Bangladesh’s economy is heavily dependent on agriculture. It is beyond question that the rice industry has an overwhelming influence on the national economy. Bangladesh is now essentially self-sufficient in rice, its basic cereal, and is emerging as a significant exporter of high-value agricultural products (USAID Bangladesh, 2006). There has also been a sharp increase in the use of inorganic nutrients, i.e., chemical fertilizers, to get a higher yield from modern varieties of rice. During the green revolution, for example, 1 kg of added nitrogen fertilizer would produce 20 kg of grain, but now it only produces 8 to 10 kg (FAO, 2004). Declining productivity due to soil degradation is now a major constraint. It is said that a good soil should have an organic matter content of more than 3.5%, but in Bangladesh most soils have less than 1.7%, and some soils
have even less than 1% organic matter (BARC, 1997). Moreover, the continuous and unbalanced use of inorganic nutrients in an intensive cropping system has been considered to be the main cause for stagnating or declining crop productivity. Unless the use of balanced fertilizers and organic matter in soils is seriously considered, sustenance or an increase in productivity can hardly be achieved.