Purpose: In order to ensure that vegetable seedlings (with a soil block around their roots) are planted in an upright orientation after metering in a vegetable transplanter, they need to be dropped freely from a certain height. The walkbehind hand-tractor-powered machines do not have sufficient space to drop the seedlings from that height. In the present work, a hopper-type planting device was developed for the walk-behind hand-tractor-powered vegetable transplanter to ensure that the soil block seedlings are planted in an upright orientation. Methods: Various dimensionless terms were developed based on the dimensional analysis approach, and their effect on the planting of soil block seedlings in an upright orientation (planting efficiency) was studied. The optimum design dimensions of the hopper-type planting device were identified by the Taguchi method of optimization. Results: The ratio of the height of free fall to the sliding distance of the seedling on the surface of the hopper had the highest influence on planting efficiency. The planting efficiency was highest for plants with a height 15 ± 2 cm. The plant handling Froude number, in interaction with the design of the hopper-type planting device, also significantly affected the planting efficiency. Of the hopper design factors, the length of the slide of the seedlings on the surface of the hopper was most important, and induced sufficient velocity and rotation to cause the seedling to fall in an upright orientation. An evaluation of the performance of the planting device under actual field conditions revealed that the planting efficiency of the developed planting device was more than 97.5%. Conclusions: As the seedlings were fed to the metering device manually, an increase in planting rate increased missed plantings. The planting device can be adopted for any vegetable transplanter in which the seedlings are allowed to drop freely from the metering device.

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Six levels of energy input were used to cultivate three Sali paddy varieties of different durations. Operationwise as well as source-wise energy output, energy efficiency and energy productivity for different levels of energy input in paddy varieties were determined. Studies showed that with increase in the level of mechanization, the human and animal hour requirement for paddy cultivation was reduced from 795 to 350 and 352.5 to 22.5 hr/ha, respectively. Thus mechanization helped in a substantial reduction of drudgery of human and animals. Total energy requirement for paddy cultivation in the studied six levels of energy input ranged from 5630 to 8448 MJ/ha. Energy used in paddy cultivation could be reduced by 8 to 23% through increasing the level of mechanization. Under these six input energy levels and varieties, output parameters viz., output energy, energy use efficiency and energy productivity ranged from 35456 to 85922 MJ/ha, 5.94 to 13.09 and 0.4 to 0.89 kg/MJ, respectively. For all the levels of energy input, higher values of output energy parameters were observed in the long duration variety Ranjit compared to other two varieties. The benefit-cost (B:C) ratio under different levels of energy input varied from 0.95 to 2.90.

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