Modeling Water and Nitrogen Balance of Different Cropping Systems in the North China Plain

Round 1

Reviewer 1 Report

Modelling water and nitrogen balance of different cropping systems in the North China Plain

The paper is very well formulated and is clearly written in terms of clarity, use of data to inform practices, and appropriate use of a crop model. It provides useful insights into the water and N balance in these cropping systems and would be very valuable.

Apart from the changes suggested below, my only suggestion is to review the manuscript thoroughly for improvement in English grammar and sentence structure. There are several minor discrepancies and pending a English review, the manuscript should read well.

Line 45: it “has” also

Line 45: generally “have high water consumption”

Line 48: An estimated more than…

Line 49: which “dominatingly depends on”

Line 52: rapidly, at the rate of approx..

Line 57: Agronomically, it is an excessive application rate

Line 60-68: Please split into shorter, more understandable sentences.

Line 68: crop models estimate time span

In para 59-78: Include a few lines about why was the research accomplished using a crop model. Why not an actual field study. It would be nice to let the readers know why crop model is a beneficial tool for such an analyses.

Line 87: which is one of the most affected…

Line 90: increased trend of dependence on chemical…

Section heading 2.2 should read as “Details of experimental design and management practices”

Line 125: Usually any soil moisture probes are subject to errors and uncertainties. Do you have any information that you collected or can cite another research that has looked into the accuracy of these particular sensor model, so we know that the data collection can be treated as such safely?

Section heading 2.4.3 should read as “Statistical Evaluation of the model”

Line 192: to measure

Line 196: should read as “Pearson correlation coefficient analysis was applied to quantify the magnitude of the collinearity between observed and predicted variables.”

Figure captions should not use any acronyms for variables, please mention full names. Please do this for all figures.

In figure 1: please assign some sublabels like (a), (b) to define what each graph denotes, for example, whether 2HIYopt or 2HIYfp, and depths.

It is crucial in present times to fairly distinguish various cropping systems for their water and N use, and the paper does a great job at accomplishing that in the North China Plain. You should say a few lines about why such analysis is useful and is necessary to conduct looking at future scenarios. It would be useful to include some details of similar studies that have accomplished the same objectives for their respective regions comparatively across various cropping systems. Here is a recent example very similar to your work:

M.S. Kukal, S. Irmak, 2020. Characterization of water use and productivity dynamics across four C3 and C4 row crops under optimal growth conditions. Agricultural Water Management. 227, 105840,

Author Response

Thank you very much for your constructive comments. The point to point guidance, greatly helped us to enhance manuscript. We have double read the entire content of the manuscript and carefully applied corrections. Please find attachment of word file. 

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript entitled ‘Modelling water and nitrogen balance of different cropping system in the North China Plain’ reports on how to optimize common cropping systems in NCP in terms of yield and N-leaching potentials. The authors used a modelling approach based on a water-heat-carbon-nitrogen-simulator introduced by Liang et al. (2016) (reference no 28) (https://www.nature.com/articles/srep25755). It was found that one harvest per year outperforms the other harvest regimes under environmental aspects (N-leaching), whereas a clear trade-off between yield and groundwater protection was shown. I was pleased reviewing this manuscript: The topic is of great contemporary relevance and it meets the scope of the journal, the methods are well described, the English language quality is high, the results are critically discussed, and the conclusions are covered by the results. However, I’ve provided 35 comments (please see attached annotated PDF) that should be addressed before publishing.

Comments for author File: Comments.pdf

Author Response

Thank you very much for your constructive comments. The point to point guidance, greatly helped us to enhance manuscript. We have double read the entire content of the manuscript and carefully applied corrections. Please find attachment of word file. 

Author Response File: Author Response.docx