I agree with the referees that the manuscript is interesting and timely, and also that English usage challenges mask its full potential. The revised manuscript is an improvement, but the manuscript would deliver its message more effectively if the wording was further clarified and simplified. The first sentence is an example. It states, "Nitrogen and water availability are two staple environmental elements in agroecosystems that can substantially alter canopy structure and physiology then crop growth, yielding large impacts on ecosystem regulating/production provisions."

How about instead, "Nitrogen and water availability alter canopy structure and physiology - and thereby crop growth and yield - in agroecosystems." This could be revised further, but says the same thing in 10 fewer words. Note that this is one of many examples throughout the manuscript where text could be made more efficient; most sentences should be revised. I personally found the Discussion to be interesting and insightful, noting the critical role of further text edits. Please continue revising the manuscript for clarity, after which I will not hesitate to recommend the manuscript be published in Biogeosciences. The following brief comments are meant to further improve the text.

On line 8, I think of a data assimilation (framework) as one in which a model and measurement are formally fused; the model isn't apparent in the subsequent statement or manuscript. Because I don't see any application of a formal data assimilation procedure (e.g. via the Kalman Filter or other Bayesian techniques), I recommend choosing another term. Simply linking remote sensing with leaf and plant-scale models isn't formal data assimilation, it's parameter fitting, which of course is fine.

On line 12, 'available nutrient availability'? A substantial amount of editing remains to be completed.

'amplified' on line 14 is qualitative. By how much? Quantitative abstracts are more effective.

please use the multiplication sign instead of the star on page 6 and elsewhere, noting page 7 as an excellent example of proper usage.

The use of 'low', 'normal', and 'high' in the results could be made more clear to the reader, perhaps by using a table.

51.60 micromoles of CO2 per m2 per second is perhaps too many significant digits. (See also '35.63% enhanced field mean of GPPday' below, and elsewhere.)

On page 9, which 'classical light response model'? In my opinion there are many.

Page 11 line 5 use of 'then'.

The revised manuscript represents and improvement, especially after it goes through additional English language editing by the Biogeosciences editorial staff for both usage and clarity. One example: "spatial heterogeneity in space" on page 16.

The authors curiously ignored my suggestion regarding significant digits throughout much of the text and tables, which does not arise from opinion, rather years of experience in measuring these and similar variables. Not only is it more accurate to list a representative amount of significant digits given measurement uncertainty, it is also easier for the reader to comprehend. The digital quality of some figures (e.g. Figure 2) is also lacking, at least in the built pdf, and Figure 4b could be improved for clarity. Please make these technical corrections and any additional steps that will enhance the readability of the manuscript, after which I will recommend it be accepted in Biogeosciences.

Sincerely,
Paul C. Stoy