Modified SRI and super-high yield of hybrid rice in Sichuan Basin

Jia-guo Zheng, Xin-lu Jiang, and Zhong-zhi Chi Sichuan Academy of Agricultural Sciences

Chengdu, China

30cm

15cm

Farmer practice – typical spacing

40cm

40cm

Original SRI as used in Sichuan

Limiting factors for adoption

• The number of foundation plants used with SRI originally in Sichuan, at 40x40 cm, did not appear suitable in ecosystem with the low solar radiation of this region.

• Single plants in a square pattern with wide spacing do not produce sufficient panicles. Consequently, yield potential is limited. Farmers want to maximize their number of panicles/m2, not panicles/hill. (Note: SRI recommendation is usually 25x25 cm spacing, not 40x40 cm .)

• The oblong and triangular planting method introduced in Sichuan appears to be a valuable adaptation of SRI, as it increases plant density by 50% while maintaining good exposure of individual plants to the sun and air.

40cm

35cm

7cm

Modified SRI: hills in oblong (rectangle) pattern with plants in triangular spacing

Using tray nursery to raise seedlings

• The seedling nursery is managed under upland conditions, with plastic tray.

• Seedlings are removed carefully from the nursery and are transported and placed gently into the paddy field within 15-30 minutes.

• This avoids a long recovery time, and leaf age can be extended to 3.5-4.5.

Making shallow furrows before transplanting in the zero-till fields.

• This is appropriate for the alternate wetting and drying (AWD) method, as an effective and easy method for SRI water management.

• Shallow furrows help to implement AWD,

maintaining aerated soil surfaces while some water in the furrows moistens the root zone.

Making shallow furrows

It is hard to transplant young seedlings at 2-leaf age within a multiple cropping system.

• Traditionally older-aged seedlings (about 7-leaf ) are transplanted into fields in rice-wheat (RW) cropping system.

• If very young rice seedlings are used, the sowing date has to be postponed, which leads to some unexpected results, such as late maturity, less yield, and difficulties in field management.

Mushroom production

Resource using cycle

Year 2004 2005 2006 2007 2008 2009

SRI area (ha) 1,120 7,290 57,500 116,667 204,000 285,867

SRI yield (t/ha) 9.10 9.44 8.82* 8.99 9.41 9.51

Conv. yield (t/ha)

NA NA NA 7.5 7.71 7.68

SRI increment (t/ha)*

NA NA NA 1.49 1.70 1.83

SRI % increase in yield*

19.85 22.03 23.83

SRI additional net income (RMB/ha)*

1,574 1,956 2150

SRI extension in Sichuan

Dr. Lin Xianqing

E-mail ： xqlin2003@163.com

China National Rice Research Institute

Workshop on SRI rice technologyWorkshop on SRI rice technology

Evaluation of Key Factors of SRI Method

Operations of SRI

A. Precision seeding with seedlings in trays

B. Density control in transplanting

Transplanting density: 13.5-19.5 x 104 hill/ha

C. Standard of field water control is by shallow wetting-drying (SWD)

Three Shallows – during transplanting, when

spraying with insecticide, and during booting-flowering stage

Three Wets – during tillering, panicle initiation, and

milk grain-maturing stage

One Dry – for tiller control

Shallow Wetting-Drying (SWD) =

Shallow-water puddling

Wet tillage

Shallow-water during transplanting

Dry for tiller controlWet for tillering

Wet for maturing grain

Shallow-water for booting to flowering

Wet for milk grain

D. Maintaining N and increasing K levels

Need to increase organic fertilizer

E. Integrated Pest Management (IPM)

Demonstration of SRI in Bu Tou Village, Tien Tai Township, Zhejiang

Technical Guidance

Application area of SRI in Zhejiang 2005-09

688,000 ha

Calculated increase in production from SRI use

862,000 tons

(+1.253 t/ha)

THANKS 谢 谢