تغییرات کربن آلی خاک در عمق وکاربری‌های مختلف و تأثیر آن بر برخی ویژگی‌های فیزیکی و شیمیایی خاک

نوع مقاله : مقاله پژوهشی

نویسندگان

• عاطفه توکلی ¹
• احمد گلچین ²
• پرویز کرمی ³
• شهریار صبح زاهدی ⁴

¹ گروه علوم و مهندسی خاک-دانشکده کشاورزی- دانشگاه زنجان- زنجان- ایران.

² گروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه زنجان، زنجان، ایران

³ گروه مرتع و آبخیزداری، دانشکده منابع طبیعی، دانشگاه کردستان، سنندج، ایران.

⁴ بخش تحقیقات جنگل، مرتع و آبخیزداری، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان گیلان، سازمان تحقیقات، آموزش و ترویج کشاورزی،

چکیده

کلیدواژه‌ها

• باغ چای
• تغییر کاربری
• جنگل
• شالیزار
• کربن آلی

موضوعات

• شیمی خاک

عنوان مقاله [English]

Variations in Soil Organic Carbon Across Different Depths and Land Uses and Their Impact on Selected Physical and Chemical Soil Properties

نویسندگان [English]

• Atefeh Tavakoli ¹
• Ahmad Golchin ²
• Parviz Karami ³
• Shahriar Sobh Zahedi ⁴

کلیدواژه‌ها [English]

• Forest
• Land use change
• Organic Carbon
• Paddy field
• Tea garden

Introduction 

Soil organic carbon (SOC) plays a vital role in global climate change, as even minor fluctuations can significantly impact atmospheric carbon dioxide levels and climate patterns. Additionally, SOC serves as a key indicator of soil health and fertility. One of the primary factors influencing SOC levels is land-use change, which has a substantial effect on SOC content. This study aims to compare the effects of different land uses on SOC levels and selected physical and chemical soil properties. Furthermore, it seeks to determine whether converting forest land to agricultural land inevitably leads to soil quality degradation.

 Materials and Methods 

This study investigates the impact of three distinct land uses—natural forest, tea plantation, and paddy field—on SOC and selected physical and chemical soil properties across five depth intervals: 0–20, 20–40, 40–60, 60–80, and 80–100 cm. The research was conducted at the Poplar and Fast-Growing Trees Research Station in western Gilan Province (Pish Hisar, Fuman). The selected land uses were located within the same area and in close proximity. A total of 45 composite soil samples were collected and transferred to the laboratory for analysis. The data were analyzed using a factorial experiment within a randomized complete block design (RCBD) with SAS 9.4 software. Two-way analysis of variance (ANOVA) was employed to assess the significance of the measured soil physical and chemical properties concerning land use and soil depth. Duncan's multiple range test (at 1% and 5% significance levels) was used for mean comparison, while Excel software was utilized for graph generation.

 Results and Discussion 

The findings revealed that the effects of land-use change, soil depth, and their interaction on the measured soil properties were statistically significant at the 1% probability level (P ≤ 0.01). The highest levels of SOC (34.73 g/kg), total nitrogen (3.42 g/kg), available phosphorus (60.27 mg/kg), available potassium (418.50 mg/kg), mean weight diameter of soil aggregates (2.14 mm), cation exchange capacity (29.77 cmol/kg), and plant-available water (15.15%) were observed in the 0–20 cm depth under tea plantation land use. In contrast, the highest bulk density (2.34 g/cm³) was recorded in the 80–100 cm depth under paddy field land use. 

Conclusion 

The results indicate that tea plantation land use effectively enhanced and improved soil physical and chemical properties. Conversely, converting natural forest to paddy fields resulted in soil quality degradation. These findings suggest that land-use changes, when accompanied by appropriate management practices, can not only achieve economic objectives but also help preserve and enhance soil quality.

Author Contributions

Conceptualization, A.T and A.G. methodology, A.T. and A.G.; software, A.T. and P.K.; validation, A.T., A.G. and P.K.; formal analysis, A.T and A.G.; investigation, A.T.; resources, A.T, A.G. and SH.S.Z.; data curation, A.T. and A.G; writing—original draft preparation, A.T.; writing—review and editing, A.T. and A.G.; visualization, A.T and P.K.; supervision,A.G.; project administration, A.G. and SH.S.Z.; funding acquisition, A.T. and A.G. All authors have read and agreed to the published version of the manuscript.

Data Availability Statement

Data available on request from the authors.

Acknowledgements

We would like to thank the University of Zanjan for providing the necessary facilities to conduct this research.

Ethical Considerations

The authors avoided data fabrication, falsification, plagiarism, and misconduct.

Conflict of interest

The author declares no conflict of interest.