Short Term Effects of Livestock Manures on Soil Structure Stability, Runoff and Soil Erosion in Semi-Arid Soils under Simulated Rainfall
Round 1
Reviewer 1 Report
A manuscript is devoted to the sort-term effect of manure on soil erodibility and some physical-chemical properties. Two samples of contrast soils differing significantly in texture and organic matter have been examined and two samples of organic amendments have been evaluated. Authors demonstrated an unusual negative effect of both studied organic amendments on soil including decrease in infiltration and increase in surface runoff rates and soil loss. Besides, dramatic increase in EC and SAR of the soils amended with manure have been demonstrated. As an optimization of organic amendments introduction into the soil is of high importance for agricultural practice, I believe this article will be of great interest to a wide range of readers. The manuscript is well written and structured. The data looks convincing and reliable. They are statistically treated and discussed.
However, the manuscript has one critical flaw related to the reality of the situation studied by the authors. Here are a few comments. The samples of organic additives studied by the authors possess noteworthy unfavorable properties. For example, they have a very high electrical conductivity and a high content of sodium and chlorine (10.9-11.3 dS/m, 45-47.5 meq/L and 48.5-50.5 meq/L, respectively) exceeding the commonly given ranges of these indicators (2.4-5.9 dS/m, <25 meq/L and <39 meq/L, respectively; doi:10.1080/1065657x.2004.10702184). Nevertheless, it is a well-known fact high levels of salt in organic amendments can result in a reduction of soil productivity because of structural breakdown and/or plant-growth inhibition (doi:10.1016/bs.agron.2017.03.002). So, a monitoring soil salinity and sodium levels by periodic soil tests is often required. Therefore, there are often restrictions on the content of salts in manure. It is particularly important to follow these restrictions when using manure or compost on semiarid soils, as described in this manuscript. Therefore, data how much manure used in the study is typical should be provided in the manuscript.
The second critical remark relates to the rainfall simulating. The authors wrote the soils samples were exposed to an 80 mm simulated rainstorm with rain intensity of 55 mm/h. However, eighty millimeters are a half of the monthly precipitation rate or more in Israel even in the winter months. Intensity of 55 mm/h, in its turn, means violent rain (https://web.archive.org/web/20120114162401/http://www.metoffice.gov.uk/media/pdf/4/1/No._03_-_Water_in_the_Atmosphere.pdf). So, I strongly recommend to indicate that the conditions chosen by the authors were extreme and not typical. This fact should be indicated not only when describing the methods, but also when discussing the results and in the conclusion.
Particular remarks
Lines 72-73. Please check font formatting.
Line 116. Please give the names for the studied soils according WRB classification.
Line 123. Please correct CaCo3.
Line 125. Please refer to the paper where soil/water ratio 1/4.5 (w/w) is recommended to get a soil water extract.
Line 178. Please correct CACO3.
Line 187. May be authors want to delete “the two manures”.
Line 194. The standard deviation values should be accompanied by replications. Please indicate (n=…).
Table 1. The values of standard deviations must be specified with the same number of decimals as the average. Approximate values are not allowed (case with EC and sandy soil) Please correct.
Table 2. Please correct PH.
Table 2. Studied organic amendments were initially introduced as industrial composted manure (named “compost”) and raw manure (named “yard manure”). However, different names for these materials can be found in the text. Please uniform the names.
Author Response
We appreciate the reviewers and editor positive review.
Please see the attached file with our reply to the 2 reviewers.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear Author, Dear Editor,
General considerations
The manuscript deals about effects of livestock manures on soil structure stability and soil erosion under simulated rainfall.
The subject is of general interest and useful for understanding behaviours, applicability, and field management.
The study, from the introduction to the conclusions, is well described, sampling and experimental plan also are clear, soils and experimental procedures too. On our opinion, it’s a clear paper about ready for publication with some few minor adds suggestions as below.
Introduction, Material and Methods
Okay, nothing to add
Results and Discussion
In Figures 1-3 marks with colours could help reading.
Infiltration:
Okay, nothing to add
Runoff:
L.219 “Surface runoff, which is the inverse of infiltration” maybe this sentence simplifies too much the reality.
L.227 Has some real crusting been observed? We should pay attention using the term of “crusting” because we have silt% in Hamra soil= 0.
L.228 “deformation of soil structure” maybe is more correct to say ‘collapse’ or ‘degradation’ of structure
Soil loss:
Figs 1, 2 and 3: better to add in legend or captions of the figure the meaning of a, b, ab (which is statistical groups and or statistical difference, I suppose).
Yard manure and compost disparities:
Fig. 4: better to add labels for X plots in A and B, maybe the values 10, 30, 50, 70 are not necessary because (I see from L.284) the first block starts at 20mm in observation.
But in fig 4C a value of 50mm is called in L.310, so it’s not clear if is a continuous scale or scaled each 20mm.
Summary and Conclusions
All is fine.
Author Response
We appreciate the reviewers and editor positive review.
Please see the attached file with our reply to the 2 reviewers.
Author Response File: Author Response.pdf
