Abstract
A power tiller operated combined tillage bed former and seeder was developed in Farm Machinery and Post- harvest Process Engineering Division, Bangladesh Agricultural Research Institute, Gazipur. There were three sizes of bed former and the sizes were 60 cm, 70 cm and 120 cm. The bed former and seeder consists of main four functional components, namely, a) high speed rotary tiller, b) bed former, c) seeder and d) soil compaction roller-cum-shaper. No prior land preparation is needed for application of the bed former. In the first pass of operation of bed former, good quality of beds were formed with 80% efficiency. In the second but final pass of operation, bed forming, seed sowing, covering and soil compaction were done simultaneously. Top width of 60 cm, 70 cm and 120 cm beds were 28 cm, 35 cm and 87 cm, respectively. Furrow width and depth were 30 cm and 12-15 cm, respectively. In case of reshaping old beds, seed sowing, covering and soil compaction were done simultaneously in a single operation. For making only beds for transplanting vegetables or any other crops, seed sowing arrangements were removed from the bed former or kept it off. Field performance test of the bed former was done to make the machine perfect. Seed rate of different types of seeds like wheat, mungbean, rice, sesame and maize were calibrated in the laboratory. The maximum and minimum seed rates were calibrated by adjusting the roller length of seed metering device. For field performance test, the bed former of 60 cm size was used for sowing wheat, mungbean and sesame at the seed rate of 90 kg, 30 kg and 3 kg per ha, respectively. Two rows of seeds were sown on beds at 20 cm row spacing. For maize, 70 cm size bed former was used and single row of seed was planted on bed. After harvesting wheat, the same beds were used for sowing mungbean and sesame. After mungbean, the beds were used for transplanting aman rice without land preparation (zero tillage). The bed formers were also used for vegetables production. For sowing radish, carrot, kangkong and amaranth, 70 cm size bed former was used. After harvesting winter vegetables, the same beds were used for summer vegetables production by reshaping the beds. For sowing small seeds like sesame, radish, carrot and amaranth, rice bran was mixed with seed at the ratio of 2:1 (by volume). Field capacities of 60 cm, 70 cm and 120 cm bed formers were 0.11, 0.15 and 0.20 ha/h, respectively. Field efficiency of 60 cm, 70 cm and 120 cm bed formers were 82%, 85% and 83%, respectively. Operation cost of 60 cm, 70 cm and 120 cm bed formers were Tk. 1,198.62, 910.79 and 694.05 per ha, respectively. Operation cost of 120 cm size bed former was 58% less compared to 60 cm size bed former due to double width of operation. Break-even-point of 60 cm, 70 cm and 120 cm size bed formers were 4.83 ha and 3.27 ha, respectively. Cost of combined tillage bed former and seeder was Tk 26,933 without power tiller. Power required to operate the 60 cm size bed former in clay soil was 2.92 kW and sandy loam soil was 2.73 kW. Production costs of different crops were less when the bed former was used. Gross return, gross margin and benefit-cost ratio were higher in bed planting method than the conventional method. The developed power tiller operated combined tillage bed former and seeder was a simple, low cost and affordable conservation tillage-cum-sowing machine for the farmers of Bangladesh.