ABSTRACT
The salinity is considered an important limitation for the production of food grains in coastal areas of the
country. It causes adverse environment and hydrological situation that limit normal crop production
throughout the year. The effects of salinity are considered also to be one of the most serious threats to the
environment possible negative effects on food security, agriculture, fisheries, human health, biodiversity,
water, and other natural resources. The aim of the present research study was therefore to know the salinity
levels in surface water for irrigation purposes. The study was conducted with the five water samples from
adjacent surface water sources at Polder 33. Water samples collected from adjacent khals (cannels) were
analyzed against National/International permissible limits for irrigation water quality. The analytical results
showed that in 2007 the salinity varied 1.07-1.61 ms/cm, while 1.57-2.01 ms/cm in 2008. Here the highest
salt content was measured from Borobaker khal during 2007 and on the other hand in Dhopar khal during
2008. The findings also showed that the salt content was always increased except Borobaeker khal. The
variations were measured in the range of 16.30-62.10%. The results for salinity in different khal water of
Polder 33 also explored that the salinity levels were within the permissible limit accordingly the different
existing national as well as international standards for irrigation water. Hence the water can be used to grow
crops safely in the coastal Dacope Upazila of Bangladesh.
Key words: Salinity, surface water, coastal, polder.
Introduction
The coastal area covers about 20% of the country and over 30% of the net cultivable area. It extends inside
up to 150 km from the coast. Out of 2.85 million hectares of the coastal and offshore areas about
0.83 million hectares are arable lands, which cover over 30% of the total cultivable lands of Bangladesh.
Most of the coastal areas of Bangladesh are used in agriculture. The cultivable lands in these coastal areas
are affected with varying degrees of soil salinity and other natural hazards (SRDI, 2013). In the south-west
coastal zone of Bangladesh, frequent natural disasters like- flood, cyclone, and associated storm surge,
water logging, river erosion etc are familiar phenomena. Super cyclones like- SIDR (2007), and AILA
(2009) increased soil salinity that hampered agriculture, the major livelihood of this area. The farmers of
the coastal belts mostly cultivate rice and at the same time they grow some indigenous vegetables like
cucumber, tomato, cantaloupe/rock melon, spinach, cabbage, broad bean, potato, sweet potato, capsicum,
beans, carrot, radish, sweet gourd, bottle gourd, red amaranth, aroids etc. In this area, crop performance
may be adversely affected by salinity-induced nutritional disorders. Salinity influence the nutrient
availability, competitive uptake, transport or partitioning within the plant or may be caused by
physiological inactivation of a given nutrient resulting in an increase in the plant’s internal requirement for
that essential element. Two or more of these processes may occur at the same time, but whether they
ultimately affect crop yield or quality depends upon the salinity level, composition of salts, the crop
species, the nutrient in question and a number of environmental factors (Grattan and Grieve, 1999). In some
cases, salinity also has a toxic effect on plants because of the high concentration of certain salts in the soil.
Salinity prevents the plants from taking up the proper balance of nutrients they require for healthy growth.
Land use of south-west coastal Dacop of Khulna is diverse, is competitive and conflicting. Agriculture,
shrimp farming, salt production, forestry, ship breaking yards, ports, industry, settlements, and wet lands
are some of the uses. Due to climate change the adaptation strategies of costal agriculture also have been
changed now a day. There are different adaptation options introduced for agricultural activities which
enhancing agricultural production, improve soil health. As soil salinity in coastal zone particularly Dacop