Soil Chemical Properties Depending on Fertilization and Management in China: A Meta-Analysis
and Xiaoning Zhao 1,*
Round 1
Reviewer 1 Report
Flooded-flooded crop rotation and flooded crop are different. The difference is due to leaching of nutrients by water.
Why did the authors compare such different conditions for growing crops? Please, provide a justification.
Author Response
Point 1: Flooded-flooded crop rotation and flooded crop are different. The difference is due to leaching of nutrients by water. Why did the authors compare such different conditions for growing crops? Please, provide a justification.
Response 1: Soil fertility is a comprehensive reaction of physical, chemical and biological characteristics of soil, and it is the ability of soil to coordinate and supply crop growth from environmental conditions and nutrient conditions. The level of soil fertility is not only affected by soil types and parent materials, but also by the unique anaerobic/aerobic growth environment. In wheat-rice rotation, the topsoil is in a reduced state during rice planting and irrigation and in an oxidized state during wheat planting. This periodic alternating process of drying and wetting forms the unique chemical properties of soil. Furthermore, many paddy rice systems are very intensive with two or even three crops grown each year. To prevent losses through denitrification, N fertilizer is applied as ammonium or urea. Lack of oxygen prevents nitrification in most of the soil, resulting in prolonged periods of high ammonium concentrations after fertilizer applications under flooded conditions. Rice field soil thus provides a unique environment for soil microorganisms and their response to fertilizer input may differ between flooded systems and unflooded systems. Therefore, we choose the five different planting conditions (wheat-maize rotation, wheat, maize, wheat-rice rotation and rice) to compare the effects of fertilizers on soil chemical properties.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The work “Soil chemical properties depending on fertilization and management in China: A meta-analysis” (authors Shengnan Jia, Ding Yuan, Wenwen Li, Wei He, Sajjad Raza, Yakov Kuzyakov, Kazem Zamanian and Xiaoning Zhao) is devoted to evaluation of the influence of fertilizers on soil chemical properties. It is of interest to life scientists, as well as soil scientists and specialists in the field of agriculture and soil amelioration.
During the reading of the manuscript a number of comments arose:
Line 41. “Crop yields have increased since the application of mineral fertilizers in the 1950s (1950: wheat 0.6 t ha-1, maize: 1.0 t ha-1, rice: 2.1 t ha-1 and 2021: wheat 5.8 t ha-1, maize: 6.3 42 t ha-1, rice: 7.1 t ha-1)”. Possibly it is more correct to say: since the start of application of mineral fertilizers in the 1950s...
Lines 148, 164. “The variance (V) was calculated…” – compare with “…the equation wij = 1/ν; ν was variance”. Uppercase (V) or lowercase (v) letter?
Line 249. “The N had the lowest increase of AK (-25%) in rice… Maybe decrease?
Lines 268-269. “The increase of TN decreased under N (17% to 7%), NPK (31% to 12%)…”?. Please, check the language.
Lines 270-272. “The C/N increased faster (16-20 years) (-7% to 2.5%) under NPKM compared to mineral fertilizer (21-25 years) (-7% to 3%), NPKS (31-35 years) (-11% to 1.5%)…”. If authors are talking about the range of changes in the values of the chemical properties of interest for a certain period of time, then it is necessary to give the duration of this period of time, and not specify a narrow (four-year) interval of the timeline.
Lines 276-277. “… compared to other fertilizer during 35 cultivations (Figure 5k,l)”. 35 years?
Line 294. “The pH decreased in the sandy (0.2 to -1), silt (0.2 to -2) and clay loam (1.2 to -2.3) 294 soils with cultivation duration…”. May be pH changed?
Line 345. “…in china…”?
Line 406. Where is the Figure 7c?
Conclusion. The work after minor revision can be published in “Agronomy” journal
Reviewer: Dr. Anisimov Vyacheslav S., Ph.D., Head of Lab.
249032, Russian Institute of Radiology and Agroecology, Obninsk, Russia
Author Response
The work “Soil chemical properties depending on fertilization and management in China: A meta-analysis” (authors Shengnan Jia, Ding Yuan, Wenwen Li, Wei He, Sajjad Raza, Yakov Kuzyakov, Kazem Zamanian and Xiaoning Zhao) is devoted to evaluation of the influence of fertilizers on soil chemical properties. It is of interest to life scientists, as well as soil scientists and specialists in the field of agriculture and soil amelioration.
Response: Thank you so much for your affirmation of our research.
Point 1: Line 41. “Crop yields have increased since the application of mineral fertilizers in the 1950s (1950: wheat 0.6 t ha-1, maize: 1.0 t ha-1, rice: 2.1 t ha-1 and 2021: wheat 5.8 t ha-1, maize: 6.3 42 t ha-1, rice: 7.1 t ha-1)”. Possibly it is more correct to say: since the start of application of mineral fertilizers in the 1950s...
Response 1: Yes, your opinions are quite to the point. We have changed the sentence: Since the start of application of mineral fertilizers in the 1950s, the crop yields have increased (1950: wheat 0.6 t ha-1, maize: 1.0 t ha-1, rice: 2.1 t ha-1 and 2021: wheat 5.8 t ha-1, maize: 6.3 t ha-1, rice: 7.1 t ha-1).
Point 2: Lines 148, 164. “The variance (V) was calculated…” – compare with “…the equation wij = 1/ν; ν was variance”. Uppercase (V) or lowercase (v) letter?
Response 2: We unified the variance as "V" and modified the sentence as “the equation wij = 1/V; V was variance” in the manuscript.
Point 3: Line 249. “The N had the lowest increase of AK (-25%) in rice… Maybe decrease?
Response 3: Yes, you are right. We changed the sentence: The N decreased AK of 25% in rice and NPKM increased AK of 390% in wheat-maize (Figure 4u,x).
Point 4: Lines 268-269. “The increase of TN decreased under N (17% to 7%), NPK (31% to 12%)…”?. Please, check the language.
Response 4: We changed the sentence: The N, NPK, NPKS and NPKM decreased the increment of TN from 17% to 7%, 31% to 12%, 50% to 31%, and 70% to 50%. TN had the lowest increase during 26-30 years cultivation (Figure 5e,f).
Point 5: Lines 270-272. “The C/N increased faster (16-20 years) (-7% to 2.5%) under NPKM compared to mineral fertilizer (21-25 years) (-7% to 3%), NPKS (31-35 years) (-11% to 1.5%)…”. If authors are talking about the range of changes in the values of the chemical properties of interest for a certain period of time, then it is necessary to give the duration of this period of time, and not specify a narrow (four-year) interval of the timeline.
Response 5: We showed the year when C/N change increases fastest to positive values under the influence of fertilizers. We have modified the sentence: The C/N increased faster from -7% to 2.5% after 20 years then increased to 10% after 35 years under NPKM. And the mineral fertilizer increased C/N from -7% to 3% after 25 years, the NPKS increased C/N from -11% to 1.5% after 35 years (Figure 5g,h).
Point 6: Lines 276-277. “… compared to other fertilizer during 35 cultivations (Figure 5k,l)”. 35 years?
Response 6: Yes, you are right. We modified the sentence in the manuscript: The AN had the highest increase under NPKM (70% to 113%) compared to other fertilizer during 35 years cultivation (Figure 5k,l).
Point 7: Line 294. “The pH decreased in the sandy (0.2 to -1), silt (0.2 to -2) and clay loam (1.2 to -2.3) 294 soils with cultivation duration…”. May be pH changed?
Response 7: Yes, you are right. We modified the sentence: The pH change decreased in the sandy (0.2 to -1), silt (0.2 to -2) and clay loam (1.2 to -2.3) soils with cultivation duration and had the more alkaline pH values in clay loam soils (Figure 6a,b,c).
Point 8: Line 345. “…in china…”?
Response 8: We deleted this sentence and modified the next sentence as: Overuse of N fertilizers decreases nitrogen use efficiency, resulting in higher nitrate and acidity in soil solution because of nitrification process.
Point 9: Line 406. Where is the Figure 7c?
Response 9: We have modified the sentence: The NPK decreased C/N compared to NPKM greatly in maize by 0.85 times, wheat-rice by 0.69 times and rice by 0.88 times (Figure 7 b).
Author Response File: Author Response.pdf
