Agricultural losses caused by salinity are difficult to assess but estimated to be substantial and expected to increase with time. Secondary salinization of agricultural lands is particularly widespread in arid and semiarid environments where crop production requires irrigation chemes. At least 20% of all irrigated lands are salt-affected, with some estimates being as high as 50%. Whereas the world’s population continues to rise, the total land area under irrigation appears to have leveled off. The need for increased food production therefore needs to be met by increases in yield per land area. To reach this goal, genetic engineering of crop plants for enhanced salt tolerance will be a very important approach. In dry regions where fresh water becomes a scarce commodity, irrigation of moderately salt tolerant crops with brackish water is feasible. Transgenic lines of some crop species have been generated which can grow and develop at fairly high salinity levels in controlled environments. These transgenics must be tested vigorously for yield potential under field conditions.

Global Impact of Salinity and Agricultural Ecosystems

http://directory.umm.ac.id/Data%20Elmu/jurnal/A/Agricultural%20Water%20Management/Vol45.Issue3.Aug2000/1579.pdf

Integrated water management: emerging issues and challenges

The purpose of this chapter is to provide plant scientists with a background on the nature of soil salinity with a particular emphasis on irrigated agriculture. Since the chemistry of soil solutions plays a major role in soil salinity, considerable details on this topic are offered. Chemical speciation in the soil solution should be of importance to plant scientists. The dynamic nature of soil salinity in the rootzone affects performance of plants. Profile distribution of salts is affected by leaching fraction and changes with changing water content from irrigation and rootwater extraction. Soluble salts in soils are highly mobile and transported by water through mass flow and dispersion. Irrigation water management is one of the keys in maintaining salt balance in the rootzone. Growing regulations on the disposal and management of poor quality drainage waters is now exacerbating the maintenance of salt balance in the rootzone in irrigated lands.

Salinity in the Soil Environment

Irrigation development in the arid zone almost alwayshas to deal with not only secondarysalinity but also with primary and fossilsalinity. In many cases, irrigationdevelopment brings about large scalechanges in the local geohydrological regimewhich often result in mobilization of saltsstored in the underlying substrata. Thisprimary and fossil salt mobilization hasbeen found to be one of the principalcauses of rivers salinization in irrigatedbasins in the arid zone. The paperhighlights this hitherto insufficientlyrecognized salinity hazard and discussesrelated control measures and strategies.

Irrigation and salinity: a perspective review of the salinity hazards of irrigation development in the arid zone

Multivariate statistical techniques, such as cluster analysis (CA), principal component analysis, and factor analysis, were applied for the evaluation of temporal/spatial variations and for the interpretation of a water quality data set of the Behrimaz Stream, obtained during 1 year of monitoring of 20 parameters at four different sites. Hierarchical CA grouped 12 months into two periods (the first and second periods) and classified four monitoring sites into two groups (group A and group B), i.e., relatively less polluted (LP) and medium polluted (MP) sites, based on similarities of water quality characteristics. Factor analysis/principal component analysis, applied to the data sets of the two different groups obtained from cluster analysis, resulted in five latent factors amounting to 88.32% and 88.93% of the total variance in water quality data sets of LP and MP areas, respectively. Varifactors obtained from factor analysis indicate that the parameters responsible for water quality variations are mainly related to discharge, temperature, and soluble minerals (natural) and nutrients (nonpoint sources: agricultural activities) in relatively less polluted areas; and organic pollution (point source: domestic wastewater) and nutrients (nonpoint sources: agricultural activities and surface runoff from villages) in medium polluted areas in the basin. Thus, this study illustrates the utility of multivariate statistical techniques for analysis and interpretation of data sets and, in water quality assessment, identification of pollution sources/factors and understanding temporal/spatial variations in water quality for effective stream water quality management.

Assessment of surface water quality using multivariate statistical techniques: a case study of Behrimaz Stream, Turkey

Management of agricultural drainage water quality , Management of agricultural drainage water quality , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Lyman S. Willardson

Papers

Management of Agricultural Drainage Water Quality