Irrigation Water Quality

Identification and management of the groundwater quality are of utmost importance for maintaining freshwater resources in arid and semi-arid areas, which is essential for sustainable development. Based on the quality of the groundwater in various areas, local policymakers and water resource managers can allocate the usage of resources for either drinking or agricultural purposes. This research aims to identify suitable areas of water pumping for drinking and agricultural harvest in the Tabriz aquifer, located in East Azerbaijan province, northwest Iran. A groundwater compatibility study was conducted by analyzing Electrical conductivity (EC), total dissolved solids (TDS), Chloride (Cl), Calcium (Ca), Magnesium (Mg), Sodium (Na), Potassium (K), Sulfate (SO4), Total hardness (TH), Bicarbonate (HCO3), pH, carbonate (CO3), the and Sodium Adsorption Ratio (SAR) obtained from 39 wells in the time period from 2003 to 2014. The Water Quality Index (WQI) and irrigation water quality (IWQ) index are respectively utilized due to their high importance in identifying the quality of water resources for irrigation and drinking purposes. The WQI index zoning for drinking classified water as excellent, good, or poor. The study concludes that most drinking water harvested for urban and rural areas is 'excellent water' or 'good water'. The IWQ index average for the study area is reported to be in the range of 25.9 to 34.55. The results further revealed that about 37 percent (296 km 2) of groundwater has high compatibility, and 63 percent of the study area (495 km 2) has average compatibility for agricultural purposes. The trend of IWQ and WQI indexes demonstrates that groundwater quality has been declining over time.

This study was focused on identifying the region suitable for agriculture-based, using new irrigation groundwater quality plot and its spatio-temporal variation with fuzzy logic technique in a geographic information system (GIS) platform. Six hundred and eighty groundwater samples were collected during pre, southwest, northeast, and post monsoon periods. A new ternary plot was also attempted to determine the irrigation suitability of water by considering four essential parameters such as sodium adsorption ratio (SAR), permeability index (PI), Sodium percentage (Na %), and electrical conductivity (EC). The derived ternary plot was the most beneficial over other available plots, as it incorporated four parameters, and it differs from the US Salinity Laboratory (USSL) plot, such that the groundwater with higher EC could also be used for irrigation purposes, depending on the Na%. The ternary plot revealed that the groundwater predominantly manifested good to moderate category during post, northeast, and southwest monsoons. The assessment with the amount of fertilizer used during the study period showed that the NPK fertilizers were effectively used for irrigation during monsoon periods. Spatial maps on EC, Kelly's ratio, Mg hazard, Na%, PI, potential salinity (PS), SAR, residual sodium carbonate (RSC), and soluble sodium percentage (SSP) were prepared for each season using fuzzy membership values, integrated for each season. A final suitability map derived by an overlay of all the seasonal outputs has identified that the groundwater in the western and the eastern part of the study area are suitable for agriculture. The study recommends cultivation of groundwater-dependent short-term crops, along the western and northern regions of the study area during the pre-monsoon season.

The main purpose of this paper is to review on the effect of irrigation water quality and deficit irrigation on crop yield and water use efficiency. Low quality water for irrigation can impose a major environmental constraint to crop productivity. If salts become excessive, losses in yield will result. To prevent yield loss, salts in the soil must be controlled at a concentration below that which might affect yield. Irrigation application below the full evapotranspiration requirement is termed as deficit irrigation. Deficit irrigation consists of deliberately applying irrigation water in amounts below the plant's water requirements. Deficit irrigation can be applied at certain periods during the crop's growing season or throughout its growing season. Yield reductions also occur in a number of crops when subjected to water stress. Yield reductions depend on the crop's sensitivity to water stress at its various growth stages. In order for deficit irrigation to be an economically viable practice, the revenue lost due to yield reduction should be lower than savings in total cost of production. The goal of deficit irrigation is to increase crop water use efficiency by reducing the amount of water that is applied or by reducing the number of irrigation events. The interaction effects of water quality and DI illustrated that when the two types of stresses; saline and DI were coupled together, a serious reduction occurred on total dry biomass and total yield. The interaction effects of water quality and deficit irrigation illustrated that when the two types of stresses; saline and deficit irrigation were coupled together, a serious reduction occurred on total dry biomass and total yields.

Research Journal of Environmental and Earth Sciences 2(1): 44-48, 2010 ISSN: 2041-0492 © Maxwell Scientific Organization, 2009 Submitted Date: October 31, 2009 Accepted Date: November 24, 2009 Published Date: January 10, 2010 ... Corresponding Author: I. Anitha Mary, ...

Water Source is an important feature of all. In India, water sources like pond,
lakes, canals, etc. in many areas satisfy various demands i.e. manly irrigation and
other demands of drinking, etc., rearing and ground water recharge. In India, many of
water sources recently have been lost due to man-made activities and many of
remaining water sources are in stress due to risk of degradation. Throughout the
world, many water sources are effecting from various kind of pollutants from
industrial, urban and agricultural development. Water sources like canals, tanks and
ponds are well constructed to harvest rainwater for various local uses; it may be
drinking or agriculture purposes. Water sources serve many environmental functions
including flood and soil erosion control and are useful for irrigation, supply of
drinking water and ground water recharge. In this present study about 295 ground
water samples were collected in twenty four mandals, covering entire region of
Guntur District. To know the suitability and quality of ground water for irrigation
purposes parameters were analyzed as Electrical Conductivity, pH, Sodium
Adsorption Ratio, Residual Sodium Carbonate , Sulphates, , Carbonate, Bicarbonate,
Chloride, Fluorides, Iron, Zinc, Copper, Manganese, Nitrates and Ionic ratios of
Ca/Mg , Ca/Na, Mg/Na, Ca/SO4, Mg/HCO3 , and to suggested various required
control and management techniques to make water for better utilization

Hydrogeochemistry of groundwater was investigated to understand groundwater quality for drinking and irrigation purposes in an unconfined aquifer located in Jangal plain, NE Iran. Groundwater samples were collected and analyzed for determining physicochemical parameters (TDS, EC and pH) and concentration of major ions (Na + , K + , Ca 2+ , Mg 2 + , Cl − , HCO 3 − , SO 4 2 − and CO 3 2 −). Water quality assessment parameters including SAR, Na%, RSC, TH and SI were also calculated. TDS, EC, Na + , K + , Cl − and SO 4 2 − levels in all samples were greater than the maximum permissible limit, while pH, Ca 2 + , Mg 2 + and HCO 3 − levels in most samples were within the standard range. Based on the Piper diagram, most groundwater samples were classified into Na-Cl as dominant water type. The saline water intrusion, evapotranspiration, ion exchange reactions and dissolution of carbonate minerals were found as the main processes controlling the chemistry of groundwater. According to the calculated parameters and the Wilcox and USSL diagrams, high salinity and alkalinity of the groundwater resources pose a major problem for irrigation use. It is obvious that the groundwater unsuit-ability threatens sustainable crop production and soil quality. Hence, urgent management of groundwater resources is suggested to avoid harmful effects on inhabitants.