نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم خاک، دانشکده کشاورزی، دانشگاه زنجان، زنجان، ایران.
2 گروه علوم و مهندسی خاک، دانشکده مهندسی و فناوری کشاورزی، دانشگاه تهران، کرج، ایران
3 گروه علوم و مهندسی خاک، دانشکده مهندسی و فناوری کشاورزی دانشگاه تهران، کرج، ایران
4 گروه علوم و مهندسی خاک، دانشکده مهندسی و فناوری کشاورزی، دانشگاه تهران، کرج، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The wetting drying cycles, through the creation of SwellingShrinkage sequences in soil aggregates, lead to changes in the soil's microstructure. In this study, attempts were made to investigate changes in the geometric properties of loamy sand and silty clay soils by applying moisture cycles in different treatment conditions, including amendmentsand degradations. The hypothesis of this research is based on the premise that the presence of different treatment intensities of the effects of wetting drying cycles affects the soil's microstructure from the perspective of soil aggregates. Using ImageJ software, image processing was performed on 2D and 3D images acquired from soil blocks. In addition to soil aggregate volume and surface area, properties such as sphericity and flatness coefficients were estimated and used for the classification of soil aggregates. For statistical analysis and chart plotting, Orange 3 and Excel 2016 software were used. The results indicated that treatments such as calcium carbonate, cations, and organic matter increased the coefficient of soil aggregates elongation, while degradation treatments led to an increase in the coefficient of soil aggregates flatness in both studied soil textures. Geometric classification of soil aggregates revealed that a small portion of loamy sand soil aggregates were categorized as elongated soil aggregates, while more than half of them fell into the category of flatted soil aggregates. In silty clay soil samples, a uniform distribution of elongated, bladed, and flatted soil aggregates was observed. However, none of the studied treatments resulted in soil aggregates falling into the category of compacted soil. Considering the direct impact of soil aggregate shape on the hydraulic conductivity of soils, the method employed in this research can effectively determine the microstructural status of soils from the perspective of soil aggregates.
کلیدواژهها [English]
Using micromorphological techniques for geometrical classification of soil aggregates affected by various treatments
EXTENDED ABSTRACT
Soil microstructure plays a pivotal role in its overall health and functionality. Wettingdrying cycles, which induce SwellingShrinkage sequences in soil aggregates, are known to have a significant impact on soil microstructure. This study sought to explore the alterations in the geometric properties of two distinct soil types, namely loamy sand and silty clay, by subjecting them to varying moisture conditions, involving both enhancements and deteriorations. The central premise of this research revolves around the notion that different levels of treatment intensity during wettingdrying cycles exert discernible effects on soil microstructure at the soil aggregate level.
The primary objective of this research was to investigate how wettingdrying cycles, with differing treatment conditions, influence the microstructural attributes of loamy sand and silty clay soils. These treatment conditions encompassed the application of amendments like calcium carbonate, cations, and organic matter, as well as degradation processes. The aim was to discern how these treatments impact soil aggregate shape, volume, surface area, sphericity, and flatness coefficients, with the ultimate goal of classifying the soil aggregates based on their geometric attributes.
To achieve this objective, the study employed advanced techniques. Soil blocks were subjected to wettingdrying cycles, and 2D and 3D images of the soil aggregates were captured. Image processing was carried out using ImageJ software to extract valuable information. The parameters of interest included soil aggregate volume, surface area, sphericity, and flatness coefficients. These parameters served as the basis for the classification of soil aggregates. Statistical analysis and visualization were conducted using Orange 3 and Excel 2016 software to draw meaningful insights from the data.
The study's findings shed light on the significant impacts of the different treatments on soil microstructure. Treatments involving the addition of calcium carbonate, cations, and organic matter resulted in an increase in the coefficient of soil aggregate elongation. Conversely, degradation treatments led to an increase in the coefficient of soil aggregate flatness in both the loamy sand and silty clay soils. Further analysis revealed that in loamy sand soil samples, a small portion of the soil aggregates could be categorized as elongated, whereas more than half fell into the category of flattened soil aggregates. In silty clay soil samples, a more uniform distribution of elongated, bladed, and flattened soil aggregates was observed. However, none of the treatments led to soil aggregates being categorized as compacted soil.
This study underscores the critical significance of soil aggregate shape in shaping soil hydraulic conductivity and, by extension, its impact on agriculture, environmental science, and geotechnical engineering. The research methodology demonstrated its effectiveness in providing a comprehensive view of soil microstructure dynamics under the influence of wettingdrying cycles and diverse treatment conditions. These insights are invaluable, contributing to a more profound comprehension of how soils react to environmental changes. Such knowledge is vital for sustainable land management and agriculture practices, facilitating optimized irrigation, resource conservation, and enhanced crop yields. Beyond agriculture, it holds substantial ecological implications by enabling us to better mitigate the effects of climate change and soil degradation. Moreover, in geotechnical engineering, it offers a powerful tool to improve the safety and durability of civil engineering projects. Overall, this study's findings serve as a foundation for more informed and sustainable practices in a world where responsible land use and environmental stewardship are increasingly critical.