Biochar Effects on Soil Properties and Wheat Biomass vary with Fertility Management
Round 1
Reviewer 1 Report
Overall this manuscript presents the results of a study examining the influence of biochar additions on wheat growth. The article is well written. There are few missing sub- and super-scripts as well as spacing issues highlighted in the attached pdf.
The only major issue - is the authors need to clarify what type of carbon analysis was performed -- LOI, combustion, acid digest, h2o2 oxidation ? The authors need to refine the results and discussion to this analytical result. The biochar addition is typical considered "elemental carbon" since it is not microbial active, which is a requirement by definition of the SOM/SOC pool.
The nutrient content of the biochar should be presented since you are mentioning it in the discussion.
the blank space on page 5 should be eliminated.
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Reviewer 2 Report
The manuscript presents data of interest and novelty. Beside this, the methodology and the use of English are correct.
Only several minor corrections should be made for publication.
Abstract: Lines 15-18, rewrite to improve the understanding.
Introduction:
It would be appropriate to give relevance to the role of N availability in the soil and how biochar can affect it.
According to the EBC, the biochar must have at least 50% C in order to be considered (line 26).
Please also consider the effect of feedstock on the pH and other properties of the biochar, not just the temperature (see for example Rosa et al., 2014; STOTEN).
Note that other authors have mentioned the loss of effectiveness of fertilizers when used with very high doses of biochar.
Materials and methods:
Please describe in more detail the production of biochar (reactor, residence time,...).
Describe in more detail how the biochar was applied to the soil. Do you have soil texture data?
Provide soil ash content data. Provide the methodology of analysis of the biochar pH (it is not possible 1:2 w in biochar).
Please measure (and provide the data) of the water holding capacity of soil and biochar. Have you taken into account the WHC of the biochar to adjust the field capacity. Why have you used the 100% field capacity? perhaps it is too much water.
Results:
Please explain in more detail the reasons in your opinion for the lack of survival of plants at high doses of biochar. Did you detect the presence of fungi?
In the conclusions please add a couple of lines of specific recommendations for farmers interested in the agronomic use of biochar
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
