نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشکدگان کشاورزی و منابع طبیعی، دانشگاه تهران، کرج، ایران
2 گروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشکدگان کشاورزی و منابع طبیعی، دانشگاه تهران، کرج، ایران.
3 موسسه علوم زمین، بخش علوم خاک، دانشگاه لایبنیتس هانوفر، هانوفر، آلمان
4 گروه مدیریت دولتی، دانشکده مدیریت و اقتصاد، دانشگاه آزاد اسلامی واحد علوم و تحقیقات، تهران، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Drought and desertification are significant environmental and agricultural challenges in Iran and worldwide, which exacerbated by inefficient water consumption patterns. Given the considerable extent (43 million hectares) of low-yield desert lands in Iran, which generally have light-textured soils, it is essential to rehabilitate these lands and manage their water resources to enhance soil productivity. Therefore, the primary objective of this study is to determine the optimal amounts of bentonite and nano-bentonite as natural soil amendments and to evaluate their effectiveness in improving the physical and chemical properties of sandy soil. In this study, each level of bentonite, including rates of 10, 20, and 30 ton ha-1, was applied in combination with nano-bentonite levels of 0.25, 0.75, and 2.5 ton ha-1. These experimental treatments were mixed with the soil and incubated for three months at a temperature of 25°C and 80% field capacity. After the incubation period, soil properties, including saturation percentage (SP), bulk density (BD), texture, electrical conductivity of the saturated paste extract (ECe), Ph and cation exchange capacity (CEC), were measured. The experiment was conducted in a completely randomized design with 10 treatments in three replications for bentonite and nano-bentonite, and the experimental data were analyzed using Minitab 16 software. Results showed that the treatment with bentonite at 30 ton ha-1 and nano-bentonite at 2.5 ton ha-1 had significant positive effects on the measured physicochemical properties of the soil. Analysis of variance revealed that bentonite and nano-bentonite treatments had significant effects on soil CEC, ECe, BD, and SP. Clustering of the results further indicated that the treatments of 30 ton ha-1 of bentonite plus 0.75 ton ha-1 of nano-bentonite and 30 ton ha-1 of bentonite plus 2.5 ton ha-1 of nano-bentonite had the greatest impact on improving the physical and chemical properties studied. Considering the experimental data, statistical results, and clustering of the treatments, the application of 30 ton ha-1 of bentonite plus 2.5 ton ha-1 of nano-bentonite was selected as the most suitable treatment for amending sandy soils in arid and semi-arid regions. This treatment effectively contributed to improving the physical and chemical properties of sandy soil, including reducing BD, increasing SP, enhancing CEC and OC content, and lowering soil ECe.
کلیدواژه‌ها [English]
EXTENDED ABSTRACT
Drought and desertification are among the major environmental and agricultural challenges in Iran, exacerbated by inappropriate water consumption patterns and inadequate resource management. Over half of Iran's territory falls within arid and hyper-arid climates, which presents a significant challenge for the country and underscores the need for intelligent water resource management and land conservation, especially in areas with sandy and light soils’ texture. A substantial portion of Iran’s low-yield and desert lands (approximately 43 million hectares) consists of sandy soils with low productivity for crops production. Given the economic and environmental importance of utilizing these lands and the need to enhance their productive capacity, soil reclamation and management have become imperative. The primary aim of this study is to determine the optimal amounts of bentonite and nano-bentonite as soil amendments and assess their effectiveness in improving the physical and chemical properties of sandy soils. This study also seeks to develop a suitable formulation for the physical, chemical, and economic improvements of low-yield sandy soils and to identify the best treatment for soil enhancement.
This research utilized aeolian sandy soil samples collected from Najmabad village in Nazarabad County, Alborz Province. After collection, the soil samples were transferred to the laboratory, air-dried, and sieved through a 2-mm mesh. The soil treatments included bentonite at three levels (10, 20, and 30 tons per hectare) and nano-bentonite at three levels (0.25, 0.75, and 2.5 tons per hectare). Zanjan bentonite was used as the source material for extracting nano-bentonite. Nano-bentonite was prepared using the precipitation method, where particles were separated by manual stirring. The solution was then precipitated with magnesium chloride, and the nano-bentonite was dried and ground. Then, sandy soil was mixed with bentonite and nano-bentonite and the treated soil were incubated for 12 weeks at 25°C and 80% humidity. After this period, the physical and chemical properties of the soil, including bulk density, saturation moisture, pH, electrical conductivity (ECe) and cation exchange capacity (CEC) were determined. The study was conducted using a completely randomized design with 9 treatments and 3 replicates. The experimenta data were analyzed using Minitab 16 software, applying statistical methods including Analysis of Variance (ANOVA), Tukey's test, Principal Component Analysis (PCA), and clustering. ANOVA and Tukey's test were used to identify significant differences between treatments, while PCA was employed for dimensionality reduction and pattern recognition. Clustering was utilized to group treatments based on similar characteristics.
The analysis revealed that applying bentonite at 30 t ha-1 and nano-bentonite at 2.5 t ha-1 had significant and positive effects on soil properties. Specifically, this treatment resulted in increased cation exchange capacity (CEC) and saturation moisture, and reduced bulk density and electrical conductivity of saturation extract (ECe). ANOVA indicated significant differences between treatments concerning CEC, ECe, and bulk density. Additionally, clustering analysis showed that the combinations of 30 t ha-1 of bentonite + 0.75 t ha-1 of nano-bentonite and 30 t ha-1 of bentonite + 2.5 t ha-1 of nano-bentonite had the most substantial positive effects on the physical and chemical properties of the soil. These combinations notably improved cation exchange capacity, organic carbon content, soil moisture retention, and reduced bulk density.
The findings of this research demonstrate that the application of bentonite and nano-bentonite can effectively enhance the physical and chemical properties of sandy soils. In particular, the combination of 30 t ha-1 of bentonite and 2.5 t ha-1 of nano-bentonite was identified as the most effective treatment for improving low-productivity sandy soils. This treatment significantly increased cation exchange capacity, soil moisture retention, and decreased bulk density and electrical conductivity of saturation extract. The results emphasize that using bentonite and nano-bentonite as soil amendments can be a highly effective strategy for improving the quality of sandy soils in arid and semi-arid regions and enhancing agricultural productivity in such environments.
Conceptualization; Alireza Raheb and Ahmad Heidari; methodology, Alireza Raheb, Ahmad Heidari, Mostafa Abdollahpour, Khodabakhsh Goodarzvand Chegini and Hamidreza Mokhtari Esfidvajani; validation, Alireza Raheb and Ahmad Heidari ; formal analysis, Hadis Khosravian Chatroodi and Sara Talaee Khosrowshahi; investigation, Hadis Khosravian Chatroodi; writing-original draft preparation, Hadis Khosravian Chatroodi; writing-Alireza Raheb; visualization, Hadis Khosravian Chatroodi; supervision, Alireza Raheb and Ahmad Heidari; project administration, Alireza Raheb; funding acquisition, Alireza Raheb and Ahmad Heidari. All authors have read and agreed to the published version of the manuscript.” All authors contributed equally to the conceptualization of the article and writing of the original and subsequent drafts.
Data available on request from the authors.
The authors would like to thank Soil Science Department of University of Tehran for providing equipments and Facilities, and Dr. Aida Bakhshi Khorramdareh for her participants of the present study.
The authors avoided data fabrication, falsification, plagiarism, and misconduct.
The author declares no conflict of interest
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