1. Rice Growing Ecosystems

2. Classification of Rice Growing Ecosystems Source of water supply Rainfed Irrigated Land and Water management practices Soil condition Technological level

3. World’s Rice Land Classification Lowland rice Irrigated lowland rice Rainfed lowland rice Upland rice Deepwater rice Floating rice

4. World’s Rice Land Classification……… Irrigated lowland rice have sufficient water available during the entire growing season, with controlled shallow water depth between 5 to 10 cm Rainfed lowland rice mainly dependent on the duration of rainfall and hence with an uncontrolled shallow water depth, ranging from 1 to 50 cm

5. World’s Rice Land Classification….... Upland rice bunded or unbunded rained fields with no surface or rhizosphere water accumulation Deepwater rice unbunded fields with maximum sustained water depth from 0.5 m to 1m Floating rice maximum water depth ranges between 1m to 6m for more than half of the growth duration

6. Rice Growing Ecosystem in Sri Lanka Rice land under major irrigation schemes-41% Rice land under minor irrigation schemes-25% Rainfed rice land-34% Upland rice

7. Irrigated Lowland Rice System 45% of world’s total rice land 32% of South and Southeast Asian land 50% of production of South and Southeast Asian rice Method of establishment - Transplanting - Direct seeding on puddled soil (broadcasting –pre germinated) - Drill seeding into dry land soil - Broadcast seeding into water Use new improved and hybrid, fertilizer and agro chemicals Use modern technology and machinery Early maturing rice ( 3 – 4 months )

8. Irrigated Lowland Rice System……. Sri Lanka : 66% Low Country Dry Zone Ampara Anuradhapura Low Country Intermediate Zone - Kurunegala Yield : 5 t/ha

9. Rainfed Lowland Rice System 30% of world’s total rice land Majority of tropical Asia Enough water has to accumulate in the field before ploughing Method of establishment - Transplanting - Direct seeding on puddled soil(broadcasting – pregerminated) - Direct seeding on dry soil

10. Rainfed Lowland Rice System…….. Use new improved and hybrid, fertilizer and agro chemicals, modern technology and machinery Early maturing rice ( 3 – 4 months )

11. Rainfed Lowland Rice System…….. Sri Lanka- 34% -Low Country Wet Zone – Gampaha, Kaluthara -Low Country Intermediate Zone - Kurunegala -Mid Country Wet Zone – Kandy -Low Country Dry Zone (Maha) – Anuradhapura Yield : 3 t/ha Vegetable based system at dry zone Low yield at wet zone – low light intensity mono cropping system

12. Upland Rice System Mostly by small subsistence farmers in the poorest regions of the world 10% of world’s total rice land Asia – India, Bangladesh, Philippines, Thailand Sri Lanka- Shifting cultivation of Dry Zone (Chena) - Jaffna District Yield - 1 t/ha Use traditional varieties – drought tolerant

13. Upland Rice System……… Less land preparation Dry seed broadcasting No fertilizer application Problems – rainfall distribution change in nutrient in soil weed composition

14. Deepwater Rice System Standing water for a certain period of time is more than 50 cm Maximum water depth : 51-100 cm Cultivate in Stagnant water areas, Tidal swamp areas Thailand, India, Bangladesh, West Africa, Latin America Dry seeding or Transplanting Seed broadcast on dry soil Little fertilizer or pesticide application Flooding at 50- 60 days after seeding

15. Deepwater Rice System…….. Use long day maturing varieties (150 days- 240 days ) Submergence tolerance Ability to elongate if the water level increase Lodging tolerance Good seedling vigor

16. Floating Rice System Standing water 1m to 6m for more than half of the growth duration Maximum water depth : 1- 6 m Cultivate in floodplain areas Thailand, India, Bangladesh, Northern Nigeria Ungerminated seed broadcast on dry soil Little fertilizer or pesticide application Flooding at 4-20 weeks after seeding Use long day maturing varieties (3 – 10 months ) Yield : 0.4 – 1.0 t/ha

17. Floating Rice System……

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