Manually Operated Aerobic Rice Drum Seeder

In legend and religion around the World, rice is regarded as a precious gift of God to the Earth. For most Asians, rice is the staple food. Modern agriculture gives greater emphasis on increased production per unit area per unit time leading to exploitative agriculture. It has become imperative to increase the productivity and also to sustain higher productivity through aerobic rice cultivation. The term "Aerobic rice" means growing high yielding rice varieties in non-puddled and non-flooded aerobic soil. Aerobic cultivation entails the growing of rice in aerobic soil, the method of sowing is important.

Direct seeding and transplanting are two general methods for planting rice. The primary difference between the two methods is that in the transplanting method, seedlings are first raised in the seedbed before they are planted in the main field whereas in direct seeding, the seed is sown directly in the main field either by broadcast seeding in wet or dry field. Drill seeding in dry soil makes the use of mechanical seed drills feasible. It improves soil structure since puddling in minimized. Lower labour cost is the major advantage of direct seeding. This method eliminates scedbed preparation. care of seedlings in the seedbed. pulling seedlings and hauling and transplanting operations. The savings in labour may substantially reduce production cost. particularly in areas where labour cost is high. Also directly seeded rice may mature 7 to 10 days earlier than transplanted rice. This saving in time is important especially where multiple cropping pattern is used.

Weeding is a problem if broadcast seeding is used. The weeding problem is less in row seeding because it allows the use of mechanical weeders. This is true, especially in countries where chemical weed control is not yet widely practiced due perhaps to the fact that herbicides are too expensive for the ordinary farmer. Direct seeded rice also have a greater tendency to lodge than transplanted rice because roots of directly seeded rice develop poorly and anchorage is poor. International Rice Research Institute (IRRI) researchers are of the opinion that there is no significance difference in yield of transplanted or directly seeded rice if good management practices are used with each method.

The problem in direct seeding is to devise suitable methods which would reduce the labour problems during peak seasons. For accomplishing the timeliness of operation an attempt was made to develop a manually operated aerobic rice drum seeder. The design of drum seeder should be based on ergonomic consideration to make it comfortable to the operator. The planted rice seeds should achieve an acceptable germination percentage, using local rice variety under garden land conditions.

Construction

A manually operated aerobic rice drum seeder unit consists of the functional components such as seed drum, furrow openers, furrow closer, ground wheel and handle.

Seed drum: The seed drum of optimized shape i.e., hyperboloid (truncated cone) with 20 cm diameter was fabricated with 12 mm flat spikes of 25 mm length kept parallel to the axis of rotation. The slopes of the cone facilitate the free flow of seeds towards the metering holes. Nine numbers of seed metering holes of 10 mm diameter were provided along the circumference of the drum at both the ends for a row-to-row spacing of 20 cm. The drums for the prototype were fabricated with the optimized values of variables using plastic sheet provided with 25 mm diameter plastic bushes on either sides.

Main shaft: The main shaft of the aerobic drum seeder consists of a 25 mm mild steel pipe of thickness 1.5 mm to accommodate the three seed drums and ground wheel.

Ground wheel: Seed drums are rotated by the motion of the ground wheel without slippage to get a uniform and desired seed rate. Ground wheel of 60 cm diameter was fabricated by using 18 mm diameter mild steel pipe and 25 mm internal diameter wheel hub for mounting the wheel on the main shaft. For better traction, 12 numbers of lugs made of 22 gauge galvanized iron sheet were welded on the inner periphery of the wheel.

Furrow openers: Furrow openers were provided with the drum seeder to make the seeds to fall on opened furrows and to avoid the scattering of seeds. They were made of 22 gauge galvanized iron sheet. The furrow openers were mounted on a 12 mm mild steel plate and connected to the main shaft by inserting the pipe into a pin welded to 25 mm pipe bush on the main shaft. The position of the opener was set to mark a furrow on the soil surface. The depth of furrow can be adjusted by the position of bolt and nut on the travel hole of the furrow opener.

Furrow closer: After the seed fall, the furrow closer is used to slightly and gently close the seeds with soil without disturbing their position. The flat rod type furrow closers are mounted on 12 mm mild steel pipe and connected to the main shaft by inserting the pipe into the main shaft.

Handle: The handle of the drum seeder is made of 18 mm mild steel pipe and hitched to the main shaft by 25 mm mild steel pipe bushes. The height of the handle from the ground level can be adjusted by using the holes provided in the main handle frame depending on the height of the operator.

The performance of the manually operated aerobic rice drum seeder was designed, evaluated and the performance of the machine found out. The results of the study indicated that wedge type furrow opener gave satisfactory performance and its operation was free from clogging. An average seed was placed at 17 mm depth with a row-to-row spacing of 20 cm. Ground wheel of 600 mm diameter with 24 external lugs, 90o lug angle offered 8.53% slip. The power requirements to pull this seed drill were within the capacity of an average man (0.0746 KW). The field capacity of the drum seeder was 0.114 ha/h at the speed of 1.0 km/h under dry soil condition. The rate of seed requirement was 35 kg/ha and grain yield of aerobic rice 4.35 t/ha. The PMK 3 rice variety seed was achieved very well in aerobic rice cultivation practices. The seed rate was 42 and 56% as compared transplanting and manually broadcasting methods.

Source: Invention Intelligence