title: Spatial variation of salts in a Gyanpur canal command area.
abstract: Information about spatial pattern of salts is necessary for site specific management. Data generation storage and analysis are the most common problems. Finite difference models are the simulation tools which can be successfully adopted to study and analyze spatial variations of salts. A field study was conducted at four villages of Handia Block District Allahabad state of Uttar Pradesh India, near Gyanpur canal command area. Forty eight soil samples at 0-5, 10-15, 20-25, and 35-40 cm were drawn for the study of cropped area at 1, 5, 10, and 20 km from the main canal. Newton's Forward Difference Interpolation Model was applied to predict the salt contents at varying depths and spatial distances. The Model shows that pH and EC of soil has increasing trend at 0-20 cm depth and thereafter decreases with the increase in depth, the values ranged between 7.2-8.4 and 0.12-0.45 mmhos/cm, respectively. Similar spatially horizontal trend was also observed for pH, EC, and Cl. The chloride content decreases sharply after 0-20 cm depth and ranged between 38 and 163 ppm. Calcium content also showed similar trend in the same soil depth and thereafter decreasing trend 11.38 to 60 ppm. Similar spatially horizontal trends were also observed for pH, EC, and Cl contents. The magnesium content in the vicinity of canal and at the farthest site has shown depth wise decrease. The middle area have shown sharp increase in magnesium showed sharp depth wise decrease near the canal and at farthest observation from the canal. At the middle area, initially the sharp increase was predicted until 20 cm depth and thereafter sharp decrease. The value ranged between 3 and 16.8 ppm. Sodium content in the nearby areas of canal showed sharp depth wise decrease, but the farther areas have been recorded an increase after 0-20 cm depth. The value of Na ranged between 18.7 and 35.9 ppm. The simulated values are found to be in close consent of observed values having correlation range between 0.995607 and 1.0. Developed model provides simulated salt values at varying depths and in horizontal coordinates and can be successfully adopted for deciding management strategies for better crop production.
authors.affiliation: Department of Soil Water Land Engineering and Management, Allahabad Agricultural Institute, Allahabad, 211007, India. isaac_rk@hotmail.com
authors.forename: Rajendra Kumar
authors.initials: RK
authors.lastname: Isaac
authors.forename: Dinesh
authors.initials: D
authors.lastname: Kumar
authors.forename: Syed Mohd
authors.initials: SM
authors.lastname: Azmi
mesh_terms: D006863:Hydrogen-Ion Concentration; D007194:India; D008962:Models, Theoretical; D012492:Salts / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D012492:Salts; D012987:Soil; D014867:Water