A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1985

The deep placement fertilizer applicator for rice from the international Rice Research Institute (IRRI) has been analysed for the drag force, and evaluated for its metering efficiency. It was found that the existing method of force application, ie. the push type is not an advisable one as far as the drag force is concerned. In pull type, among various hitching combinations tried the hitch point just below C.G of the applicator was found to be the optimum one. Also higher angles of pull caused large lift height of the furrow opener, hence it is suggested to keep the angle of pull small. The total force needed to pull at walking speed is not possible for a human labour to operate under non flooded conditions and within the capacity of a man under flooded conditions. Hence it is suggested that the applicator should be operated with a thin film of water in the field. Among the traction elements the skid absorbed max amount of pull. It absorbed about 40% of the total pull in flooded condition and 62% in non flooded condition, followed by the other parts, viz. the furrow opener 29% & 20% cage wheel 20% & 14% and furrow close 10% & 4% in flooded and non flooded conditions respectively. There is strong possibility of reducing the drag force by reducing the net moment about the centre of gravity (C.G) of the applicator. The spring auger is not an efficient device for metering prilled urea since the rate of application varied a lot in different work environment. Also there was no significant difference in metering between push and pull type.