We used the Soil and Water Assessment Tool (SWAT) to simulate point and non-point source pollution of nitrate in a mesoscale mountainous catchment. The results show that the model efficiency for daily discharge is 0.81 for the calibration period (November 1990 to December 1993) and 0.56 for the validation period (April 2000 to January 2003). The model efficiency for monthly nitrate load is 0.66...

Soil nutrient depletion is a major concern in terms of resource utilization and optimization of production in the middle hills of Nepal. Soil and nutrient losses from agricultural land is responsible for pollution of surface waters and this reduces the productive capacity of land. A field experiment was initiated in May 2001 on acidic sandy loam soil in Kavre district; Nepal to investigate the ...

Changes in sulphur and nitrogen pollution in Swedish forests have been assessed in relation to European emission reductions, based on measurements in the Swedish Throughfall Monitoring Network. Measurements were analysed over 20 years with a focus on the 12-year period 1996 to 2008. Air concentrations of SO(2) and NO(2), have decreased. The SO(4)-deposition has decreased in parallel with the Eu...

in this study we report the rock magnetic properties of surface soil samples and their spatialvariability from the northernmost district of kerala to understand pedogenic processes and soil erosion. themagnetic signal is mainly from fine grained pedogenic magnetite as other sources like anthropogenic andlithogenic magnetite, bacterial magnetite and greigite are absent. the surface soil samples ...

Investigations were conducted on both the annual patterns of earthworm casting activity and Ž . the annual variations in soil and phosphorus P transfers by water runoff, under a temperate maize crop, to determine whether there is any time synchronism over the year between these processes that could increase risk of soil erosion. Cast dynamics were measured at 15-day intervals for 1 year. Phosph...

Sustainable agricultural practices are needed to minimize nitrate leaching. The crop-soil simulation model STICS coupled with a geographic information system was used to estimate the amount of NO3 leaching and to assess the ability of alternative management practices to reduce NO3 leaching in a nitrate vulnerable zone (NVZ) in La Rioja, Spain. Model performance was examined by comparing the sim...

introduction soil is one of the most valuable national resources that can be wasted by erosion phenomenon. therefore, prevention of soil erosion is universally considered. erosion is a process by which soil particles are separated from their original context and can be moved to another location. rill erosion is a kind of water erosion in which detachment and movement of soil particles can be af...

this research was conducted in a part of the dry farming lands of the southern guilan province, aimed at examining the impact of tillage erosion on the soil displacement and consequently its productivity. in order to achieve the research aims, 18 sampling points were spotted in some different locations of the landscape in seven adjacent fields, based on the adjacency to the field ridges (border...