Irrigated fields

The problem of OPP contamination of the bodies of water of Central Asia became relevant after OPPs started to be widely used together with OCPs in intensively treating irrigated fields. A large amount of the water used for irrigation returned to the rivers and canals. According to instructions, OPPs supposedly... 

Yaron B, Gerstl Z (1983) Herbicide residues in soils following point source application. Pesticide chemistry, human welfare and the environment. Pergamon Press, Oxford, pp 207-212 Yaron B, Bielorai H, Kliger L (1974) Fate of insecticides in an irrigated field—azinphosmethyl and tetradifon cases. J Environ Qual 3 413 17... 

For locating these ERWs, the most important characteristic of a body of water is its current. Currents may be nearly nonexistent in some stagnant ponds or irrigated fields. Currents in streams and rivers are usually consistent in direction but variable in velocity. Currents in tidal areas oscillate in direction and vary in velocity. Rapid currents have higher Reynolds numbers, hence more turbulence. Even rather modest velocities in water produce turbulence because the Reynolds number is higher with the higher density than in air. 

Recall that the term seafloor in this work designates the soil of the bottom of any body of water, whether sea, lake, pond, river, stream, or irrigated field. 

The test area was irrigated according to irrigation practices used in the Columbia Basin project area, where a 25 to 33% runoff flow from irrigated fields can be anticipated. Table I is a compilation of the results obtained from the flow measurements of the irrigation water applied and the runoff water. 

Lentz R. D., Sojka R. E., and Robins C. W. (1998) Reducing phosphorus losses from surface-irrigated fields emerging polyacrylamide technology. J. Envirort Qual. 27, 305-312. 

In high-selenium soils of some arid regions, selenate is a problem pollutant in the drainage water of irrigated fields, while selenite is not. Develop a plausible argument based on chemical principles to explain this observation. 

The peak atrazine concentrations in Nebraska were observed down-gradient from irrigated fields, at the end of the irrigation season (55) residue levels diminished with lateral distance (58). There was some areal and vertical association with nitrate concentration, but no correlation could be drawn with dissolved organic carbon (of which atrazine would constitute <<1%). 

Site Selection. Nine 160-acre (65-ha) irrigated fields in two of the main potato-growing counties of Wisconsin (Portage and Waushara, 6.4 and 2.2 million cwt. or 3.2 and 1.1 million quintals in 1981) were selected for study. Soils in each field were well drained sands or loamy sands, mainly of the Plainfield series... 

Clearly, the persistence and resultant distribution of aldicarb residues in groundwater are far from uniform, even under uniformly treated, uniformly irrigated fields. Residues seem to dissipate to levels of <10 yg/L or disappeared entirely by the time they reach depths of 3-4 m below the water table, but were more persistent in some areas than others. 

During the dry season, the formation of soil cracks, macro- and micropores is common in the Asian countries with monsoon climate. This process is especially important in irrigation fields where water fluxes will stimulate the pesticide migration downward in the soil profile. 

Isolation and identification of pathogenic microorganisms at wastewater-irrigated fields ratio in air and wastewater, Applied and Environmental Microbiology, 39, 1183-1190. 

Hydration and Irrigation. Field crops require vast amounts of water. When sources such as rainfall do... 

Treated water that meets water quahty standards may be used to irrigate fields or water livestock under certain circumstances. 

Agro-indnstry (since 1950), devoted to the cultivation of soya beans, rice, sugar cane and com maize and with irrigated fields for the production of vegetables. 

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