1گروه خاکشناسی، دانشکده کشاورزی، دانشگاه زنجان، زنجان، ایران.
2گروه خاکشناسی، دانشکده کشاورزی، دانشگاه زنجان، زنجان، ایران
3مؤسسه تحقیقات خاک و آب، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران
4مؤسسه تحقیقات خاک و آب، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
چکیده
تغییر کاربری اراضی یکی از مهمترین عوامل مؤثر بر کیفیت خاک و پایداری اکوسیستمهای خاکی محسوب میشود، بهویژه در مناطق نیمهخشک که منابع خاک با تهدیدهای جدی مواجه هستند. هدف این مطالعه، بررسی اثر تغییر کاربری اراضی بایر به باغ زیتون بر ویژگیهای فیزیکی، شیمیایی و زیستی خاک در منطقه لوشان، استان گیلان است. برای این منظور، سه منطقه همجوار با چشمانداز مشابه و شامل دو نوع کاربری بایر و باغ زیتون انتخاب و نمونهبرداری از ۷۲ نقطه در عمق ۰–۳۰ سانتیمتر انجام شد. سپس برخی از ویژگیهای مهم شیمیایی، فیزیکی و زیستی آن اندازهگیری شدند. نتایج نشان داد که محتوای کربن آلی و نیتروژن کل خاک در باغ زیتون بهترتیب 82/2 و 86/2 برابر بیشتر از زمین بایر بود. همچنین، مقدار فسفر و پتاسیم قابل جذب در باغ زیتون بهترتیب 42/18 درصد و 7/6 برابر بیشتر بود. ظرفیت تبادل کاتیونی در باغ زیتون 48/7 درصد افزایش یافت، در حالی که جرم مخصوص ظاهری خاک 19/5 درصد کاهش یافته است. درصد رس قابل انتشار نیز در باغ زیتون بهطور معناداری کاهش یافته و ۲۵/۱۸ درصد کمتر از زمین بایر است. از منظر زیستی، نرخ تنفس میکروبی در باغ زیتون 9/1 برابر بیشتر از زمین بایر ثبت شده است. این یافتهها نشان میدهند که تغییر کاربری زمینهای بایر به باغ زیتون منجر به بهبود قابل توجه ویژگیهای فیزیکی، شیمیایی و زیستی خاک در مناطق نیمهخشک میشود و میتواند با مطالعات تکمیلی، بهعنوان راهکاری مؤثر برای ارتقای بهرهوری اراضی در مناطق مشابه مورد استفاده قرار گیرد.
Assessing the Effects of Converting Barren Land to Olive Orchards on Soil Physical, Chemical, and Biological Properties: A Case Study in Guilan Province
نویسندگان [English]
سمیرا همتی1؛ Kamran Moravej2؛ Mir Naser Navidi3؛ Ahmad Golchin2؛ Javad Seyedmohammadi4
1Department of Soil Science, Faculty of Agriculture, University of Zanjan, Zanjan, Iran
2Department of Soil Science, Faculty of Agriculture, University of Zanjan, Zanjan, Iran
3Soil and Water Research Institute, Agricultural Research Education and Extension Organization (AREEO), Karaj, Iran
4Soil and Water Research Institute, Agricultural Research Education and Extension Organization (AREEO), Karaj, Iran
چکیده [English]
in Guilan Province
Introduction: Land use change has been widely recognized as a major anthropogenic driver altering soil quality and ecosystem function, particularly in semi-arid environments. The conversion of natural or unused lands to agricultural systems often induces significant transformations in the physical, chemical, and biological attributes of soil. In Iran, especially in the northern semi-arid zones, such changes have accelerated due to agricultural expansion, yet region-specific studies remain limited. The present study was designed to evaluate the impact of converting bare lands into olive orchards on key soil properties in Lushan, a representative semi-arid region in Guilan Province. Understanding how these changes affect soil functionality is essential for sustainable land management and ecological restoration.
Materials and Methods: The study area is located in the Lushan district of Guilan Province, encompassing approximately 300 hectares and characterized by semi-arid climatic conditions with an average annual precipitation of 273 mm. Two distinct land uses (bare land and olive orchard) were selected for soil sampling. Composite soil samples were collected from each land use type at a depth of 0–30 cm, with 12 replications per treatment. Physical properties such as texture, bulk density, and dispersible clay were measured using standard methods. Chemical properties including soil organic carbon, total nitrogen, available phosphorus, available potassium, calcium, magnesium, pH, electrical conductivity, and cation exchange capacity were analyzed. Biological indicators such as basal respiration and microbial quotient were also assessed. Data were statistically analyzed using ANOVA and Duncan’s multiple range test at p < 0.01 significance level.
Results and Discussion: The findings revealed that land use conversion significantly influenced most soil parameters. SOC increased by 2.82-fold in olive orchards compared to bare land. Total nitrogen rose by 2.86 times, respectively, while available phosphorus improved by 18.42% in olive orchards. Available potassium, particularly in olive orchards, reached 105.26 mg/kg 6.7 times higher than in bare soils. CEC increased by 7.48% in olive orchards, reflecting improved nutrient retention. EC levels rose by approximately 15% in agricultural soils, while pH declined from 8.42 in bare soils to 8.30 in olive orchards soils, indicating enhanced acid-neutral buffering and potential improvement in micronutrient availability. In terms of physical characteristics, bulk density was reduced by 5.19% in olive orchards, enhancing soil aeration and root growth potential. Dispersible clay content decreased by 25.18%, indicating greater soil structural stability and reduced erosion risk. Biologically, basal respiration increased significantly, with values of 0.540 mg CO₂ g⁻¹ in olive orchards, compared to 0.283 mg CO₂ g⁻¹ in bare soils. This reflects heightened microbial activity and improved organic matter turnover in cultivated soils. These results confirm that the adoption of agricultural land uses under managed conditions can lead to substantial improvements in soil health by enhancing organic matter content, nutrient cycling, microbial function, and structural stability.
Conclusion: The conversion of bare lands to olive orchards under semi-arid conditions of Guilan Province significantly enhanced soil physical, chemical, and biological properties. Improvements in SOC, nitrogen, phosphorus, potassium, and microbial activity suggest that such land use transformations, if well-managed, can contribute to restoring soil functionality and increasing sustainable productivity. However, monitoring potential issues such as salinity buildup and nutrient leaching remains essential. These findings underscore the importance of land use planning and adaptive soil management in semi-arid agroecosystems.
کلیدواژهها [English]
Land Use Change, Olive Orchard, Soil Quality, Soil Organic Carbon Stock, Soil Properties
آمار
تعداد مشاهده مقاله: 2
سامانه مدیریت نشریات علمی. طراحی و پیاده سازی از سیناوب