Irrigation water, use

The soil was collected from the Mezquital Valley, located near Pachuca in the State of Hidalgo (Mexico). The irrigation water used was slightly alkaline with a pH of 8.4. The experiment was carried out under greenhouse conditions. Soil collected from three sub sites was placed into cylindrical pots. Five treatments were established in order to study the effect of wastewater and urea on the cultivation of maize (Zen mays L.). The treatments were a) SMWW, maize plant plus wastewater b) SMUREA, maize plant plus urea as fertilizer c) SUREA, uncultivated soil and urea as fertilizer d) SWW, uncultivated soil plus wastewater and e) SCONTROL treatment, soil plus tap water. Soils from the SMWW and SWW treatments were irrigated with 1000 mL of wastewater every 7 days from the first day onwards, making a total of 13 times overall. This means that a total amount of mineral N equivalent to 120 kg N ha-1 was added to each maize plant, i.e. the recommended amount of N fertilizer for maize. 

Irrigation water used in crop production represents one of the most significant sources of contamination in fresh produce production. Contamination from manure heaps can readily be transferred to the water course via run off and subsequently disseminated over large distances via streams or rivers. When contaminated, water is used to irrigate crops, human pathogens can be directly transferred to plant tissue and persist through to harvest. 

Kramer, M. E., and Lim, D. V. (2004). A rapid and automated fiber optic-based biosensor assay for the detection of Salmonella in spent irrigation water used in the sprouting of sprout seeds. /. Food Prot. 67,46-52. 

Herbicides reduce irrigation costs. Weeds are also in direct competition with crop plants for water. Thus, irrigation water used by weeds is not available for the production of a crop. 

For addition of fertilizer to irrigation spray systems, complete water solubiHty, and hence use of the solution-type fertilizers, is essential. An additional requirement is that the fertilizer be of a composition that does not react with the normal mineral content ie, the hardness, of the irrigation water to form objectional scaling of equipment. 

Other burners are used for low capacity operations. A cascade or checker burner, ia which molten sulfur flows down through brick checkerwork countercurrent to a flow of air, is used ia small units with a sulfur trioxide converter to condition gases entering electrostatic precipitators at boiler plants operating on low sulfur coal. A small pan burner, which is fed with soHd, low carbon sulfur, is used to produce sulfur dioxide for solution ia irrigation water to control the pH and maintain porosity ia the soil. The same type of burner is used to disiafect wastewater ia this case sulfur dioxide is used iastead of chlorine. 

Carbon dioxide is sometimes added to irrigation water, in the same manner as fertilizer ammonia, in hard water regions. Carbon dioxide is also used with other gases in treating respiratory problems and in anesthesia. 

Irrigation has been practiced from the ancient time it is only in the twentieth century that the importance of the irrigation water quality was recognized [7]. The use of saline water may result in the reduction of crop yields. A high sodicity of water for irrigation may cause the deterioration in the physical properties of soils... 

To promote the use of poor quality water for irrigation, a field research study was conducted in three semi-arid regions with water scarceness in Syria in order to define, under field conditions, the wheat yield response function to irrigation water salinity, the effect of soil texture and structural characteristics on the irrigation water salinity threshold, and to compare this value with the conventional threshold value. 

A record of any irrigation schemes (type of system used and amount of water) used during the conduct of the trial must be recorded. Often, fertilizers and maintenance chemicals may be mixed into and delivered with the irrigation water, and, hence, details must be recorded. In the case of long-term studies such as soil dissipation or accumulation studies, additional information about the water being used for irrigation (pH, major ion constituents, etc.) must be recorded. 

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... 

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