Investigation on the feasibility of straw incorporation to improve soil fertility without obviously increasing global warming potential

Zhang, Mengxue; Liao, Rujia; Zhang, Wenzhao; Fang, Cheng; Guerrero-Cruz, Simon; Táncsics, András; Zhu, Baoli; Wei, Wenxue; Sheng, Rong

doi:10.5194/egusphere-2025-6534

Preprints

https://doi.org/10.5194/egusphere-2025-6534

Preprints

02 Feb 2026

| 02 Feb 2026

Status: this preprint is open for discussion and under review for SOIL (SOIL).

Investigation on the feasibility of straw incorporation to improve soil fertility without obviously increasing global warming potential

Mengxue Zhang, Rujia Liao, Wenzhao Zhang, Cheng Fang, Simon Guerrero-Cruz, András Táncsics, Baoli Zhu, Wenxue Wei, and Rong Sheng

Abstract. The utility of rice straw as an organic fertilizer has been widely recognized as a promising approach to enhancing soil fertility. However, straw return is currently in a dilemma, as it may also provoke greenhouse gas (GHG) emissions, leading to serious environmental consequences. It is urgent to reveal the feasibility of straw incorporation regarding soil fertility improvement without notable increases in GHG emissions. Here, a soil microcosm experiment was employed to investigate the relationships between soil fertility and GHG fluxes and the underlying mechanisms influenced by straw amendments. Paddy soils were collected from a long-term rice straw incorporation field experiment. The dynamics of GHG fluxes and concentrations in soils, and the variations in the abundances of soil microbial communities were systematically determined. The results indicated that continuous rice straw incorporation at half of the harvest (ST1) obviously improved soil fertility but did not induce significant elevation of global warming potential (GWP). The minimal increase in GWP was mainly attributed to the significant reduction in N₂O emission and the slight rise in CH₄ emission compared to straw removal. The main mechanisms for these consequences were that ST1 possessed the highest nosZII abundance and the lowest nirS/nosZII ratio; meanwhile, its CH₄ production ability fluctuated around the soil CH₄ holding capacity, and most of the produced CH₄ was consumed by methanotrophs. In conclusion, rice straw can be incorporated into paddy soils at a suitable application rate, which can effectively enhance soil fertility without inducing an additional warming effect.

Received: 30 Dec 2025 – Discussion started: 02 Feb 2026

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.

Download & links

Preprint (PDF, 3320 KB)

Supplement (323 KB)

Download & links

Mengxue Zhang, Rujia Liao, Wenzhao Zhang, Cheng Fang, Simon Guerrero-Cruz, András Táncsics, Baoli Zhu, Wenxue Wei, and Rong Sheng

Status: open (until 02 Apr 2026)

Post a comment Subscribe to comment alert

CC1:
'Comment on egusphere-2025-6534', Jun Shan, 05 Feb 2026 reply
In this study, the authors claimed that rice straw could be incorporated into paddy soils by optimizing the straw rate and explained why the optimal rate minimized global warming potential mainly from the functional microbial perspective. The topic is interesting and well within the scope of SOIL journal. The MS is generally well-organized and well-written, and the methodology is sound. However, I have several comments to improve the quality of the MS. I recommend major revision before acceptance.

General comments
The first concern is about the title. The title is overstated. Investigating feasibility can include several aspects such as agronomic measures, soil types, climate regions, and land use, while the authors only focus on the rice straw rate and one paddy soil. I recommend reconsidering the title.

The authors used paddy soils from a long-term field to investigate GHG emission and microbial abundances. I acknowledge that the incubation approach has distinct advantages especially in elucidating the mechanism. The authors should claim more about why they chose to further conduct the microcosm experiment by following the field setting instead of directly sampling from the field.

The authors should explain more about why they only focused on nirS and nosZII while excluding their paired genes nirK and nosZI. I suggest adding one or two sentences in the Method section to clarify this.

The authors revealed that the soil has a holding capacity for CH₄ while not mentioning this for N₂O. From the concentration data, it seems soil did not hold N₂O at least not as long as CH₄. Why? It would be interesting if authors could explain a bit about this since the soil holds CH₄ while not holding N₂O may have implications for GHG mitigation strategy.

Besides CH₄ and N₂O, CO₂ is also an important GHG as it contributed up to 45% to the GWP (Table 2). I recommend elaborating more on the mechanisms related to CO₂ in the Discussion part.

Please improve your English and check the grammar throughout the paper.

Specific comments
Line 55-56. “This study aimed to…, and the related mechanisms”. I suggest rephrasing this sentence.
Line 66. Please add the description about water management of the field experiment since water regime could have a legacy impact on GHG emissions. This information would be valuable for potential readers interested in relevant topics.
Line 77-83. You sampled the headspace gas in the chamber and then the soil gas in the silicone tube (see Line 96-100). For consistency, I suggest adjusting the order here: For gas flux sampling, … For soil gas sampling, …
Line 84-85. “and each pot contained 1.27 kg (dry weight) of soil to reach about 10 cm in depth”. I suggest revising this sentence.
Line 99. What does “at the same time” mean? Did you sample headspace gas and soil gas simultaneously?
Line 193-195. The sentence is too long. Please revise it.
Line 249. “similar” should be “similarly”.
Line 266. It is inappropriate to use “fail to” here. We don’t expect an increase.
Line 291. I suggest deleting “with less than 5 g·m^-2”. It is meaningless to point out the number here. The GHG cumulative emissions from microcosms are incomparable among studies.
Line 293. Change “such a low” to “a much lower”, as the CH₄ cumulative emission should be only compared to the three other treatments in THIS study.
Line 298-300. Grammatical errors. Please revise the whole sentence.
Line 312-314. For now, the outlook could be more comprehensive. Consider revising this if possible.

Reply
Citation: https://doi.org/10.5194/egusphere-2025-6534-CC1
CC2:
'Comment on egusphere-2025-6534', Jupei Shen, 06 Feb 2026 reply
Rice straw incorporation is an important measure in the current sustainable development of agriculture, but its impact on greenhouse gas emissions remains controversial. The manuscript aimed to investigate the feasibility of straw incorporation to improve soil fertility without elevating global warming potential based on a microcosm experiment. This experiment has important practical value for optimizing fertilization strategies. Generally, it is an interesting topic, and the experimental design is rigorous. However, I have some concerns that should be addressed before the consideration for publication.
In the abstract, add the treatment information. Key data is also necessary in this part.

I would recommend to further point out the shortcomings of existing studies in terms of "synergistic effects of straw incorporation on both soil fertility and greenhouse gas emission, and the underlying mechanisms" in the Introduction section, which may help highlight the importance of the research.

Provide a hypothesis for this study.

L69, “from each treatment”

L85-87, the description of treatments is not clear. The straw treatments use the same amount of straw as did in the field experiment in the corresponding soils?

L89, give more detail process for urea and straw application.

Some detailed descriptions (such as gas collection devices) can be appropriately streamlined or moved to supplementary materials. Provide a schematic diagram of the cultivation device along with actual photos can give readers a better understanding.

In the "DNA Extraction and qPCR" section, briefly explain the reasons for choosing these functional genes (such as nosZII type instead of nosZI type).

It is recommended to provide the abundance data of nirK and nosZI and also the correlation analysis between greenhouse gas fluxes and microbial gene abundance.

In table 1, it would be better add the information for soils, which is derived from field samples.

L226-227, “copies per g dry soil…”

Some statements in the discussion can be further simplified to avoid the repetition of the results, and recommend focusing more on the explanation of the mechanism and literature comparison.

If possible, supplement the discussion on the relationship between CO₂ emissions and soil carbon accumulation, such as: "Although the CO₂ emissions of ST1 treatment increased significantly, the soil organic carbon content also rose simultaneously, indicating that straw returning to the field promoted the turnover and stability of soil carbon."

More relevant studies can be cited to enhance the persuasiveness in explaining N₂O emissions.

In the discussion part, add some comments for the abundance of detected genes compared to literature.

It is also recommended to add the limitations of this research.

The manuscript would benefit from further linguistic refinement.

Reply
Citation: https://doi.org/10.5194/egusphere-2025-6534-CC2

Mengxue Zhang, Rujia Liao, Wenzhao Zhang, Cheng Fang, Simon Guerrero-Cruz, András Táncsics, Baoli Zhu, Wenxue Wei, and Rong Sheng

Supplement

https://doi.org/10.5194/egusphere-2025-6534-supplement

Mengxue Zhang, Rujia Liao, Wenzhao Zhang, Cheng Fang, Simon Guerrero-Cruz, András Táncsics, Baoli Zhu, Wenxue Wei, and Rong Sheng

Viewed

Total article views: 126 (including HTML, PDF, and XML)

HTML	PDF	XML	Total	Supplement	BibTeX	EndNote
88	22	16	126	16	7	17

HTML: 88
PDF: 22
XML: 16
Total: 126
Supplement: 16
BibTeX: 7
EndNote: 17

Views and downloads (calculated since 02 Feb 2026)

Month	HTML	PDF	XML	Total
Feb 2026	88	22	16	126

Cumulative views and downloads (calculated since 02 Feb 2026)

Month	HTML	PDF	XML	Total
Feb 2026	88	22	16	126

Viewed (geographical distribution)

Total article views: 121 (including HTML, PDF, and XML) Thereof 121 with geography defined and 0 with unknown origin.

Country	#	Views	%

Latest update: 26 Feb 2026

Short summary

To return straw or not to return? We demonstrate that rice straw incorporation at half of the harvest enhanced soil fertility without additional global warming potential (GWP). This minimal increase in GWP relied on the highest nosZII abundance and the lowest nirS/nosZII ratio, and the CH₄ production being just above the soil CH₄ holding capacity. We offer a viable strategy to scientifically manage rice straw for climate-smart sustainable rice agriculture.


Total:	0
HTML:	0
PDF:	0
XML:	0