1. Introduction
The population of Bangladesh is increasing rapidly. The current population is 159 million but FAOSTAT projects that the number will increase to 185 million by 2030 and to 202 million by 2050 (FAOSTAT, 2016). Bangladesh has undergone tremendous changes in recent decades in terms of land use. This has affected the intensity of crop rotations. Urbanization and industrialization led to a decrease in the available land area for agriculture by approx. 0.25% annually during 1976–2010, and this rate is expected to continue in the future (BBS, 2011). Bangladesh also suffers regularly from several natural calamities (Haq et al., 2012), which