نوع مقاله : مقاله پژوهشی
نویسندگان
1 بخش علوم و مهندسی حاک، دانشکده کشاورزی، دانشگاه شیراز، شیراز، ایران
2 بخش علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه شیراز
3 بخش علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه شیراز، شیراز، ایران
4 بخش مهندسی بیوسیستم، دانشکده کشاورزی، دانشگاه شیراز، شیراز، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
One of the challenges of recent centuries is food security, which results from population growth. Land management changes can adversely affect soil properties, leading to irreparable damage in the future. Therefore, it is important to investigate the effects of land use changes to improve land management practices. This study aimed to investigate the effect of land use change on physical and chemical properties of 300 completely random samples collected from four land uses of forest, agriculture, poor pasture, and strong pasture in Fars province. The results showed that land use changes affected the studied properties. The highest organic matter (3.45%) and the mean weight diameter (2.2 mm) were obtained in the forest and agricultural land uses, respectively, with good plant cover, which can be due to more input and less output of organic matter in these land uses. Also, in these lands, the pH of the soils has decreased due to the exudation of organic acids from the roots of the plants, and the highest pH value (8.39) was observed in the poor pasture land use. Bulk density was not significantly different among the studied land uses. However, in the poor pastures due to the destruction of aggregate and excessive livestock grazing, the apparent density was 5% higher than that of the other three land uses. Overall, as land use shifted from forest to strong pasture, the soil quality decreased due to the loss of plant cover in poor pastures. Therefore, consistent soil monitoring is essential for making appropriate decisions about the future of soil management against land use change.
کلیدواژهها [English]
EXTENDED ABSTRACT
Land use change has an impact on the physical and chemical characteristics of the soil. This issue can affect soil destruction and erosion. Considering the planting of non-agricultural lands with population growth and the need for more access to food resources, it is necessary to investigate the effects of land use change on the physical and chemical characteristics of the soil. In other words, management systems can have direct effects on soil properties. Therefore, this research was conducted to investigate the impact of land use change on some physical and chemical properties of soil and to provide useful knowledge for land management in the future.
Soil samples were collected from 300 points in the northern half of Fars province and from a depth of 0 to 30 cm in four land uses: forest, agriculture, strong pasture, and poor pasture. A part of the soil of each sample was passed through a 2 mm sieve and the other part of each sample was passed through an 8 mm sieve to measure common physicochemical characteristics. The data were analyzed using SPSS version 27.0.1 software in a completely randomized design. Mean comparison was also done using Duncan's multiple range test to evaluate the difference in the mean values of soil characteristics among the studied land uses. The normality of the data was also checked using the Kolmogorov-Smirnov test.
Results showed that the percentage of sand, silt, and clay in different uses has significant differences. The mean value of sand in poor pasture land was less than the other land uses. The highest amount of silt was obtained in agricultural lands and the lowest amount was obtained in poor pasture lands. The highest and lowest amount of clay was obtained in agricultural lands and poor pastures, respectively. The highest and lowest mean weight diameters of soil particles were observed in agricultural lands and poor pastures, respectively, and they were significantly different from each other. The mean weight diameter of soil aggregates in forest land use was higher than that of strong pasture lands, although no significant difference was observed between these land uses. Different land uses did not have a significant effect on the bulk density of the soil, although the highest value of the bulk density was obtained in the poor pastures and the lowest value was obtained in the lands with good plant cover. The poor pasture soils showed the highest pH value, which had a significant difference with the three land uses of strong pasture, agriculture, and forest. While there was no statistically significant difference between soil pH values in the strong pasture, agriculture, and forest land uses. There is a significant difference between the electrical conductivity of the soil in the studied land uses. So that the highest amount of EC was observed in the soils of poor pastures and the lowest amount was observed in strong pastures. Also, agricultural lands had higher electrical conductivity compared to the forest. Land use has a significant effect on the amount of soil organic matter, so that the highest amount of organic matter was observed in forest lands and the lowest amount of organic matter was observed in poor pasture lands. However, no statistically significant difference was observed between organic matter in the pasture and agricultural land uses.
The results showed that land use affects the physical and chemical characteristics of the soils in such a way that the amount of organic matter and the mean weight diameter of aggregates are higher in lands with better plant cover, which is due to the effect of plants on the creation of stable soil aggregates. Forest lands have a high potential for carbon sequestration in the soil, which can increase the stabilization and retention of carbon in the soil and thus prevent the release of carbon in the form of carbon dioxide into the atmosphere and reduce greenhouse gases and global warming. In agricultural lands, due to the use of fertilizers, lack of irrigation, and lack of drainage, the electrical conductivity is higher than in the other land uses. Also, in lands with appropriate plants, the pH of the soils has decreased due to the exudation of organic acids from the roots of the plants, and the highest pH value (8.39) was observed in the poor pasture land use. In general, investigating the effect of the type and land use change on soil characteristics can create a vision of the future of soils and the type of management required, which will help make decisions for the best possible management of soils and their preservation and protection.
Conceptualization, A.A.M., M.Z. and M.A.N.; methodology, Z.Z. and A.A.M.; software, Z.Z..; validation, A.A.M., Z.Z., M.Z., and M.A.N.; formal analysis, Z.Z.; investigation, A.A.M., Z.Z., M.Z., and M.A.N.; resources, A.A.M.; data curation, Z.Z.; writing-original draft preparation, Z.Z.; writing-review and editing, A.A.M., Z.Z., M.Z., and M.A.N.; visualization, A.A.M., Z.Z., M.Z., and M.A.N.; supervision, A.A.M.; project administration, A.A.M.; funding acquisition, A.A.M.
All authors have read and agreed to the published version of the manuscript.
All data generated or analysed during this study are included in this published article.
The authors would like to thank Shiraz University for providing all the needed facilities.
The authors avoided data fabrication, falsification, plagiarism, and misconduct.
The author declares no conflict of interest.
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