Package of rice production practices for different systems of rice cultivation are briefly presented:
1. Wet (Irrigated) System:
Varieties:
A large number of improved varieties/hybrids have been developed to suit various agroclimatic zones in different states of the country. High yielding varieties are also available for problem soils, resistance/tolerance to pests and diseases.
Tillage:
1. Summer plowing and harrowing.
2. Puddling and perfect land levelling.
Nursery Management:
1. Adopt the seeding density in nursery using only 40 g seed m-2 to produce thick, robust and healthy seedlings.
2. Apply 100 N, 20 P2 O5 and 20 K2 O kg ha-1 to nursery for producing healthy seedlings. Correcting zinc and phosphorus deficiency in the nursery also is beneficial.
3. Seedling root dipping in Dursban (Chloropyriphos) solution (0.02%) before planting helps in controlling rice whorl maggot, stem borer etc.
Time of Planting and Crop Geometry:
1. Kharif:
Early planting in July with 20 x 15 cm spacing, using 20 to 25 days old seedlings (around 30 days seedling can be used for medium and long duration cultivars).
2. Rabi:
Early January with 15 x 15 cm spacing using 20 to 25 day old seedlings.
Fertiliser Management:
1. A blanket dose of 40 to 60 kg N ha-1 is adequate for fertile delta soils as against 80 to 100 kg of N ha-1 for low fertility light soils during kharif. A blanket basal dose of P2 O5 and K2 O at 40 kg ha-1 each is required.
2. For rabi rice, the blanket N dose for fertile soil is 80-100 kg ha-1 as against a higher dose of 100 to 120 kg N ha-1 for low fertility soils. Recommended blanket dose of P2 O5 and K2 O is 50 kg ha-1 each at planting.
3. For medium and long duration cultivars, N has to be applied in 3 splits (50% basal, 25% at active tillering and 25% at PI). Two splits (50% basal and 50% at PI) could be adequate for short duration cultivars on heavy soils.
4. Nitrogen has to be applied in the form of organics (green manuring with dhaincha, FYM, Azolla etc.) and chemical fertiliser (prilled urea) in 50-50 proportion.
5. Application of Zn SO4 at 25 kg ha-1 along with other soil deficient micronutrients for intensive cropping systems involving rice is recommended.
Water Management:
1. For transplanting, puddled field should be drained to retain a shallow depth of submergence (2 cm) at planting.
2. Water must be maintained to a depth of 5 cm for 3 to 4 days after transplanting to keep the planted seedlings straight for better stand establishment.
3. A shallow depth of 2 cm depth is adequate up to PI.
4. From PI to heading, maintain 5 cm land submergence.
5. For fertile heavy soils, mid-season drainage is recommended at late tillering for 2 to 3 days.
6. The field must be drained gradually 20 days after full flowering stage. This helps in achieving higher milling.
Weed Management:
1. Intensive puddling is very effective for weed management in the west system.
2. First 30 DAP is critical period for weed completion.
3. Two manual weedings, 20 and 40 DAP could be effective.
4. Herbicides like Oxadiargy and mixed chemicals like Pretlachlor + 2,4-DEE, Anilophos + Trichlopyr, Anilophos + Ethoxysulfuron, Almix + Anilophps and Cinmethylin + 2,4-DEE are found, in the recent past, performing better under transplanted conditions. Anilophos + Trichlopyr, Anilophos + Ethoxysulfuron appears to be effective in direct seeded rice.
5. Integrated weed management involving intensive puddling, land submergence and herbicides can eliminate manual weeding.
2. Dry System:
This system is confined mainly to rainfed ecosystems with no supplementary irrigation facilities. Field is usually prepared with animal drawn local implements with the receipt of summer or early monsoon rains. Seeding is either by broadcast or drilling in rows. All the cultural operations are carried out manually.
Tillage:
1. Open the land after harvest of the previous crop with mould board plough to prevent the land from getting hard on drying and to conserves moisture in subsoil. Premonsoon showers in April and May help to break the clods.
2. Whenever possible, give one or two summer ploughings to minimise weed growth.
3. Ensure deep tillage and fine tilth at the time of final land preparation for sowing.
4. Application of adequate amounts of compost or farmyard manure (5 t ha-1), deep ploughing and subsoiling across the slope conserve soil moisture and facilitates line sowing and deep seeding.
Varieties:
Varieties around 90 days duration group may be preferred to avoid terminal soil moisture stress. Tulasi, Aditya, Rasi, Anjali and Kanchan for Bihar; Birsa Dhan 101,105, 108 and 201, Birsa Vias Dhan 109 and 110 for Jharkhand; GR 2, 3, 6 and 8 for Gujarat; Annada, Rashmi and Rathe for MP; Tulasi, Prasanna, HMT Sona and Makarand for Maharashtra; Heera, Kalinga, Sneha, Nilagiri and Badami for Orissa; Narendradhan 18, 80, 97 and 118 and Pantdhan 16 for UP and Rasi, Kiron and Bhupen for WB are some of the recommended varieties for rainfed uplands in the country.
Stand Establishment:
1. Row seeding, preferably dibbling (hill sowing), adopting a spacing of 20 x 15 cm behind plough or seed drill.
2. Seeding time is first fortnight of June for alluvial soils and second fortnight of June for lateritics.
3. Seed rate around 60-80 kg ha-1.
4. Seed treatment with Chloropyriphos at 1 kg a.i 100 kg-1 seed controls termite effectively.
Fertilisr Management:
1. Use 60 N, 40 P2 O5 and 40 K2 O kg ha-1 for semi dwarf varieties. Entire recommended doses of P and K are to be given at sowing. Apply N in 3 splits (50% at 20 DAS; 25% at 45 DAS and 25 at PI).
2. For semi tall varieties, apply 40 N, 20 P2 O5 and 20 K2 O kg ha-1. Entire P and K to be given at sowing. Apply N in 3 splits (50% at 20 DAS, 25% at 45 DAS and 25 at PI).
3. Incubates FYM (2 t ha-1) with recommended dose of superphosphate (P2 O5) and apply the same in furrows at sowing.
Weed Management:
1. One summer ploughing with the first rain is necessary to kill weeds, especially Cyprus rotundus.
2. First 30 DAS is critical period for weed competition.
3. Use of finger weeders, wheel hoes, blade harrows and wheel-cum-finger weeders for controlling weed in between rows.
4. In laterite soils, running narrow plough between rows will be useful.
5. Combination of stale seed bed and preemergence application of Butachor at 1.5-2.0 kg a.i ha-1 0-6 days after sowing supplemented with one hand weeding at 40 days after sowing provides season long weed control.
3. Shallow Lowland (< 30 cm) or Favourable Situation:
Among the rainfed lowland rice systems, shallow depth of land submergence system is the next best rice system compared to irrigated rice (wet system) in which depth of land submergence can be regulated to the advantage of rice crop since irrigation water management is under the control of irrigators.
Tillage:
1. Open the land immediately after the harvest of the previous crop, preferably with a mould board plough to prevent the soil becoming hard on drying in the summer.
2. The premonsoon showers in April-May disintegrate the clods formed at post harvest ploughing and land preparation to sowing becomes quicker and easier.
3. One or two summer ploughings after premonsoon showers in April-May makes the land ready for early/timely sowing.
Varieties:
Ranjit and Bahadur for Assam; Rajshree and Vaidehi for Bihar; Mahamya and Shamla for Madhya Pradesh; Dharitri, Savitri, Jagannath, Moti, Padmini, Tapaswini, Chandrama, Swarna and Gayatri for Orissa; Jogen, Mahsuri, Neeraja, Pankaj, Swarna for West Bengal; Lal-lahari and Mahsuri for Uttar Pradesh are suitable for transplanted/direct seeded rice.
Nursery Management:
1. Adopt the seeding density in nursery using only 40 g seed m-2 to produce thick, robust and healthy seedlings.
2. Apply 100 N, 20 P2 O5 and 20 K2 O kg ha-1 to nursery for producing healthy seedlings. Correcting zinc deficiency and P in the nursery also is beneficial.
3. Seedling root dipping in Dursban (Chloropyriphos) solution (0.02%) before planting helps in controlling rice whorl maggot, stem borer etc. (in case of transplanted crop).
Stand Establishment:
1. In case of direct seeded crop, sowing must be completed by the 1st week of June. Hill sowing with a spacing of 20 x 15 cm with a seed rate of 80 kg ha-1.
2. In case of transplanted crop, early planting in the first fortnight of July adopting a spacing of 20 x 15 cm is ideal for high grain yield.
Fertiliser Management:
1. A balanced fertilisation dose of 60 N, 40 P2 O5 and 40 K2O kg ha-1 is required.
2. Split application of N as under wet system.
3. Around 50:50 organic-inorganic combination is ideal for sustained productivity.
4. Modified urea materials like rock phosphate, coated or nimin coated urea and urea super granules help in improving N use efficiency.
5. Apply 20-25 kg Zn SO4 ha-1 to the main field, if the soil is deficient in zinc.
Weed Management:
1. First 30 DAS is critical for weed competition.
2. Beushening or running cono-weeder in between rows (for direct seeded rice) around 35- 40 DAS helps in weed control and improving yields.
3. Apply Butachlor or Thibencarb at 2.0 kg a.i ha-1 at 0-6 days after sowing to control weeds in case of direct seeded crop (MP and Orissa).
4. Unfavourable Lowlands (30-100 Cm):
Tillage:
1. Open the land immediately after the harvest of the previous crop, preferably with a mould board plough to prevent the soil becoming hard on drying in the summer.
2. One or two summer ploughings after premonsoon showers in April-May makes the land ready for early/timely sowing.
Varieties:
Recommended varieties are CR 260-77, Sonamani, Kalashree, Utkalprabha, CR 1014, Tulasi, Rajashree, Manoharsali, Panidhan, Lunishrce, Sudha, Janaki, Vaidehi and Gautam.
Stand Establishment:
1. Sowing during second fortnight of May, using 400 seeds m-2 (100 kg ha-1).
2. Planting with clonal tillers removed from an established direct seeded crop/aged seedlings in case of crop failures.
3. Mixed cropping of long duration varieties and early varieties in alternate rows 15 cm apart help in increasing total yield up to 19 per cent and acts as an insurance against crop failures.
Fertiliser Management:
1. Recommended fertiliser schedule is 40 N, 20 P2 O5 and 20 K2 O kg ha-1
2. Furrow placement of all the NPK with FYM (5 t ha-1) at sowing improves yield.
5. Deep Water Situation (>100 cm):
Varieties:
Jaladhi-1, Jaladhi-2, Jalmagna, Jalpriya, Barh awarodhi, Sudha, Janaki, Vaidehi.
Tillage:
1. Open the land immediately after the harvest of the previous crop, preferably with a mould board plough to prevent the soil becoming hard on drying in the summer.
2. The premonsoon showers in April-May disintegrate the clods formed at post harvest ploughing and land preparation to sowing becomes quicker and easier.
Stand Establishment:
Direct seeding during second fortnight of May in Orissa but in March itself in other parts like Bihar and Assam, at 20 cm row spacing with a seed rate of 80-100 kg ha-1 (300-400 seeds m-2).
Fertiliser Management:
Application of 40 N, 20 P2 O5 and 20 K2 O kg ha-1 in furrows at seeding.
6. System of Rice Intensification (SRI):
Nursery Management:
1. Raised nursery bed, similar to regular crops.
2. Seed rate 5 kg ha-1.
3. Nursery area 2.5 cents ha-1 of main field.
4. Apply a layer of fine manure on seedbed.
5. Distribute pre-sprouted seed uniformly.
6. Cover the seed with another layer of fine manure.
7. Mulching seedbed with paddy straw.
8. Regular watering to keep the seedbed moist.
Main Field Preparation:
1. Similar to that of lowland rice.
2. Perfect land leveling.
3. Drainage channels at 2 to 3 m interval.
4. Draw lines both ways (25 x 25 or 30 x 30 cm) with marker.
Manuring:
1. Incorporate around 5 t ha-1 of compost or FYM during main field preparation for better soil health.
2. Depending on the necessity, top dress with chemical fertilisers.
Transplanting:
1. Transplant 8 to 12 days old seedlings with seed intact, having 2 or 4 leaves.
2. Banana leaf sheaths may be used for lifting the seedlings from nursery bed.
3. Carefully lift the seedlings with seed, soil and roots using banana leaf sheath by inserting it below the root system and carry to the main field.
4. Place single seedling with seed, soil and roots at 25 x 25 or 30 x 30 cm intersecting points marked with the marker.
5. Place the seedling without plunging too deep into the soil.
Water Management:
1. Regular water application to keep soil moist but not saturated.
2. Intermittent wetting and drying for adequate aeration during vegetative phase.
3. Relatively frequent watering after vegetative phase.
4. No water stagnation at any stage.
Weed Management:
1. Severe weed infestation due to moist soil than land submergence.
2. Use simple rotary weeder between crop rows in both the directions starting from 10 days after planting.
3. About four rotary weedings at 10 to 15 days interval could be adequate till panicle initiation.
4. If necessary, one or two hand weedings may be necessary to remove weeds closer to rice plants.
7. Aerobic Rice System:
This system is similar to other crops such as irrigated wheat, maize, groundnut, cotton etc.
Tillage:
Field preparation is similar to that for any other irrigated crop.
Varieties:
1. There is urgent need for developing high yielding cultivars for this system.
2. Testing the performance of some of the improved varieties and hybrids like Anjali, IR 55419-04, Proagro 6111 and Pusa RH 10 etc. under aerobic system at WTC, IARI raveled scope for about 50 per cent saving in irrigation water with grain yield around 3 t ha-1.
Crop Culture:
1. Recommended seed rates are 60 to 80 kg ha-1 for manual dropping of seed in plough furrows and 40 to 50 kg ha-1 for seed drill seeding.
2. Gap filling and thinning should be completed within a month after seeding.
3. Recommended fertiliser schedule is 150 N (50 at seeding, 50 at tillering and 50 at anthesis), 60 P2O5 (basal) and 40 K2O (basal) kg ha-1.
4. Availability of other nutrients such as zinc and manganese may also limit rice yield under aerobic conditions.
Water Management:
1. In the absence of rain, irrigation may be given at 20 to 40 kPa after seed germination.
2. From booting to completion of anthesis, irrigations must be given to maintain soil moisture level between soil saturation and FC.
Iron Deficiency Management:
Iron deficiency is common in aerobic rice system.
1. Soil application of Fe SO4 at 30 kg ha-1 is recommended at seeding if the soil is deficient in iron (extractable Fe < 4.5 mg kg-1).
2. If iron deficiency is observed in standing crop, foliar spray of 2 per cent Fe SO4 or Fe chelates is recommended at two weeks interval starting from tillering.
Weed Management:
1. Since rice and weed seeds germinate simultaneously in aerobic rice system, weed infestation is a potential threat to successful rice production with this system.
2. An effective weed management strategy, at the cost of huge expenditure, is an essential component of aerobic rice system.
3. Use of herbicides is a must for timely weed control. Herbicides like Anilophos + Trichlopyr and Anilophos + Ethoxysulfuron appears to be effective.
4. Integrated weed management involving herbicides and manual hand weeding is a must for optimum grain yield of rice.
Pest Management:
1. Rice root-knot nematode often becomes yield reducing factor under successive aerobic rice cultivation.
2. Applications of Carbofuran (3 kg a.i ha-1), three weeks after gennination, in saturated soil condition can minimise its infection.
3. Ploughing the land and exposing to summer heat is one of the effective methods of its management.
Grain Yield:
1. Improved cultivars ‘Han Dao’ developed in China and ‘Apo’ at IRRI, especially for aerobic system, are yielding around 6 t ha-1 relative to their yield around 7 t ha-1 under lowland systems, with 50 to 60 per cent saving in irrigation water.
2. As of now, performance of the present day improved cultivars ideal for rainfed uplands and lowlands and irrigated lowlands is not encouraging aerobic rice system in India.
3. Development of appropriate genotypes and crop production technology to overcome problems like weed and nematode management, iron and other nutritional disorders and change in grain quality under aerobic system are the need of the hour.