Search published articles


Showing 64 results for Salinity
Application of Supervised Classification Algorithms in Long-Term Survey of Surface Soil Salinity by Using Remote Sensing: A Case Study of Atabiyeh Plain, Khuzestan Province
F. Golabkesh, A. Nazarpour, N. Ghanavati, T. Babaeinejad,
Volume 26, Issue 2 (9-2022)
Abstract

The current study aims to find the best methods of using remote sensing and supervised classification algorithms in long-term salinity monitoring of salinity changes in the Atabieh area with an area of 5000 hectares in the west of Khuzestan province. The procedure is based on the separation of different levels of saline soils utilizing information obtained from Landsat 7 and 8 satellite images (2001 to 2015) along with salinity data taken from the study area, and salinity indices including SI1, SI2, SI3, NDSI, IPVI, and VSSI. The results show the expansion of the saline zone trend in the soils of the study area, among which, soils with EC of more than 16 dS m-1 (very saline) have the highest frequency. The area of saline soils has increased significantly over the past 15 years, with a saline land area increasing by more than 90%. The percentage of salinity class is low (S1). According to this study, the only significant index in soil salinity at a 95% confidence level is the SI3 index, which has been able to have a good estimate of the increasing changes in soils in the region. The results of the supervised classification showed that the support vector machine (with an overall accuracy of 95.78 and a kappa coefficient of 0.89) is more accurate. After the vector machine method, the methods of minimum distance, maximum likelihood, and distance of Mahalanobis have the highest accuracy, respectively. Based on salinity maps obtained in years in 2001, 2005, 2010, and 2015, it can be said that the salinity rate in the whole of the study area was progressing and at the same time the salinity area in the middle and high classes increased decreased and on the other hand, the salinity area in the high class in 2001 gradually increased and distributed in 2015 throughout the region.


Optimal Tape Spacing and Water Use Efficiency for Wheat Crop on Silty Clay Loam Soil Texture
M. Farzamnia, M. Miran Zadeh,
Volume 26, Issue 4 (3-2023)
Abstract
The present study was carried out in the Mahyar region of Esfahan Province to determine optimum drip tape spacing for the wheat crops on a silty clay loam soil respecting grain yield as well as yield components, water use efficiency, and variations in the salinity within the soil profile. The experiment was performed for three years from 2017 to 2019 with a randomized complete block design with three replicates and four treatments. The treatments consisted of three tape spacings (A) at 45, (B) at 60, (C) at 75 cm, and the Control (D) was irrigated with the basin method. The same volume of irrigated water was applied to the drip treatments, A, B, and C in every irrigation interval, whereas for treatment D, the local farmers’ practice was followed. Based on the results from compound variance analysis, the treatment effect on both grain yield and biological yield, and on water use efficiency and harvest index was significant at 1% and 5% level of confidence, respectively. The mean water use efficiency in treatments A, B, C, and D was measured as 0.79, 0.79, 0.73, and 0.78 kg m-3; thus, treatments A, B, and D outperformed treatment C. A comparison between the salinity of the soil profile at the beginning and the end of the growing season revealed that the basin irrigation method was more effective on salt leaching than the drip tape system. The results of this study indicated that concerning water use efficiency and crop yield, drip tapes spaced at 45 or 60 cm outperformed those which were 75 cm apart. On the other hand, the work required for irrigation system installation as well as the amount of drip tape residues left on the field at the end of the growing season is larger for tapes spaced at 45 cm compared to those which are 60 cm apart. This will have a significant impact on farmers’ budgets and environmental issues. Therefore, it is recommended to lay the tapes 60 cm apart for the irrigation of wheat crops on silty clay loam soils.

Interaction of Salinity and Sugarcane Biochar on Cadmium Species in Two Contaminated Clayey and Sandy Soils with Cadmium
E. Mirzakhani, H.r. Motaghian, A.r. Hosseinpur,
Volume 27, Issue 3 (12-2023)
Abstract
In addition to the distribution of elements in the soil solid phase, element species in the solution are also very important due to their importance of providing elements for root uptake. For a deeper study of the chemical cycle of elements in saline soils treated with biochar, the study of speciation is very useful and provides a method to reduce or transform the toxicity caused by toxic elements in saline soils. Therefore, to investigate the effect of biochar on Cd speciation in two saline calcareous soils, 15 mg kg-1 Cd as cadmium chloride was added to the soil sample (200 g), and the soils were incubated for three weeks at 25±2 °C at 80% field capacity. After the incubation period, salinity levels of 20 and 40 mmol kg-1 as sodium chloride (equal to 3.65 and 7.30 dS m-1) were added to the soils. Then, the 1% (w/w) of the sugarcane bagasse and biochars produced at 400 and 600 °C were added to the soils, and then incubated for three months at 25±2 °C at 80% field capacity. At the end of the incubation period, for the speciation of Cd in the soil solution (in a 1 to 2 ratio), the concentration of dissolved cations and anions in the soil samples was measured. The results showed that the interaction between salinity, biochar, and soil on Cd2+, CdCl+, CdCl20, and Cd(SO4)22- was significant. The application of biochar in sandy soil reduced (p <0.05) the concentration of CdCl+, CdCl20, CdSO40, and CdOH+ species compared to the control soil, while it did not affect clay soil. Also, salinity caused by sodium chloride in sandy soil increased the concentration of CdCl+ and CdCl20 species and decreased CdSO40 and CdOH+ species compared to the control soil (p <0.05). The results showed that biochar in saline sandy soil was more effective than clay soil in reducing Cd toxicity.

Effects of Irrigation with Treated Sewage Effluent on the Chemical Characterstics of Soil under the Cultivation of Ground Cover Plants (Case Study: Parand City)
M. Kashi, S. Alizadeh Ajirlo, N. Najafi,
Volume 28, Issue 1 (5-2024)
Abstract
The reduction of water resources due to the issue of global climate change and population growth is one of the most critical issues facing the designers and planners of the development of green spaces in cities. Against these challenges, there is an urgent need to improve the efficiency of water consumption and chain use of water resources with suitable options. Due to the significant volume of urban wastewater Effluent, its reuse in green space irrigation is important from the point of view of water resource management from an ecological and economic point of view. The effect of the Parand city wastewater treatment plant on the chemical properties of soil under the cultivation of three types of cover crops (Frankinia (FR), Festuca (FE), Dichondra (DI)) in a bed with sandy loam soil is investigated. This study was conducted as a factorial experiment based on a completely randomized design using mixing of water and Effluent at 4 levels with irrigation treatments of zero (control), 50, 75, and 100% compared to fresh water and 3 replications, and then the soil chemistry characteristics such as pH, EC, OC, Na, Cl, Ca, and Mg were evaluated. The results obtained from the soil chemical analysis parameters showed that the pH value decreased in all the treatments with effluent compared to the control, and this decrease was not significant in any treatment. The values of EC and Cl have increased in all plants, and these values were significant in the FR100 treatments with an increase of about 195 and 561% compared to the control, and in the FE100 treatment with an increase of about 54 and 162%, respectively, at the 5% probability level. The amount of OC in the FR100 treatment was significant with an increase of about 41% compared to the control treatment, but in other plants, this ratio was not significant in any treatment. The maximum amount of Mg in the FR50 treatment was 30.27, which has a significant effect compared to other treatments. The amount of Na and Ca in the FR100 treatment was significant with an increase of about 343% and 130%, respectively, compared to the control treatment, while in FE and DI plants, this ratio was not significant in any treatment.

Page 4 from 4     

© 2024 CC BY-NC 4.0 | JWSS - Isfahan University of Technology

Designed & Developed by : Yektaweb