Soil Fertility Status of Major Tobacco Growing Lands of Bangladesh

Abstract

Tobacco cultivation is associated with the destruction of soil quality, productivity, and environmental pollution. An experiment was conducted to know the soil fertility status of tobacco and non-tobacco growing soils of major tobacco growing areas (Manikganj, Kushtia, Lalmonirhat, Nilphamari, Chattogram, Rangamati, Bandarban and Khagrachari) of Bangladesh. Soil samples were examined to check the level of various nutrient components of soil like Organic Carbon (OC), Nitrogen (N), Phosphorus (P), Potassium (K), Zinc (Zn) in the Laboratory of Soil Science at Bangladesh Institute of Nuclear Agriculture. Wet oxidation, Kjeldhal, Olsen, flame photometer and atomic absorption spectrophotometer methods were followed to determine the OC, total N, P, K and Zn respectively of the soil samples. Overall, the results showed a decrease in all the nutrients in the tobacco growing lands compared to non-tobacco growing lands. The amount of OC (p value 0.0271), total N (p value 0.0162) and exchangeable K (p value 0.0006) were significantly lower in the tobacco lands. The organic carbon content of both tobacco and non-tobacco land showed below standard limit (2%). The total nitrogen content of the soil samples for both tobacco and non-tobacco showed below 0.5% except the non-tobacco growing lands of Chattogram and Khagrachari. The available P and Zn content in tobacco lands also showed a decrease in compared to non-tobacco lands but statistically there were no significant differences between them. The available P and Zn content in all the soil were below 50 ppm (except Khagrachari in non-tobacco lands) which was very low. The K content was also low in the tobacco growing lands and low to medium in the non-tobacco growing lands. This result reveals the poor soil condition due to tobacco cultivation in the major tobacco growing areas of Bangladesh. So, effective measures should be taken immediately to retain the soil health.