increasing in concentration of heavy metals such as lead, cadmium, nickel, chromium and zinc cause considerable harmful effects on soil and environment. these elements are also hazardous to health of humans and wildlife. petrochemical plants and refineries pollution increase the amount of carcinogenic and tratogenic compounds in environment. the main goal of recent paper is the studying of soil...

The focus of soil erosion research in the Alps has been in two categories: (i) on-sitemeasurements, which are rather small scale point measurements on selected plots often constrained to irrigation experiments or (ii) off-site quantification of sediment delivery at the outlet of the catchment. Results of both categories pointed towards the importance of an intact vegetation cover to prevent soi...

An index to evaluate the phosphorus (P) pollution potential of agricultural fields was proposed by Lemunyon and Gilbert in 1993. Data .from three rainfall simulation studies were used to evaluate the relative importance of the variables in the P index. These studies included plots containing sorghum (Sorghum bicolor L.), winter wheat (Triticum aestivum L), and corn (Zea mays L) residues on whic...

A field study was conducted on hummocky terrain at the Manitoba Zero Tillage Association Research Farm near Brandon, Manitoba, Canada to determine the variability of crop yield as related to landscape position, soil properties, weed populations and plant disease. This information was used to develop a method for delineation of management units related to precision farming. Variable-rate fertili...

in this study, the process-based watershed model, soil and water assessment tool (swat), was used for simulating hydrology and sediment transport in the gharesou watershed and for identifying critical areas of soil erosion and water pollution. after model calibration and uncertainty analysis using sufi-2 (sequential uncertainty fitting, ver. 2) method, the outputs of the calibrated model were u...

Erosion potential was estimated for road approaches during 4 phases of a timber harvesting scheduled for 23 stream crossings in the Virginia Piedmont. The objectives of this study were to: (1) examine four different types of stream crossing structures (steel bridges, pole bridges, standard culverts, and reenforced fords) in order to determine if the type of stream crossing affects erosion poten...

Nitrogen balance in agroecosystems provides a quantitative framework of N inputs and outputs and retention in the soil that examines the sustainability of agricultural productivity and soil and environmental quality. Nitrogen inputs include N additions from manures and fertilizers, atmospheric depositions including wet and dry depositions, irrigation water, and biological N fixation. Nitrogen o...

Nitrogen fertilizer unabsorbed by crops eventually discharges into the environment through runoff, leaching and volatilization, resulting in three-dimensional (3D) pollution spanning from underground into space. Here we describe an approach for controlling nitrogen loss, developed using loss control fertilizer (LCF) prepared by adding modified natural nanoclay (attapulgite) to traditional ferti...