Selection of study location Jessore is one of the greater districts of Khulna division, which is located in south west of Bangladesh. Jessore, is situated between 22°10´ and 22°28´ east longitudes and in between 89°16´ and 89°64´ north latitudes, is in directly proximity of Jessore Domestic Airport, and the area is nearly slope from north to south. The Jessore district encompasses of 2,606 km2 , 7m elevated from sea level and the Jessore town is situated on the bank of Bhairab river. It is characterized by intense urbanization and several industrial sites. It is also distinguished by a high distribution of agricultural areas, and is therefore classified as an urban agriculture area. Abhaynagar is situated between 23"07' and 23"15' north latitude and in between 89"18' and 89"34' east longitudes of Bangladesh, is predominantly agricultural, and is intermediate between urban and rural areas with no industrial sites or heavy urbanization, and was therefore, classified as a peri-urban agricultural area. The chemical composition of agricultural field soil and surface water like pond, lake and river waters is a major factor in determining its quality and hence, the chemical analysis of soil & surface water samples is necessary to assess the concentration of water toxicity on human health, crops and livestock. An attempt has been made to analyze soil & water samples collected from the entire Jessore & Abhaynagar (urban & peri-urban) area and the chemical analysis of soil and water samples included the concentration of Pb, Cd, N, P, K, OM, EC and pH of all collected samples.
Selection of sampling units To perform the environmental analysis based on agricultural land use type basis, the Industrial area, High rise building area, High way road area which represents high urbanization were chosen. These units are randomly selected from the urban and peri-urban area. In Jessore district and Abhaynagar thana, 3 sampling units were selected within each agricultural land use type, to evaluate soil and water quality. However, to study the floristic biodiversity, Jessore and Abhaynagar were chosen. Here, total of 6 sites were selected, and collected in two consecutive seasons (3 sampling units each), one accounting for Kharif (2013) and the other for Rabi (2014) floristic diversity.
Collection of Soil and water samples Composite samples were obtained using the random sampling method for field soil sampling (Ryan et al., 1996) from each sampling site chosen in both locations; Jessore and Abhaynagar, within the three land use types. The samples were obtained from a depth of approximately 0-15cm (Richards et al., 1998). This was performed to enable the differentiating between long-term and short-term effects of agricultural practices on soil quality to determine the magnitude of the impact on the environment. Adjacent areas demonstrate the soils ability to return to its baseline levels were in a short period of time relative to that or the urban and natural land use types. Therefore, from the each sampling sites in industrial area, high rise building area and high way road site in Jessore and Abhaynagar, total 60 samples (30 water & 30 soil samples) were obtained respectively with 5 replications in 6 urban and 6 peri-urban areas.
Organic matter content Organic matter content was determined using the Wet Combustion Method. This procedure for measuring the organic matter content of the soil samples involves the reduction of potassium dichromate (K2Cr2O7) by organic carbon compound and subsequently determining the unreduced dichromate by oxidation-reduction titration with ferrous sulfate (FeSO4). For every soil sample collected, 10mL of potassium dichromate (K2Cr2O7) solution and 20mL of concentrates sulfuric acid (H2SO4) was added to 2g of soil. After standing for 30 minutes 200mL of distilled water and 10mL of phosphoric acid (H3PO4) were added and left to cool. Using diphenylamine indicator, the mixture was titrated with ferrous ammonium sulfate solution until the color changed from violet-blue to green. The organic matter content was calculated by multiplying the content the organic carbon by Van Bemmelen factor 1.73