The System of Rice Intensification (SRI) forSuper High Yield of Rice in Sichuan Basin

Zheng Jiaguo, Jiang Xinlu, Lu Xianjun, Tang Yonglu(Crop Research Institute, Sichuan Academy of Agricultural Sciences, China )

Leaf Area Index and dry-matter accumulation are much higher with SRI plants than for controls (CK)

Stems are strong and root system is well developed

Item Rice Stage Stem SheathGreen leaves

Withered leaves

Panicles Biomass

SRI

Full heading

6,396 6,555 7168.6 315.5 2,362 24,902

Mature 4,109 3,266 3390 2,667.3 13,592 25,407

CK

Full heading

3,775 5,595 3880.9 254.2 1,205 14,710

Mature 2,475 3,065 1661.2 1,639.6 7,936 15,833

SRI over CK(%)

Full heading

69.4 17.2 84.7 24.1 96.0 59.1

Mature 66.0 6.6 104.1 62. 7 71.3 60.5

Comparison of Dry Matter Accumulation

Fig. 1 Dynamic change of Leaf Area Index (LAI)

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06-J ul 16-J ul 26-J ul 05-Aug 15-Aug 25-Aug

Date

L A

I

SRI

CK

Differences in Leaf Blade (cm)

Item

3rd leaf 2nd leaf Flag leaf Average

Length Width Length Width Length Width Length Width

SRI 64.25 1.57 71.32 1.87 57.67 2.17 64.41 1.87

CK 56.07 1.43 62.03 1.57 48.67 2.01 55.56 1.67

SRI Incr. 8.18 0.14 9.29 0.30 9.00 0.16 8.86 0.20

% 14.59 9.79 14.97 19.11 18.49 7.96 15.95 11.98

Internode, Panicle and Culm Length (cm)

  6th 5th 4th 3rd 2nd 1st

Panicle

Length

Culm length

SRI 2.63 7.5711.7

314.4

722.4

745.4 25.64 137.79

CK 1.5 4.87 8.0712.0

321.0

741.7

725.17 118.98

%75.3

355.4

445.3

520.2

86.64 8.69 1.86 15.81

The improvement of SRI in Sichuan

40cm

40cm

Square planting with single seedling

Original

SRI

Improved

SRI

45cm

40cm

7cm

Oblong planting with triangle pattern

7

8

9

10

11

12

13

14

CK SRI S+3 S+T O+T

Transplanting pattern

Yie

ld(T

/ha)

Comparison of Transplanting Patterns

S+3= Square with 3 seedlings; S+T=Square with triangle; O+T=Oblong with triangle

Transplanting PatternYield(T/ha)

Comparing to CK

+ T/ha + %

Traditional (CK) 8.65 -- --

Standard SRI 10.42 1.77 20.4

Oblong + triangle SRI 13.39 4.74 54.8

Comparison between Triangle SRI and Standard SRI (SAAS, 2002)

Variety CXY 157

CXY 179

ⅡY 7

Spacing(㎝ )

40 40 40

Seedlings/hill

1 1 1

Hills/㎡ 6.25 6.25 6.25

Max. Tillers/hill

321.3 336.7 324

Panicles/㎡

177.9 172.8 172

Yield (t/ha) 10.03 10.47 9.62

Plant type is important. If the function leaves are too long, at the late growth stage their photosynthesis will decrease

Varieties Give Different Responses to SRI

Conclusions on SRI To Date:

• More grain is produced by these methods• Fewer insect and disease problems• Reduction in the amount of seeds needed • Water saving is achieved• But increase in time needed for irrigation • Land leveling has to be done more carefully• More weeding is needed• Organic fertilizer supply can be a constraint• Harder to transplant and manage small plants

Less input higher output , but more manual work

General speaking, the yield for farmers’ practice is about 8.5 t/ha in Sichuan.

• When SRI is introduced, the yield is increased about 20%.

• With improved SRI, the increase in yield is about 50%.

Preliminary Evaluation: SRI Is a Promising Way to Increase Yield

Factors Limiting Adoption

• It is harder to transplant the young seedlings at 2-leaf age in multiple cropping systems.

• Organic fertilizer is in short supply.

• Management practices such as hand weeding and keeping the soil moist are thought to be complex and laborious.

Mushroom Productionwith SRI

Tray nursery to raise young seedlings

Seedlings planted on mushroom beds