Design and development of precision planter for Paddy direct seeding

A study was undertaken to design and develop a precision planter for direct seeding of paddy to overcome the problems faced in direct seeding with respect to seed rate and spacing. Physical and engineering properties of paddy seeds of three varieties (PUSA-1121, PUSA-44 and BPT-5204) representing long, medium, and small-sized paddy seed were used for selection of design values of planter components. Based upon laboratory performance, an optimum size metering plate, forward speed of operation, and angle of inclination were selected; and a prototype of a tractor-drawn 9-row precision paddy planter with electronic metering was developed. Performance results indicated a mean seed spacing of 150.1 mm (closer to recommended 150 mm), 90.5 % highest quality feed index, 5.7 % lowest miss index and 6.2 % multiple index, minimum seed damage of 0.38 % and optimum seed rate of 20.15 kg.ha⁻¹ (closer to recommended 20 kg.ha⁻¹) at a forward speed of 2.0 km.h⁻¹ and 350 angle of inclination of slanting-type cells. The breakeven point and payback period of the prototype precision planter were 95 h.year⁻¹ and 2.5 years, respectively, and were close to that of mechanical planter (88 h.year⁻¹ and 2.3 years, respectively).