XAF" stated in text are explained in Tables but the authors should also explain what these terms mean in full in the text upon first mention.

Line 311: However, the sowing period of each crop has been ignored since favorable conditions, mainly the water quantity to grow a particular crop can be provided using an irrigation system.--> perhaps this reasoning could be explained in more detail 

I think more detail is required in the figure legends to explain what the plots show-this would enable them to standalone more, as it is the reader has to flick back and forth between the text as only titles are given to the figures not full legends. The same goes for Tables e.g., Table 8 has "duration (months)" with no reference to what this is the duration of in the legend.

Figures vary significantly in style and colour e.g., some are using black outlines, some grey, some have border outlines/some don't etc could the formatting of the figure be more standardized throughout the text. It also seems like some of the graphs could be combined to make a single figure rather than having so many figures, this could ease comparison between scenarios also.

Line 361: Unfortunately, the GLPK solver again exceeded the time limit without finding a solution. --> what time limit? and why was it selected, I think this should be explained

Author Response

Dear reviewer, thank you very much for your time and valuable comments. Please find a response to each of them below.

The authors present their analysis that aims to improve the revenue of farmers using crop rotation systems with plot adjacency constraints in organic farms with nutrient amendments. The manuscript in my opinion addresses an interesting question but the writing could be improved to help the reader understand more clearly, the manuscript is hard to follow in parts. Details below:

The abstract is easy to read but would benefit from some pointers to the results gained i.e., from this it is unclear whether the authors were actually successful in achieving what they set out to do. 

This extends across the manuscript but there is no real way to gauge the success of the modelling in the abstract and conclusions, can we quantify and succinctly state the benefit gained e.g. revenue improvement estimated. 

The abstract and the conclusion have been modified. The main contribution of this paper is the optimization model. To the best of our knowledge, this is the first formulation of the problem. So, it is difficult to compare it with other work. However, we added some text to appreciate the quality of the solutions and the performance of the solvers.

Line 101: among which the soil quality and the agricultural practices --> among which are the soil quality and the agricultural practices

Done

Line 120: define in more details --> define in more detail 

Done

Table 1 and 2 need a little more context, what does this really mean e.g., why choose these crops, are they representative of a diverse range of values?

Those crops have chosen firstly because they are quite common especially in sub-Saharan where traditional agriculture is mainly practiced, and secondly because we found all the required information to evaluate the proposed model.

Line 143: in some conditions of an agro-ecological areas --> grammar check

Done

Lines160-185: while I agree with the constraints that are detailed in this section, I feel it reads quite anecdotally -can we back up any of the points with quantification of their effect from previous work, there are references pointed to but no discussion of this ?

To the best of our knowledge, such precise quantifications have not yet been performed. However, we added a reference in the introduction showing how the yield can increase due to crop rotation (lines 53 to 55).

Things like "XAF" stated in text are explained in Tables but the authors should also explain what these terms mean in full in the text upon first mention.

XAF is the currencies in central Africa. As stated in the abstract and the introduction, we consider traditional farms. We added an explanation in Table 3 line 209.

Line 311: However, the sowing period of each crop has been ignored since favorable conditions, mainly the water quantity to grow a particular crop can be provided using an irrigation system.--> perhaps this reasoning could be explained in more detail 

Water is one of the important resources for plant growth. Usually, the growing schedule depends on the rainy season. If we can provide sufficient nutrient amendment and an irrigation system, the growing season can be extended out of the rainy season. As testified in the Local Development Support Programme where tomatoes and onions are grown throughout the year thanks to the irrigation system. https://www.irishaid.ie/stories-of-progress/casestudies/archive/2013/september/irrigation-extending-the-growing-season/ 

We added two lines (329 and 330) for a better explanation. 

I think more detail is required in the figure legends to explain what the plots show-this would enable them to standalone more, as it is the reader has to flick back and forth between the text as only titles are given to the figures not full legends. The same goes for Tables e.g., Table 8 has "duration (months)" with no reference to what this is the duration of in the legend.

We added new text in the figure legends to ease the understanding.

Figures vary significantly in style and colour e.g., some are using black outlines, some grey, some have border outlines/some don't etc could the formatting of the figure be more standardized throughout the text. It also seems like some of the graphs could be combined to make a single figure rather than having so many figures, this could ease comparison between scenarios also.

We reworked the figures. However, for better visualization, we preferred not to combine figures.

Line 361: Unfortunately, the GLPK solver again exceeded the time limit without finding a solution. --> what time limit? and why was it selected, I think this should be explained

We added the running times of Cbc and GLPK and the time limit for GLKP in scenarios 2 and 3.

We selected Cbc and GLPK since they are free solvers and they do not require a license compared to Gurobi, Xpress, or Cplex. 

Round 2

Reviewer 2 Report

I am happy that the authors have addressed the comments making the necessary additions to the text.