The study was carried out in Rajshahi district of Bangladesh from December 2000 to February 2001 at eight villages under four Upazilas (i.e. sub-districts) namely, Atghori and Chatari village under Bagha Upazila, Baladiar and Charghat village under Charghat Upazila, Dhokrakol and Nokulbaria village under Puthia Upazila, and Hatisail and Dhantere village under Tanore Upazila. Rajshahi district is located between 24°07´ and 24°43´N latitude and between 88°17´ and 88°58´E longitude (Anon, 1991a). It covers Tropical monsoon climate like other parts of Bangladesh. It rains about 90% of the total rainfall in the rainy season. The mean maximum and minimum temperature is 35.3°C in April and 11.2°C in January respectively. The annual rainfall in winter, pre-rainy and rainy season is 46 mm, 232 mm and 1,276 mm respectively (Anon, 1996a). Topography of the four Upazilas is more or less plain in nature and is included in Ganga river floodplain area (Anon, 1996b). The field survey was conducted at the more or less same type of site factors for cropland agroforestry, homestead agroforestry and annual cropping practice to compare them in different aspects.
The sample size was 150 including 50 samples (plots) for cropland agroforestry, 50 samples for homestead agroforestry and the rest 50 sample plots for annual cropping system from the four Upazilas. The pre-mature and matured agroforest were surveyed. The agroforestry program of the region is in young stage. The sampling units were selected from the field by some stages because of the uneven and discrete distribution of agroforestry plot in the region. At first four Upazilas from Rajshahi district were selected purposively depending on the availability of agroforestry type of landuse. Then, two unions from each Upazila were selected randomly, after that one village from each union and finally, a required number of farm households were selected randomly for sampling. Two sets of diagnostic semi-structured questionnaire were surveyed for conducting the survey. One is for cropland agroforestry or pure agricultural crops on agricultural land. The second one was for homestead agroforestry survey. Only Benefit-Cost Ratio (BCR) method of profitability measurement has been used here due to unavailability of the required data which is necessary for calculating the other methods.
Labour cost has been divided into market price cost and opportunity cost which includes establishment (such as field preparation, fencing, etc.), maintenance (weeding, Irrigation, fertilizer and pesticides) and harvesting cost. Capital includes seeds, equipments or tools, ploughing, fertilizer (organic and inorganic), pesticides, Irrigation, fodder, stacking, marketing and other cost. After getting the total costs it is then compounded at 6% interest rate by using the compounding formula (FVn = PV(1+i)n Where, PV = Present value, i = Discount rate, FVn = A future value in year n, n = The number of years). For benefits, items such as food, fuel, fodder, timber and pole or post have been considered. Then calculating the total benefits, it is compounded at 6% rate of interest. Finally, the BCR is calculated by dividing the compounded benefits by compounded costs. The calculation has been done on the basis of per acre area per year basis.