Impacts of Topsoil and Surface Water Salinity on Agriculture: A Study at Paikgachha, Khulna

Abstract

The study investigates top-soil and surface water salinity and its impact on farming practices. Sholadana Union of Paikgachha Upazila under Khulna district is selected for the study, where there is an increasing dominance of shrimp farming aquaculture. The study is based on primary data collected through field survey and laboratory analysis of soil and water samples in two different time periods (May and September), household questionnaire survey, Focus Group Discussions (FGDs) with key stakeholders and salinity data of both soil and water collected from Soil Resource Development Institute (SRDI). Both soil and water salinity levels were tested through chemical analysis in the laboratory. The study shows that salinity level has been increasing over the years. Dry season salinity in both water and soil remain high in May (31.1 dS/m and 16.09 dS/m respectively), while in September 1.4 dS/m and 0.3 dS/m respectively. Dry season salinity is extremely higher than the standard level (<0.75 dS/m). Due to the increased salinity level, significant impacts have been observed in farming and freshwater aquaculture practices, such asloss of soil fertility and decreasing rice productivity and loss of freshwater species etc. Though salinity level remains favourable to farming practices in wetter months, stagnant of surface water elsewhere becomes an impediment. However, to maintain salinity level for both soil and water for farming and freshwater aquaculture, any further conversion of farming lands into shrimp ponds should be stopped.