Direct Seeded Rice

Main field preparation

For preparation of the main plot, the following points should be kept in mind:

• Field should be prepared thoroughly by ploughing with desi plough 3-4 times followed by harrowing and planking. Ploughing should be started at least 2-3 weeks ahead of seeding so that weeds are dried up/decayed.
• The ploughing intervals should be spaced in such a way that the weeds that germinate after the first round are knocked down in the next round. This facilitates the stale seed-bed for seeding of the crop.
• If available, apply compost or manure uniformly prior to field preparation and mix well with soil.
• Repair the bunds to reduce water losses from the field during the cropping season.
• Level the fields with leveler before sowing.
• The basal fertilizer MOP and ZnSo4 dose is applied to the field with last ploughing (see fertilizer dose in fertilizer section below).
• Sufficient moisture required at sowing time for good germination.
• Plot size should be kept ideally as the per resources and irrigation availability. Ideally plot size (2000 sq. meter) is helpful in irrigation management.

Seeding machine:

A multi-crop planter fitted with inclined plate seed metering mechanism and depth control wheel (DSR-drill) is used for precise seeding and fertilizer placement.

Planking:

In dry DSR, a heavy pre-seeding planking is required to conserve the soil moisture intact in the soil for maintenance of proper depth and improve seed to soil contact resulting in better and uniform germination. Light post-seeding planking may be required to cover the bare seed. Nowadays, seed drills are fitted with spring-loaded wheels /flappers / chains attached behind the tines, which improve the proper seed to soil contact and seed coverage. In such case, post-seeding planking is not required. Sowing should be done in rows 20-25cm apart at a depth of 2-3cm using a seed rate of 35-40 kg/ha depending upon the variety, seeding machines, soil type and quality of the seed. As seed depth is critical to successful establishment, adjust depth control / setting wheels to ensure correct seed depth. Both very shallow and deeper depths are risky for crop emergence.

Field should be prepared thoroughly by ploughing with desi plough 4 times followed by harrowing and planking. Ploughing should be started at least 2-3 weeks ahead of seeding so that weeds are dried up/decayed. Alternatively, one pass of mould board plough followed by one or two passes of modified helical blade puddler are sufficient for obtaining good quality puddled soil. The ploughing intervals should be spaced such that the weeds germinating after the first round of ploughing are knocked down in the next round.

If available, apply compost or manure uniformly prior to field preparation and mix it well with soil.

• Repair the bunds to reduce water losses from the field during the cropping season.
• Level the fields, best by maintaining a shallow water layer in the field.
• The basal fertilizer dose is applied to the field (see fertilizer section below).
• Also keep the plot size ideal as per the availability of resources and irrigation access.

Seeding:

The direct seeding under wet condition i.e., Wet-DSR is accomplished with the help of drum-seeder. For drum-seeding, ideally the field should be saturated, but there should be no stagnating water. Excess moisture / water leads to decay of seed. A thin layer of water is helpful in improving the seed to soil contact.

For DSR, the fertilizer recommendation in Sali season is 60-20-40-5 and in Early Ahu/Boro season 60-30-30-5 kg/ha of N-P2O5-K2O-Zn. Nitrogen is applied into 3 splits i.e. 1/3 at 15 days after emergence, 1/3 at maximum tillering, and 1/3 at panicle initiation. In addition to this, if submergence occurs during Sali season, 20 kg N and 20 kg K₂O is applied 5-7days after recession of flood to facilitate regeneration, and boost recovery from flood-shock. The detailed schedule and method of applying all nutrients is given in the table.

Table 1: Fertilizer doses (kg/bigha) in Sali and early Ahu season

Note:

• Stop urea broadcast, in case bacterial blight symptoms appear.
• Apply ZnSO₄ in soils deficient in Zinc, once in three years.
• Never use urea in seed-drill while seeding, otherwise it will hamper seed germination and be corrosive to the instrument.
• As far as practicable, drain out standing water before top-dressing of fertilizer.

Keep the field weed-free, especially early in the crop season. Weeds do most damage in the early crop stage, but later control is also important to prevent seed setting by the weeds.

The drum seeder for wet direct seeding of rice (Wet-DSR)

Drum Seeder is one of the revolutionary equipment that changed the face of sowing paddy seeds in wetland fields. Direct seeding through drum seeder has eliminated the need of transplantation and hours of backbreaking manual work of the farmers while transplanting the rice seedlings in the main field. At one stretch with single operator effort, it covers 8-12 rows spaced at 20 cm at a time. The plastic frame of the drum seeder makes its working easy.

Parts of the drum seeder

• The seed drum is hyperboloid shaped with 200 mm diameter. There are eight seed metering holes of 9 mm diameter. Baffles are provided inside the seed drum between the seed holes to ensure the uniform seed rate in operation as well as to ensure hill dropping of the seeds. Each seed drum has two rows of planting, and 4-6 drums are assembled to form 8-12 rows of planting at single stretch.
• Wheels are provided at both ends. These wheels are made up of plastic material to provide floating characteristics. Wheel diameter is 2 feet.
• One handle base, one handle, and 4-6 seed drums are assembled with the square shaft. The handle is meant to pull along.

Operation procedure

• After assembling, fill the drums with pre-germinated seeds. Remember only two-third of the drums are to be filled at a time.
• Close the mouth with the knob provided.
• Pull the seeder manually at a normal walking speed (1 Km/h) in the backward position
• The wheel impression in the first pass will serve as a marker.
• In the second pass, one of the wheels should pass on the same wheel impression of the previous pass to maintain the row-to-row spacing of 20 cm.
• Occasionally, watch the dropping of the seeds through the holes of the seeder.
• Refill the drum when it reaches one fourth capacity.
• Continue the seeding operation.

Salient features

• Labor cost is reduced drastically.
• Uniformity in seed sowing and plant population.
• Continuous drilling of seeds is eliminated.
• Reduction in seed rate and thinning cost.
• Crop matures 7-10 days earlier than transplanted paddy.
• Light in weight and easy to handle.
• An area of 1 hectare can be sown in a day.
• Under rainfed ecologies of Assam, where dry-DSR is having limited scope, Wet-DSR is a cost-effective alternative solution for crop establishment.

Specifications

Multi-crop planter (DSR-drill) for dry direct seeding of rice

Multi-crop planter fitted with inclined plate seed metering device and fertilizer dropping attachment distributes the seed and fertilizer uniformly and is ideal to be used under dry conditions at a controlled depth adjusted through depth control wheels pre-fitted with the machine.

Major components

Parts of the machine:

1. Frame, 2. Furrow openers, 3. Tres, 4. Fertilizer box, S. Seed box, 6. Chat and gear drives, 7. Drive wheel, 8. Depth control wheel, 9. Fertilizer delivery pipe, 10. Seed pipe, 11. Fertilizer rate adjusting nut, 12. Seed rate adjusting strip

• Requires lower seed rate
• Optimum seeding depth
• Maintains spacing between the rows
• Uniform seed rate throughout the field
• Good soil and seed contact, improved germination
• Provides option for drilling the basal application of granular fertilizers
• Conducive for intercultural and plant protection measures
• Better yield and more profitable than broadcast sowing
• Labor saving (as compared to transplanting)
• Environment friendly
• Brings opportunity to run business as ‘service provider’
• Also leads to positive impact on the productivity of succeeding crop.