Overview of System of Rice Intensification in Cambodia Chou Cheythyrith National FAO-IPM Project Coordinator, Ministry of Agriculture Forestry and Fisheries, in collaboration with Regional FAO Vegetable IPM Program

Background of SRI SRI is a set of improved practices or methods in plant, water, soil and nutrient management being used to bring out rice natural growth potential SRI was introduced in 1999, with field tests by farmers beginning in 2000, supported by CEDAC MAFF supports SRI through an SRI Secretariat that implements activities in 24 provinces and municipalities 32 NGOs have implemented SRI with activities educating and assisting farmers Presently, more than 60,000 households are practicing SRI on the area about 16,385 ha IPM Program conducts SRI Participatory Action Research and educates farmers to grow healthy crops

Principles and practices of SRI According to their natural potential, rice plants have ability for: More profuse tillering tillers per plant, with some having many more tillers Larger and deeper root systems Larger panicles Higher quality grain, with fewer unfilled and fewer broken grains, and often higher grain weight Traditional/conventional practices inhibit crop growth and do not allow rice plants to achieve their full potential, while SRI methods create a conducive environment for rice plants to grow

Tillering potential of rice plant

Difference between traditional and SRI practices Traditional Rice field is continuously flooded with high level of water during the vegetative stage Seedlings are raised with much water, and seedling density is high Transplanting with too many seedlings per clump, mixture of weak and thick seedlings SRI Only minimal water, preferably keeping the soil only moist and in dry/wet condition Seedlings are raised in beds like vegetable bed, and the seed density is very low Young seedlings are used, preferably less than 15 days old (at 2-3 leaf stage)

Difference between traditional and SRI Traditional Seedling age is too old, generally more than one month Seedling is uprooted with damage to root and stem, and is kept for one to two days before transplanting Seedlings are transplanted with close spacing and no equal spacing SRI Only 1 to 2 seedlings, but preferably one seedling per clump, only vigorous seedlings Young seedling is uprooted and transplanted with care, transplanted immediately after uprooting Wide spacing and square pattern, or at least line transplanting

Difference between traditional and SRI practices Traditional Weeding is not early enough, not frequent and regular Limited Use of farmyard manure, and dependence on use of chemical fertilizers SRI Early weeding and frequent weeding to improve soil aeration Application of compost as much as possible

For SRI, the best result or the optimal yield is achieved only through the proper combination of the improved practices that create a synergy effect. The more good practices that farmers can apply, the more yield they will get. To begin, if farmers just select only strong seedlings for transplanting, reduce the number of seedlings per clump, and do shallow transplanting, their yield can be increased by more than 30 % (at no extra cost !).

Highlights of the results in the wet season 2006:  Average SRI yield was 4.7 tons per ha, while the average yield of conventional practice is 1.92 tons per ha  Around 20 % of farmers were able to harvest more than 4 tons per ha  All SRI farmers were able to reduce the amount of rice seeds and fertilizer that they used be significant amount, thus reducing cost

SRI field

Better root and shoot growth with SRI

No. of farmers applying SRI in Cambodia

Progress of SRI area in Cambodia (ha)

Supported by Regional FAO Vegetable IPM Program

SRI Introduction Findings from Cambodia Implications

PAR-SRI Research, Cambodia  Effect of different water regimes and planting densities on rice yield. Treatment: Three water regimes  Alternate wet and dry (AWD)  Flooded field (FF), and  Just moist (JM) Three planting densities  Single seedling with 15 x15 cm  Single seedling with 30 x 30 cm  Six seedlings with 15 x 15 cm

Result Root growth Criteria for healthy root growth:  More root volume  More number of white and fine roots  More number of laterals  More number of crown roots Trend under different water regimes and planting densities:  Single seedlings with wider spacing had better root growth  More number of white and fine roots were seen under just moist (JM) condition.

Effect on yield-con tributing parameters Grains/panicle 1000-grain weight Tillers/m2 Grain yield (t/ha)

Implications  Effect of root length density on rice yield should be evaluated with different soil types (sandy, clay, loam)  Varietal evaluation is needed under different soil types  Location-specific research is needed for optimizing G x E (variety-environmental) interaction for better productivity using participatory action research  Farmers should be seen as active research partners in PAR trials

Concluding remarks  SRI movement is growing very fast in Cambodia, with increasing number of farmers involved and support/implementing organizations/projects  There is need to reinforce this momentum by providing assistance to farmers in further developing and disseminating SRI to ensure that the maximal number of farmers can have sustainable benefit from SRI

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