This document discusses rice cultivation techniques for cold regions like Heilongjiang Province in China. It outlines the natural resources and climate of the region, which presents challenges for rice growth. It then details several ways farmers can address issues like chilling damage, lodging, and yield through practices such as selecting high-yielding varieties, optimizing seedling growth, transplant density, fertilizer application, irrigation, and timely harvesting. The goal is to produce high-quality, high-yielding rice even in cold conditions through careful agronomic management.

1. Super high- yielding rice cultivation techniques in cold region: Heilongjiong Province Jin Zhengxun Northeast Agricultural University Haerbin

2. Natural Resources in Heilongjiang Province Latitude :43°25′~ 53°33′ Area :45.4만 Km2 Elevation: 300~1780m Accumulated T:1800~2800℃ Annual mean temperature : 6 ~ 4℃ Average daily sunshine hours: 2400~2800 h Rainfall: 250~700mm，60% Frost-free period :100~140 d

3. The average temperature change in Heilongjiang Province

4. Comparison of day and night temperature difference

5. Rice cropping area in Heilongjiang Province

6. Change of rice yield in Heilongjiang Province

7. Cultivation problems in Heilongjiang Province 1. Chilling damage and blast of rice 2. Must pay special attention to the pre-transplant growth of plants 3. Transplant ultra-sparsely Lodging

8. Way To Solve Problems 1. Control pre-tillering number 2. Promote early heading 3. Increase maturity

9. 1. Select high-yielding varieties

12. 2. More tillers per plant in seedling bed

13. Seedling facility

14. Seedling transplanting method of two stages First stage: Sowing date: March 15 Sowing rate:100 g/tray Second stage: Transplanting date: April 15 Planting specification :2cm×2cm, 1 plant per hill

15. Large seedling trays（352 holes）

16. Mechanical sowing in straw trays

17. Mechanical sowing by hand

18. How to prevent leggy seedlings?

19. 3. Transplant seedlings with soil blocks

20. To turn seedlings green early

21. To facilitate planting by machine

23. 4. Appropriatetransplanting density

24. Relationship between plant density and yield components Low input :(N-P2O5-K2O) 6-3-3Kg/10a, High input:(N-P2O5-K2O) 12-6-6Kg/10a，Variety：Dongnong V4

25. Planting Specifications: 36 cm×16 cm, 2-3 plants per hill

26. 5. Maintain reasonable N rate and increase potash application rate Annual N application date（M、D ） N:P2O5:K2O = 1 : 0.5 : 0.8-1

27. Top-dressing principle of super-high yielding rice 1. Tillering fertilizer: top dressing after turning green,10% relaying fertilizer 10 d after first tillering fertilizer; 2. Top dressingat panicle initiation by diagnosis

29. When panicle length is 2cm, the stage is 15 d before heading;

31. 6.Irrigation method

32. Maintain moisture soil at 30 d after heading

33. 7. Harvest in timely way

34. Daily changes of grain weight

35. Daily changes of milled rice percent

36. Daily changes of taste-meter value of rice

37. Suitable rice harvesting time for good quality of rice Production quality and yield assurance – aiming for: Processing quality Eating quality Accumulated temperature after heading

38. Harvest date and grain maturity

39. Thank you ！