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Papers by Altaf Ali Siyal

Research paper thumbnail of Effect of water quality and methods of water application on the leaching efficiency of a saline soil

ABSTRACT Soil reclamation with traditional methods requires large quantities of fresh water. Ther... more ABSTRACT Soil reclamation with traditional methods requires large quantities of fresh water. Therefore, it becomes indispensable to reclaim saline soils with the minimum application of water. An experimental study was carried out to determine the effect of water quality and methods of water application on the leaching efficiency of a saline soil. Twenty seven leveled plots of size 2m x 2m were prepared in three blocks on a saline soil. Salts from these plots were leached with three different water qualities i.e. EC = 0.8 dS/m (T1), 1.2 dS/m (T2) and 2.0 dS/m (T3) , using three water application techniques viz. continuous leaching, intermittent leaching, horizontal leaching. The pre and post soil physical and chemical properties showed that the soil was clay loam in texture for 0-80 cm depth. The salt leaching results revealed that with intermittent leaching method (IL) 74.9% of salts from the soil depth 0-80 cm were leached down as compared to 68.84% and 65.76% of salts leached down with continuous leaching (CL) and horizontal leaching (HL) method respectively with application of 70 cm of water having EC = 0.8 dS/m. However, 63.70%, 72.72% and 64.79% of salts leached with CL, IL and HL methods respectively with application of 85 cm of water having EC = 1.2 dS/m and 60.45%, 68.38% and 59.03% of salts with CL, IL and HL methods respectively with application of 100 cm water having EC = 2.0 dS/m. The statistical analysis of the data showed highly significant (p < 0.01) decrease in EC of soil saturation extract of all plots after salt leaching with various water qualities. With application of 70 cm of water with EC = 0.8 dS/m to treatment T1 nearly 6 to 9% more salts were leached with IL method compared to other leaching methods. Similar trend was observed for other treatments. This suggests that under given soil and climatic conditions, IL method was efficient method of salt leaching followed by CL method even when marginal quality water was used.

Research paper thumbnail of Environmental Impact of Conversion of Natural Wetland into Reservoir: A Case Study of Chotiari Reservoir in Pakistan

World Environmental and Water Resources Congress 2019

Research paper thumbnail of Determination of Hydraulic Properties of Soil as a Porous Medium

Journal of Applied Sciences, 2002

Research paper thumbnail of Spatial Analysis of Soil Salinity in the Indus River Delta, Pakistan

Engineering, Technology & Applied Science Research, 2019

Soil salinization is one of the most damaging environmental problems in coastal areas, including ... more Soil salinization is one of the most damaging environmental problems in coastal areas, including Indus River Delta (IRD). Due to the reduction of flow in the Indus basin, saline water from the Arabian Sea is intruding into the IRD and has degraded the agricultural lands drastically. Focusing on the gravity of the problem, the present study was designed to explore the spatial distribution of soil salinity in the IRD. Physicochemical analysis of 375 soil samples randomly collected from 125 different locations within the study area was used. Analysis revealed that for the top 0-20cm of soil, about 66.4% of the samples had electrical conductivity (EC) values, and 72.8% sodium content (ESP) values higher than the FAO guidelines. Similarly, for soil depth of 20-40cm, 60.8% of the EC values, and 72% of ESP exceeded the safe limits. Finally, for 40-60cm of soil depth, 56.8% of the EC values and 79.2% of the ESP values were higher than the safe limits. Spatial analysis revealed that more tha...

Research paper thumbnail of Numerical Solution of the Salt Diffusion Equation for Non-Stirred Bathing Solutions

Journal of Applied Sciences, 2002

Research paper thumbnail of Movement of Effluent Discharge Towards Lateral Drain Under Different Impervious Layers and Water Table Depths

An experiment was conducted in a permeability tank constructed at the Laboratory of Department of... more An experiment was conducted in a permeability tank constructed at the Laboratory of Department of Land and Water Management. Two soils with different textures collected from Khesana Mori and Nasarpur were used in the experiment. Soils were analyzed for the textural class and hydraulic conductivity. The soil collected from Khesana mori was sandy with hydraulic conductivity of 6.9 m/day, while the soil brought from Nasarpur was clay loam with hydraulic conductivity of 0.0564 m/day. Three impervious layers were imposed at 100, 200, and 300mm depths and four water table depths were maintained from soil surface at 0.0, 30.0, 60.0, 90.0 mm depths above the lateral. The effluent discharge was measured by volumetric method and same was calculated using Hooghoudt’s formula. The results showed that the effluent discharge from laterals was maximum when the water table depth was maintained at soil surface under both sandy and clay loam soils. The effluent discharge decreased with the increase i...

Research paper thumbnail of Reclamation of Saline Clay Soil with Different Leaching Method

The availability of water for land reclamation is limited due to water shortage crises in the wor... more The availability of water for land reclamation is limited due to water shortage crises in the world. An experiment of leaching of saline soil in micro-plots of size 3m x 4 m was carried out with different leaching methods in order to assess their leaching efficiency. Three leaching methods viz. continuous ponding, continuous ponding With 5 cm salt crust removal (scrapping) and continuous ponding with tillage were used. Equal depth of water (70cm) was applied to all the plots replicated three times for 30 days. Soil samples were taken regularly from all plots at soil depths of 0, 20, 30, 40, 60 and 80 cm for determining the change in EC of the soil. The experimental results revealed that continuous ponding with tillage was efficient method of leaching than other leaching methods used in this experiment. The continuous ponding with tillage method of leaching was efficient because small aggregates were formed and the salts held in small aggregates diffused faster due to shorter diffusi...

Research paper thumbnail of Estimating Hydraulic Properties of Some Soil Series of Sindh

Quantitative description of soil hydraulic properties is necessary for determining the soil water... more Quantitative description of soil hydraulic properties is necessary for determining the soil water holding capacity, infiltration, percolation, and runoff rates and for modelling water and solute transport in the vadoze zone. Recognizing the key role of soil hydraulic properties in the management of irrigation scheduling, salinity and agricultural drainage, a study was conducted to determine hydraulic properties of the five soil series, commonly found in Sindh, through laboratory method and numerical modeling. Six free drainage experiments were carried out in the laboratory using Jhakkar, Matli, Miani, Sarhad and Sultanpur soil series to estimate their hydraulic properties. Oven dried soil samples of each soil series were filled in 15 plastic pipes of diameter 15 cm and length 30 cm with holes at the bottom for free drainage. Natural soil density and porosity was maintained in pipes by compaction. Tensiometers were installed in the center of each pipe and then pipes were filled with ...

Research paper thumbnail of Impact of 2010 super flood on rice crop of the Larkana Division, Pakistan

Research paper thumbnail of Application of GIS and Remote Sensing for Identification of Potential Runoff Harvesting Sites: A Case Study of Karoonjhar Mountainous Area, Pakistan

World Environmental and Water Resources Congress 2018, 2018

Research paper thumbnail of Biochars reduce irrigation water sodium adsorption ratio

Biochar, 2020

Irrigation water quality plays a vital role in sustaining crop productivity and feeding a growing... more Irrigation water quality plays a vital role in sustaining crop productivity and feeding a growing world population. In many countries, continued agricultural water reuse can lead to greater water-soluble salt concentrations, and in particular Na; finding means by which irrigation water Na, and thus sodium adsorption ratios (SAR), can be reduced would reduce the rate at which soil sodification occurs. Four biochars, containing a variety of organic functional groups and electrochemistries, were examined for their potential to sorb and remove Na from simulated irrigation water, and subsequently reduce water SAR. Two batch experiments examined the role that wheat straw biochar, lodgepole pine biochar, Kentucky bluegrass biochar, and hemp biochar played in terms of sorbing sodium over time or application rate. Of the four biochars examined, hemp biochar had the lowest oxidation–reduction potential (ORP; ~ 0–100 mV), sorbed the greatest Na amount (up to 923 mg kg−1), and released Ca and M...

Research paper thumbnail of Spatial and temporal dynamics of Pai forest vegetation in Pakistan assessed by RS and GIS

Journal of Forestry Research, 2016

Abstract Pai, an arid forest in Sindh Province of Pakistan, is important for the environmental, s... more Abstract Pai, an arid forest in Sindh Province of Pakistan, is important for the environmental, social, economic development and conservation of ecosystems of the province. Considering the significance of the forest for Sindh and the calls from the local population for its deforestation, we quantified the spatial and temporal variation in the vegetation of the forest and land surface temperature (LST) using optical and thermal Landsat satellite data. Our analysis of temporal (1987–2014) images with ArcGIS 10.1 revealed that the dense forest area was greatest at 725 ha (37 % of the total forest area) during 2013 while it was smallest at 217 ha (11 %) in 1992. The sparse forest area peaked during 1987 at 1115 ha (58 %) under shrubs whereas it was smallest at 840 ha (43 %) in 1992, and the maximum deforestation of Pai forest occurred during 1992. Spatial change in vegetation over a period of about 27 years (1987–2014) revealed that vegetation increased on an area of 735 ha (37 %), decreased on 427 ha (22 %), and there was no change on 808 ha (41 %) of the forest. Variation in temperature between shaded (dense forest) and unshaded areas (bare land) of the forest was from 6 to 10 °C. While the temperature difference between areas with sparse forest and bare land ranged from 4 to 6 °C. An inverse relationship between LST and NDVI of Pai forest with coefficients of determination of 0.944 and 0.917 was observed when NDVI was plotted against minimum and maximum LST, respectively. The vegetation in the forest increased with time and the areas of more dense Pai forest supported lower surface temperature and thus air temperature.

Research paper thumbnail of The effect of different fertigation strategies and furrow surface treatments on plant water and nitrogen use

Irrigation Science, 2015

scenarios with plastic and irrigation in alternate furrows showed a reduction in transpiration an... more scenarios with plastic and irrigation in alternate furrows showed a reduction in transpiration and yield, more water loss due to deep drainage, and less water lost due to evaporation. However, similar crop yields were obtained for this alternate furrow strategy as for the control furrow surface treatments. When only half the water was used for irrigation in this scenario, the reduction in yield was less than 20 % compared to the control treatments, producing higher water-use efficiency. Communicated by J. Hornbuckle.

Research paper thumbnail of Strategies to Reduce Nitrate Leaching under Furrow Irrigation

International Journal of Environmental Science and Development, 2013

Research paper thumbnail of Reclamation of Saline Soils by Partial Ponding: Simulations for Different Soils

Vadose Zone Journal, 2010

Research paper thumbnail of Modelling of Solute Transport from Single Soil Aggregate

Journal of Applied Sciences, 2002

Research paper thumbnail of Desalinization of Aggregated Saline Soil: Experiments on Columns of Spherical Aggregates

Journal of Applied Sciences, 2002

Research paper thumbnail of Water Depletion Effects on the Behavior of Salts in Saline Soil

Journal of Applied Sciences, 2002

Research paper thumbnail of Water Depletion Effects on Water Infiltration Rate, Salt Behavior, and Leaching Requirements in Saline Soil

Journal of Applied Sciences, 2002

Research paper thumbnail of Comparison of continuous and intermittent leaching methods for the reclamation of a saline soil

Research paper thumbnail of Effect of water quality and methods of water application on the leaching efficiency of a saline soil

ABSTRACT Soil reclamation with traditional methods requires large quantities of fresh water. Ther... more ABSTRACT Soil reclamation with traditional methods requires large quantities of fresh water. Therefore, it becomes indispensable to reclaim saline soils with the minimum application of water. An experimental study was carried out to determine the effect of water quality and methods of water application on the leaching efficiency of a saline soil. Twenty seven leveled plots of size 2m x 2m were prepared in three blocks on a saline soil. Salts from these plots were leached with three different water qualities i.e. EC = 0.8 dS/m (T1), 1.2 dS/m (T2) and 2.0 dS/m (T3) , using three water application techniques viz. continuous leaching, intermittent leaching, horizontal leaching. The pre and post soil physical and chemical properties showed that the soil was clay loam in texture for 0-80 cm depth. The salt leaching results revealed that with intermittent leaching method (IL) 74.9% of salts from the soil depth 0-80 cm were leached down as compared to 68.84% and 65.76% of salts leached down with continuous leaching (CL) and horizontal leaching (HL) method respectively with application of 70 cm of water having EC = 0.8 dS/m. However, 63.70%, 72.72% and 64.79% of salts leached with CL, IL and HL methods respectively with application of 85 cm of water having EC = 1.2 dS/m and 60.45%, 68.38% and 59.03% of salts with CL, IL and HL methods respectively with application of 100 cm water having EC = 2.0 dS/m. The statistical analysis of the data showed highly significant (p < 0.01) decrease in EC of soil saturation extract of all plots after salt leaching with various water qualities. With application of 70 cm of water with EC = 0.8 dS/m to treatment T1 nearly 6 to 9% more salts were leached with IL method compared to other leaching methods. Similar trend was observed for other treatments. This suggests that under given soil and climatic conditions, IL method was efficient method of salt leaching followed by CL method even when marginal quality water was used.

Research paper thumbnail of Environmental Impact of Conversion of Natural Wetland into Reservoir: A Case Study of Chotiari Reservoir in Pakistan

World Environmental and Water Resources Congress 2019

Research paper thumbnail of Determination of Hydraulic Properties of Soil as a Porous Medium

Journal of Applied Sciences, 2002

Research paper thumbnail of Spatial Analysis of Soil Salinity in the Indus River Delta, Pakistan

Engineering, Technology & Applied Science Research, 2019

Soil salinization is one of the most damaging environmental problems in coastal areas, including ... more Soil salinization is one of the most damaging environmental problems in coastal areas, including Indus River Delta (IRD). Due to the reduction of flow in the Indus basin, saline water from the Arabian Sea is intruding into the IRD and has degraded the agricultural lands drastically. Focusing on the gravity of the problem, the present study was designed to explore the spatial distribution of soil salinity in the IRD. Physicochemical analysis of 375 soil samples randomly collected from 125 different locations within the study area was used. Analysis revealed that for the top 0-20cm of soil, about 66.4% of the samples had electrical conductivity (EC) values, and 72.8% sodium content (ESP) values higher than the FAO guidelines. Similarly, for soil depth of 20-40cm, 60.8% of the EC values, and 72% of ESP exceeded the safe limits. Finally, for 40-60cm of soil depth, 56.8% of the EC values and 79.2% of the ESP values were higher than the safe limits. Spatial analysis revealed that more tha...

Research paper thumbnail of Numerical Solution of the Salt Diffusion Equation for Non-Stirred Bathing Solutions

Journal of Applied Sciences, 2002

Research paper thumbnail of Movement of Effluent Discharge Towards Lateral Drain Under Different Impervious Layers and Water Table Depths

An experiment was conducted in a permeability tank constructed at the Laboratory of Department of... more An experiment was conducted in a permeability tank constructed at the Laboratory of Department of Land and Water Management. Two soils with different textures collected from Khesana Mori and Nasarpur were used in the experiment. Soils were analyzed for the textural class and hydraulic conductivity. The soil collected from Khesana mori was sandy with hydraulic conductivity of 6.9 m/day, while the soil brought from Nasarpur was clay loam with hydraulic conductivity of 0.0564 m/day. Three impervious layers were imposed at 100, 200, and 300mm depths and four water table depths were maintained from soil surface at 0.0, 30.0, 60.0, 90.0 mm depths above the lateral. The effluent discharge was measured by volumetric method and same was calculated using Hooghoudt’s formula. The results showed that the effluent discharge from laterals was maximum when the water table depth was maintained at soil surface under both sandy and clay loam soils. The effluent discharge decreased with the increase i...

Research paper thumbnail of Reclamation of Saline Clay Soil with Different Leaching Method

The availability of water for land reclamation is limited due to water shortage crises in the wor... more The availability of water for land reclamation is limited due to water shortage crises in the world. An experiment of leaching of saline soil in micro-plots of size 3m x 4 m was carried out with different leaching methods in order to assess their leaching efficiency. Three leaching methods viz. continuous ponding, continuous ponding With 5 cm salt crust removal (scrapping) and continuous ponding with tillage were used. Equal depth of water (70cm) was applied to all the plots replicated three times for 30 days. Soil samples were taken regularly from all plots at soil depths of 0, 20, 30, 40, 60 and 80 cm for determining the change in EC of the soil. The experimental results revealed that continuous ponding with tillage was efficient method of leaching than other leaching methods used in this experiment. The continuous ponding with tillage method of leaching was efficient because small aggregates were formed and the salts held in small aggregates diffused faster due to shorter diffusi...

Research paper thumbnail of Estimating Hydraulic Properties of Some Soil Series of Sindh

Quantitative description of soil hydraulic properties is necessary for determining the soil water... more Quantitative description of soil hydraulic properties is necessary for determining the soil water holding capacity, infiltration, percolation, and runoff rates and for modelling water and solute transport in the vadoze zone. Recognizing the key role of soil hydraulic properties in the management of irrigation scheduling, salinity and agricultural drainage, a study was conducted to determine hydraulic properties of the five soil series, commonly found in Sindh, through laboratory method and numerical modeling. Six free drainage experiments were carried out in the laboratory using Jhakkar, Matli, Miani, Sarhad and Sultanpur soil series to estimate their hydraulic properties. Oven dried soil samples of each soil series were filled in 15 plastic pipes of diameter 15 cm and length 30 cm with holes at the bottom for free drainage. Natural soil density and porosity was maintained in pipes by compaction. Tensiometers were installed in the center of each pipe and then pipes were filled with ...

Research paper thumbnail of Impact of 2010 super flood on rice crop of the Larkana Division, Pakistan

Research paper thumbnail of Application of GIS and Remote Sensing for Identification of Potential Runoff Harvesting Sites: A Case Study of Karoonjhar Mountainous Area, Pakistan

World Environmental and Water Resources Congress 2018, 2018

Research paper thumbnail of Biochars reduce irrigation water sodium adsorption ratio

Biochar, 2020

Irrigation water quality plays a vital role in sustaining crop productivity and feeding a growing... more Irrigation water quality plays a vital role in sustaining crop productivity and feeding a growing world population. In many countries, continued agricultural water reuse can lead to greater water-soluble salt concentrations, and in particular Na; finding means by which irrigation water Na, and thus sodium adsorption ratios (SAR), can be reduced would reduce the rate at which soil sodification occurs. Four biochars, containing a variety of organic functional groups and electrochemistries, were examined for their potential to sorb and remove Na from simulated irrigation water, and subsequently reduce water SAR. Two batch experiments examined the role that wheat straw biochar, lodgepole pine biochar, Kentucky bluegrass biochar, and hemp biochar played in terms of sorbing sodium over time or application rate. Of the four biochars examined, hemp biochar had the lowest oxidation–reduction potential (ORP; ~ 0–100 mV), sorbed the greatest Na amount (up to 923 mg kg−1), and released Ca and M...

Research paper thumbnail of Spatial and temporal dynamics of Pai forest vegetation in Pakistan assessed by RS and GIS

Journal of Forestry Research, 2016

Abstract Pai, an arid forest in Sindh Province of Pakistan, is important for the environmental, s... more Abstract Pai, an arid forest in Sindh Province of Pakistan, is important for the environmental, social, economic development and conservation of ecosystems of the province. Considering the significance of the forest for Sindh and the calls from the local population for its deforestation, we quantified the spatial and temporal variation in the vegetation of the forest and land surface temperature (LST) using optical and thermal Landsat satellite data. Our analysis of temporal (1987–2014) images with ArcGIS 10.1 revealed that the dense forest area was greatest at 725 ha (37 % of the total forest area) during 2013 while it was smallest at 217 ha (11 %) in 1992. The sparse forest area peaked during 1987 at 1115 ha (58 %) under shrubs whereas it was smallest at 840 ha (43 %) in 1992, and the maximum deforestation of Pai forest occurred during 1992. Spatial change in vegetation over a period of about 27 years (1987–2014) revealed that vegetation increased on an area of 735 ha (37 %), decreased on 427 ha (22 %), and there was no change on 808 ha (41 %) of the forest. Variation in temperature between shaded (dense forest) and unshaded areas (bare land) of the forest was from 6 to 10 °C. While the temperature difference between areas with sparse forest and bare land ranged from 4 to 6 °C. An inverse relationship between LST and NDVI of Pai forest with coefficients of determination of 0.944 and 0.917 was observed when NDVI was plotted against minimum and maximum LST, respectively. The vegetation in the forest increased with time and the areas of more dense Pai forest supported lower surface temperature and thus air temperature.

Research paper thumbnail of The effect of different fertigation strategies and furrow surface treatments on plant water and nitrogen use

Irrigation Science, 2015

scenarios with plastic and irrigation in alternate furrows showed a reduction in transpiration an... more scenarios with plastic and irrigation in alternate furrows showed a reduction in transpiration and yield, more water loss due to deep drainage, and less water lost due to evaporation. However, similar crop yields were obtained for this alternate furrow strategy as for the control furrow surface treatments. When only half the water was used for irrigation in this scenario, the reduction in yield was less than 20 % compared to the control treatments, producing higher water-use efficiency. Communicated by J. Hornbuckle.

Research paper thumbnail of Strategies to Reduce Nitrate Leaching under Furrow Irrigation

International Journal of Environmental Science and Development, 2013

Research paper thumbnail of Reclamation of Saline Soils by Partial Ponding: Simulations for Different Soils

Vadose Zone Journal, 2010

Research paper thumbnail of Modelling of Solute Transport from Single Soil Aggregate

Journal of Applied Sciences, 2002

Research paper thumbnail of Desalinization of Aggregated Saline Soil: Experiments on Columns of Spherical Aggregates

Journal of Applied Sciences, 2002

Research paper thumbnail of Water Depletion Effects on the Behavior of Salts in Saline Soil

Journal of Applied Sciences, 2002

Research paper thumbnail of Water Depletion Effects on Water Infiltration Rate, Salt Behavior, and Leaching Requirements in Saline Soil

Journal of Applied Sciences, 2002

Research paper thumbnail of Comparison of continuous and intermittent leaching methods for the reclamation of a saline soil