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DIRECT SEEDING OF RICE (WET AND DRY)

DIRECT SEEDING OF RICE (WET AND DRY). Next. End. abstract. Direct seeded rice plays greater role in satisfying the rice grain requirement of the people of the world. Under direct seeding, the rice seeds are directly sown to the well prepared main field (either in dry or wet condition).

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DIRECT SEEDING OF RICE (WET AND DRY)

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  1. DIRECT SEEDING OF RICE (WET AND DRY) Next End

  2. abstract • Direct seeded rice plays greater role in satisfying the rice grain requirement of the people of the world. • Under direct seeding, the rice seeds are directly sown to the well prepared main field (either in dry or wet condition). • In dry rice cultivation, seeds are treated with 1% KCl and sown at 15-20 cm distance using seed drills at 5cm depth. • The seeds are soaked in water and kept in dark for sprouting before sowing in wet rice cultivation. • The sprouted seeds are sown in well puddled and leveled fields using drum seeders. • Both the methods are having their own merits and demerits. Previous Next End

  3. INTRODUCTION • Rice growing conditions in different regions largely influence the system of cultivation. • The main factors are location of land, intensity and distribution of rainfall, type of soil, class of rice, season, irrigation resources and availability of labour. • Rice cultivation is made in two types • One is seeds are sown either in dry soils or in puddled lands, popularly called as ‘direct seeded rice’ . • Another is ‘transplanted rice’ wherein, seedlings are raised in nursery and transplanted in the puddled fields. (Cont).. Previous Next End

  4. Direct seeded rice • Direct seeded rice is of two kinds. 1. Dry rice cultivation 2. Wet rice cultivation. • All the field operations are carried out in dry field (non saturated condition) for dry rice cultivation, whereas, wet rice cultivation is practiced in puddled field situation Previous Next End

  5. Learning objectives • To study the detailed cultivation methods of both dry and wet (direct seeded) rice with their relative merits and demerits. MAIN BODY • DRY RICE CULTIVATION • WET RICE CULTIVATION Previous Next End

  6. DRY RICE CULTIVATION • Dry rice cultivation is followed in uplands where there is less possibility for water stagnation. • Uplands are characterized by aerobic soil in which attempt is made to impound water. • Upland rice is grown on both leveled and sloppy fields those are not bunded and are prepared well for dry seeding. • The rice crop solely depends upon rainfall for its water requirement. • This system of cultivation is followed in many parts of the world, however, mainly confined to tracts that don’t have adequate irrigation facilities. Previous Next End

  7. The land is ploughed sufficiently during summer to get the good tilth and sowing of rice is usually done in immediately after onset of monsoon. • Upland rice is called differently in many parts of India as Aus in West Bengal, Aus or Ahu in Assam, Beali in Orissa, Bhadai or Kuari in Uttar Pradesh (Chatterjee and Maiti, 1988). • In areas generally having medium rainfed (shallow low-land) and low-lands, semi dry system of cultivation is followed. • Under this system of cultivation, the field is prepared and dry rice sowing is made. • The crop is treated as a dry crop for about two months (or until receiving monsoon rains) after seeding and is then, treated as wet crop when monsoon gets intense. Previous Next End

  8. Important practices of dry and semi-dry system of cultivation are discussed below. Sowing • Seeds are generally hardened with 1% KCl solution to induce drought tolerance, treated with bio-fertilizers and drill sowing is made. • Sowing of the dry and semi-dry crop should be done in right time for getting maximum yield. • Yield of the late sown crop has been found to be invariably low. • Results of the experiments conducted in various states of India revealed that earlier the sowing (after onset of monsoon), better and higher was the yield. (Cont).. Previous Next End

  9. Method of sowing • Three methods are commonly followed in sowing dry and semi-dry crop. • These are broadcasting, drilling or sowing in furrows behind plough and dibbling. Drill sowing of rice (Source: http://agropedia.iitk.ac.in/?q=content/method-planting-rice) Previous Next End

  10. Seed rate • Seed rate depends upon the duration and test weight of variety. • Soil tilth, moisture content and system of cultivation also determine the seed rate requirement. • Optimum seed rate should be adopted for the direct seeded crop so that crop stand is neither too thick nor too thin. • In general, a seed rate of 30-50 kg ha-1 is required for drilling, while 60-100 kg ha-1 is required for broadcasting. Spacing • Spacing to be adapted depends mainly upon the fertility of the soil and duration of the variety. • Row spacing of 15-20 cm is optimum for upland rice. • For low-land situation, plant population of direct seeded crop should be similar to that of transplanted one. Previous Next End

  11. depth • To obtain uniform and better germination, it is necessary that the seeds should be placed at optimum depth. • A study on the germination of the seeds sown at varying depths revealed that the seeds sown at 5 cm depth took about 4 to 6 days for their plumules emergence on the surface of the soil • while the seeds lying exposed on the surface as well as those below 5 cm depth required 6 to 10 days for emergence. • The seeds lying at a depth below 10 cm from the soil surface germinated but their plumules didn’t come out of the soil and died. • Therefore, seeding depth of rice should not be more than 5 cm and preferably it must be 3-5 cm. Previous Next End

  12. AFTER CULTIVATION • Application of Pendimethalin @ 1 kg ha-1 on 5 days after sowing (DAS) or Pretilachlor + safener (Sofit) @ 0.45 kg ha-1 followed by one hand weeding after 30-35 DAS can reduce the weed dominance. • Thinning and gap filling will be made after 2-3 weeks. Spraying of Kaoline 3% or KCl 1% in moisture stress condition can withstand the rice crop. • Judicious fertilizer management is necessary for better crop. Previous Next End

  13. 2. Wet rice cultivation • In wet system of cultivation, the rice crop is grown under wet (season) condition right from sowing to harvest. • In this system, the field is repeated ploughed with 5-7 cm standing water (puddling). • Rice fields with sandy to sandy loamy soils are ploughed in summer and again ploughed once or twice after letting in water to get the requisite puddled condition. • Heavy soils of clay nature are not generally opened in summer. The wet cultivation is two kinds. • Transplanting • Direct seeding sprouted seeds in puddled soil. Here, the direct seeding under puddled condition is discussed. Previous Next End

  14. Direct seeding of sprouted seeds in puddled soil • This method is adopted in areas where there is shortage of labourers or labour wages are very high and also where mechanical seeders are available. • The field is prepared and puddled as like in transplanted rice. • Puddling offers a number of advantages. • All weeds are killed and buried in to the soil (otherwise compete with rice plant for nutrients and water). • Infiltration rate of water is reduced and water retaining capacity of soil increases. • Germinate the seeds easily in soft mud. • Plant population becomes more assured • Availability or Fe and P increases and N is conserved better. Click The Picture To View The Information End Previous Next

  15. After thorough puddling, the field is leveled, excess water is drained out and then pre-germinated seeds are sown • Excess water at seedling time leads to poor germination due to seed mortality because of paucity of oxygen. • Where the depth of water is more, the plumules elongate more than the radicles and the seedlings float on the impounded water and don’t anchor properly. • If the water is muddy, soil particles should be allowed to settle before seeding. • This prevents soil from covering the seeds. • Oxygen supply to the seed decreases in muddy water due to covering of seed by settling mud. • Drum seeders are generally practiced in puddled condition and 20cm row spacing is maintained. • Pre-emergence application of Pretilachlor @ 0-75 kg ha-1 on 8 DAS or Pretilachlor + safener (Sofit) @ 0.45 kg ha-1 followed by one hand weeding after 30-35 DAS are recommended practices for weed management. • During the first week, thin film of water is maintained, whereas, afterwards, 2.5cm to 5.0cm water level is recommended. Previous Next End

  16. The main disadvantages of this system are seeds are exposed to rat and bird attack and seeds are washed away during heavy rains resulting in poor stand of seedling. • To overcome these disadvantages, pre-germinated seeds are sown in the puddled land with 5 cm standing water. • This protects the seeds from bird attack and helps in controlling grassy weeds due to standing water but emergence and establishment of seedlings are low. • There is possibility of reduction in plant stand due to floating of seeds, in case the water depth is beyond 10 cm high. • A field study for standardization of seed rate of rice varieties for broadcasting of sprouted seeds under puddled condition showed that there was a significant increase in yield up to 100 kg ha-1 seed rate. • Hence, 80-100 kg ha-1 of seeds is optimum for wet-seeded rice cultivation. Previous Next End

  17. Sowing dry seeds vs. sprouted seeds in puddled field • It is the usual practice to sow un-germinated seeds in dry soil and sprouted seeds in puddled soil. • Relative merits of sowing dry seeds vs. germinated seeds in puddled soil revealed that sowing of dry seeds in puddled soil gave comparable yield with that of pre-germinated seeds. Previous Next End

  18. summary • Rice cultivation is made in two types. One is ‘direct seeded rice’ and another is ‘transplanted rice’. • Direct seeded rice is of two kinds. 1. Dry rice cultivation and 2. Wet rice cultivation. • In dry rice cultivation, soil is prepared as like upland crops, seeds are sown at a row spacing of 15-20 cm at 3-5 cm depth immediately after onset of monsoon. • In wet system of cultivation, the rice crop is grown in puddled fields. The field is leveled and sprouted seeds (80-100 kg ha-1) are sown in puddled soil. • Sowing of dry seeds in puddled soil gave comparable yield with that of pre-germinated seeds. Previous Next End

  19. Assessment • KCl 1% solution is used as seed hardening chemical in dry rice cultivation (True/False) • Normal row spacing adopted for dry rice sowing is 25-30 cm (True/False) • Optimum depth of sowing for dry rice is 3-5 cm (True/False) • Drum seeders are generally used for sowing in puddled soils at 15-20 cm spacing (True/False) • Generally, sprouted seeds are used in wet rice cultivation (True/False) Previous Next End

  20. References • Bell, M.A., G.F. Patena and D.C. Mendoza. 1998. Drill sowing of pre-germinated rice seeds: effect of rainfall on plant stand. IRRN, 23(2):38. • Chatterje, B.N. and S. Maiti. 1988. Principles and Practices of Rice Growing. Oxford and IBH Publishing Co. Pvt. Ltd., New Delhi. • CPG, 2005. Crop production Guide. Tamil Nadu Agricultural University, Coimbatore and Commissioner of Agriculture, Chennai, India. • Mohapatra, A.K. 1992. Response of rainfed lowland rice (Oryza sativa) to timing of beushaning and nitrogen management. Indian Journal of Agronomy. 37: 159-160. • Rajendra Prasad, 1999. A text book of Rice Agronomy. Jain Brothers, New Delhi. • Rao, M.V. 1985. Cultural practices for rice. Rice Research in India. Indian Council of Agricultural Research, New Delhi. Previous

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