Direct Seeded Rice
G.B.Pant University of Agriculture & Technology, Pantnagar-Uttrakhand
Transplanted rice has deleterious effects on the soil environment for the succeeding wheat and other upland crops. Direct seeded rice which removes puddling and drudgery of transplanting the young rice seedlings provides an option to resolve the adaphic conflict and enhance the sustainability of rice-wheat cropping system. Puddling requires lots of scarce water at a time when there is little water in the reservoirs, destroys soil structure and adversely affects soil productivity. DSR overcomes the problem of seasonality in labour requirement for rice nursery raising and transplanting operations.Non-development of ground water in kharif, late onset of monsoon and drudgery of operations often delays rice transplanting which leads to late vacation of fields, forcing farmers to plant wheat after the optimum sowing time. DSR facilitates timely establishment of rice and succeeding winter crops. Unlike puddle fields, DSR fields do not crack and thus help save irrigation water. Surface retained residue serve as physical barrier to emergence of weeds, moderate the soil temperature in summers and winters, conserve soil moisture, add organic matter and nutrients to the soil on decomposition.
Direct Seeded Rice
Rice can be directly seeded either through dry or wet (pregerminated) seeding. Dry seeding of rice can be done by drilling the seed into a fine seedbed at a depth of 2-3 centimeters. Wet seeding requires leveled fields to be harrowed and then flooded (puddling). The field is left for 12-24 hours after puddling, then germinated seeds (48-72 hours) are sown using a drum seeder. Seed can be broadcast for either dry or wet seeding, but manual weeding is more difficult. Indeed, weed management is a critical factor in direct seeding. Timely application of herbicides (timing is dependent on the method of seeding) and one or two hand weedings provide effective control.
- Plow the fields during summer to control emerging weeds
- Leveling the fields well facilitates uniform irrigation and better germination
- Minimum-till drill/Power tiller drill
- Zero-till drill
- Bed drilling
Seed depth and soil moisture
- Optimum depth of seed:2-3 cm. The seed should be covered by soil for proper germination and to avoid bird damage.
- In lowlands and finer textured soils, planking may not be necessary after seeding.
- Soil moisture content at seeding should be sufficient for proper germination
- Surface mulch: helps retain soil moisture longer to improve emergence and reduce weed menace
Seed rate and cultivars for DSR
- Seed rate:20 to 25 kg/ha, in general
- Fine grain and Basmati cultivars require much less seed
- Early to medium short duration cultivars having early vigor
- Tested cultivars are:Hardinath1, Sabitri, Sonamasuli,Radha11 and Radha4
- Drill the dry seed of normal rice at the start of monsoon i.e. when farmers put seed into nursery bed
- May 3rd week to June 2nd week (Jesth 1st week to Jesth 3rd week )
- Pre-germinated weeds can be knocked down with glyphosate/grammoxone (at 0.5% two days before seeding) or by 1-2 very shallow ploughings (stale seed bed method)
- Second flush of weeds can be removed manually
Benefits of Direct Seeded Rice
- Avoids repeated puddling, preventing soil degradation and plow-pan formation
- Facilitates timely establishment of rice and succeeding crops as crop matures 10-15 days earlier
- Saves water by 35-40%, reduces production cost by Rs 3000/ha, and increases yields by 10%
- Saves energy: labor, fuel, and seed
- Solves labor scarcity problem and reduces drudgery of labors
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