Soil degradation during the period 1967–1995 in Bangladesh

Influence of soil type and properties on distribution and changes in arsenic contents of different paddy soils in Bangladesh

“…Based on the hydrological regimes, the soil samples were grouped into three land types: (i) highlands (above normal flood level), (ii) medium lowlands (flooded <1 m for <4 months), and (iii) lowlands (flooded> 1 m for >4 months), as shown in Table 3. A brief description of the study areas had already been reported (Ali et al 1997a).…”

“…This study was based on air-dried archived Bangladesh soil samples collected in 1967 and 1995, which were used in our previous studies (Ali et al 1997a(Ali et al -c, 1998 (Kawaguchi and Kyuma 1977), in the second (1995) sampling, the soils were collected similarly in June 1994 and April-May 1995 from the same sites / series as in 1967. Soil samples were collected from each individual horizon of the profiles.…”

“…The hydrological regimes are considerably influenced by the heterogeneity in the topographic elements and exert major impacts on the soils of the different landscapes in Bangladesh. Remarkable changes in cropping practices and the use of agricultural inputs, especially crop types, irrigation, and fertilizer application, were observed during the period between 1967 and 1995 in Bangladesh (Ali et al 1997a).…”

“…In our previous papers (Ali et al 1997a(Ali et al -c, 1998Wakatsuki 1998a, b, 1999), we described the changes in the general soil properties to assess soil degradation in Bangladesh. The results showed a general trend of nutrient depletion and indicated the need to implement measures to restore the biological productivity of these soils.…”

Distribution and changes in heavy metal contents of paddy soils in different physiographic units of Bangladesh

“…The hydrological regimes are considerably influenced by the heterogeneity in the topographic elements and exert major impacts on the soils of different physiographic units. Remarkable changes in cropping practices and the use of agricultural inputs, especially crop types, irrigation and fertilizer application, were observed during the period 1967-1995 (Ali et al 1997a(Ali et al , 2003.…”