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Three Reductions, Three Gains (3R3G) Technology in South Vietnam:
Searching for Evidence of Economic Impact
Zenaida M. Huelgas, Deborah Templeton, and Pamela Castanar
Social Sciences Division
International Rice Research Institute
DAPO Box 7777, Metro Manila, Philippines
Contributed paper at the 52nd Annual Conference of the Australian Agricultural Resource
Economics Society held at Rydges Lakeside, Canberra ACT, Australia, 5-8 February 2008.
Three Reductions, Three Gains (3R3G) Technology in South Vietnam:
Searching for Evidence of Economic Impact1
Zenaida M. Huelgas, Deborah Templeton, and Pamela Castanar2
Abstract: The aim of the “Three Reductions, Three Gains” (3R3G) project is to reduce
production costs, improve farmers’ health, and protect the environment in irrigated rice
production in Vietnam through the reduced use of seeds, nitrogen fertilizer, and
pesticides. It was developed by the International Rice Research Institute and introduced
to farmers in South Vietnam by the Ministry of Agriculture and Rural Development in early
2000 through traditional extension work and mass media. Farm survey data provide
evidence of adoption of 3R3G primarily in terms of lowering seed rates. The resultant
changes in the farm production/cost structure and farmer profits are measured.
Key words: information-intensive technology, technology transfer, farm-level impacts
1. Introduction
In the context of Asian agriculture, ‘rice is life’. Approximately 90% of world rice production of 620 metric
tons in 2005 was grown and consumed in Asia. Only 7% of production is traded. In Bangladesh,
Cambodia, Indonesia, Lao PDR, Myanmar, Thailand, and Vietnam, per capita rice consumption ranges
from 90 to 200 kg per year and accounts for about 50-80% of the caloric intake. Two-thirds of the world’s
poor also live in Asia.
A turning point in Vietnam’s rice history occurred in the mid-1990s when the county was transformed
from an importer to an exporter of rice. By 2005, Vietnam’s rice area of more than 7 million ha covered
75% of the country’s cultivated land and produced 36 million tons of rice, which exceeded domestic
demand. As a result, Vietnam has become one of the world's leading rice exporters. For example,
Vietnam exported four million tons of milled rice in 2004. Meanwhile, there was also increased use of
agrochemical inputs, specifically inorganic fertilizers and pesticide products. Concerns about the
environmental and health consequences of the injudicious use of agrochemicals are extensively
discussed in the literature.3
Yield-increasing and cost-saving technologies are at the centerfold of programs aimed at increasing
food supply and farm household incomes to achieve global food security and reduce poverty. Although
research into varietal improvement is still paramount, there has been increased attention toward
developing technologies (largely crop management strategies) that will result in a reduction in the
injudicious use of agrochemicals without sacrificing yield. Broadly speaking, these crop management
strategies can be categorized as (a) those aimed at increasing yield while largely maintaining input use,
and (b) those aimed at reducing input requirements without sacrificing yield. The technology of interest
here which is commonly referred to as ‘Three Reductions, Three Gains’ (3R3G) falls into the second
broad category. In essence, it is a knowledge-based technology aimed at lowering the cost of growing
rice in irrigated systems (through reduced seeds, nitrogen fertilizer, and pesticides) while maintaining
1 Contributed paper at the 52nd Annual Conference of the Australian Agricultural Resource Economics Society
held at Rydges Lakeside, Canberra ACT, Australia, 5-8 February 2008.
2Associate scientist, impact specialist, and data encoder, Social Sciences Division, International Rice Research
Institute, DAPO Box 7777, Metro Manila, Philippines. All correspondence should be addressed to Zenaida Huelgas,
Email: z.huelgas@cgiar.org.
3See for example, Nguyen and Tran (2003) in http://203.116.43.77/publications/research1/ACF124.html.
ZMHuelgas AARES 2008 Paper
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yield, and improving farmer’s health and better protecting the environment (through the reduced reliance
on agrochemicals).
The 3R3G project evolved from an integrated pest management (IPM) project in which the concept of
not spraying for pests in rice fields the first 40 days after sowing was developed. This concept was based
on research findings that showed that early spraying was unnecessary as any damage from the leaf-
feeding insects (the prime cause of early spraying) did not affect yield (Heong et al 1994). Given the
strength of the research finings, a ‘No Early Spraying’ (NES) media campaign was funded and reached
around 92% of the 2.3 million farmer households in the Mekong Delta in Vietnam. As a result, the
number of insecticide sprays per season dropped by 70% from 3.4 to 1.0, (Huan et al 1999). This was a
remarkable change as farmers responded positively to the challenge posed by the media campaign
The success of the NES experiments, combined with the knowledge that farmers in the Mekong Delta
were applying high seeding rates (200-300 kg/ha) and nitrogen applications of around 150-300 kg/ha,
resulted in the Irrigated Rice Research Consortium (IRRC), with funding support from the Swiss Agency
for Development and Cooperation (SDC), to conduct on-farm research in the province of Can Tho in 2001
to determine the amount by which seed and fertilizer use could be reduced. In the following year, the
Plant Protection Division (PPD) under Vietnam’s Ministry of Agriculture and Rural Development (MARD)
validated the results of the experiments in 11 provinces with matching funds from the Danish International
Development Agency (DANIDA). This study, involving 951 farmers, showed that seeds, fertilizers, and
insecticides can be reduced by 40%, 13%, and 50%, respectively, resulting in marginal yield increases
and increased profits of US$44-58/ha (corrected figures from Huan et al 2005). As a result, the pesticide
management practice of NES was packaged with lower seed rates4 and lower nitrogen use and became
known locally as Ba Giám Ba Tăng or Three Reductions, Three Gains. (See Table 1 for information on
2002 data on farmers’ practice and the scientist-based recommended target rates.) By February 2005, a
national committee was established by MARD to develop plans to scale up implementation of 3R3G. In
2006, MARD allocated about US$230,000 to 64 provinces, specifically for Ba Giám Ba Tăng
implementation.
The national program used standard extension activities combined with a quite elaborate and creative
mass media campaign. Through a multi-stakeholder participatory planning process, a campaign package
was developed to reach and motivate large numbers of rice farmers in the Mekong Delta (Huan et al
2005). It consists of communication media (TV, radio, print, and demonstrations) and materials (soap
operas, leaflets, pamphlets, and farmer field days) geared toward increasing the farmers’ ability and
motivation to modify their resource management practices by adopting the relatively knowledge-intensive
technology. The strategy was to change a farmers’ attitude toward input use from one of ‘more is better’
to one of ‘less is more sensible’ through a number of information-delivery systems. In particular, these
included billboards along main roads, soap operas aired in national radio and television stations,5 and
public amplifiers in the villages which were used to replay the radio broadcasts before daybreak, just
before the farmers go to the rice fields. It became nearly impossible for a farmer not to hear about 3R3G.
4It will be shown later in the discussion that although 3R3G was inspired by NES, seed reduction is its most
important component. Further, unforeseen recurrence of brown plant hopper “outbreak” and the diseases it carried in
2005 compromised the benefits of 3R3G.
5Funding support for various radio and television soap operas came from The Rockefeller Foundation and The
World Bank (US$131,800) with IRRI as project proponent. One specific radio program is the “Chuyen Que Minh” or
“My Homeland,” which is well described by Escalada and Heong (2007).
ZMHuelgas AARES 2008 Paper 3
The principal scientists behind the 3R3G received recognitions and awards from the Vietnamese
government and the SDC, suggesting that the technology succeeded in making a difference in terms of
farmer (and environmental) well-being. The aim of this paper is to provide some preliminary estimates of
the economic impact at the farm level. In particular, it addresses the questions:
(a) How effective was the media campaign in promoting 3R3G awareness and adoption?
(b) Did adoption result in significant reductions in input use and thereby lower costs and
increase profits?
2. The data and analytical framework
2.1 South Vietnam (Mekong Delta)
Vietnam's Mekong Delta is at the end of the world's 12th longest river. Arising from the Himalayas, the
Mekong River supplies the tropical wetlands of Vietnam with rich alluvial deposits making the soil
sufficiently fertile that the area is home to 15 million people. The intense green of cultivated rice paddies
can be seen across the Mekong Delta, threaded through by an intricate web of irrigation and drainage
canals.6 The Mekong Delta has 13 provinces that altogether accounted for about 52% of total national
rice output of 36 million tons in 2005. Generally, two rice crops are grown per year. The national yield
average in 2005 was 5 tons/ha.
2.2 The data
Household surveys were conducted in the provinces of An Giang and Can Tho in July-August 2006. For
each province, three districts and three villages per district were selected. Sample sizes at each
geographical level were proportioned to rice area. Farmers interviewed were chosen at random in each
village. Thus, a stratified/random sampling procedure was used to select 200 farmers in each province
(Table 2). The questionnaire used was well-structured and designed to collect input-output data and
information on the knowledge and perceptions of farmers with regard to 3R3G in particular and to rice
farming in general. The data were collected for two seasons –the dry season (winter-spring 2005-06) and
the wet season (summer-autumn 2006)—by the staff of the Faculty of Economics at An Giang University,
An Giang Province, Vietnam. The farm survey was complemented by farmers’ focus group discussions
(FGD); key informant interviews (KII) of provincial/district government officials, extension workers, and
seed growers; and collection of price data from agricultural chemical retail shops in all the provinces.
2.3 Pathway to higher farm profits
The 3R3G technology is not a physical good (such as in the case of a new high-yielding rice variety) but
rather a package of input management recommendations that farmers can use in their profit-maximizing
or input use-decision making process. The 3R3G technology capitalizes on the synergistic effects of
reducing three inputs together without sacrificing yield – that is, if seed rates are lowered, less fertilizer is
required which, individually and jointly, makes the crop less attractive to pest, reducing the need for
insecticides for the whole cropping season. Further, the adoption of NES also discourages pest
population buildup because not only is early spraying unnecessary in terms of yield benefits (as stated
above) but, by destroying pest predators, it can lead to pest resurgence problems. In other words, the
more a farmer sprays, the more a farmer may need to spray. As such, the benefits of the 3R3G
technology package should manifest in reduced input use intensities without yield loss and, therefore,
reduced costs and hence higher profits.
The 3R3G package was taken up by the Vietnamese MARD - first at the provincial level and then at
the national level. Perhaps, part of the reason for MARD’s interest in 3R3G was that it complemented
other (much larger) R&D programs aimed at increasing the use of seeders and certified (good) seeds. As
6 Source: http://earth.esa.int/cgi-bin/satimgsql.pl?pf=473
ZMHuelgas AARES 2008 Paper
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discussed below, data from the 2005-06 survey showed that seed reduction was the component that
contributed most to overall gains from 3R3G.
In addition to the development and promotion of other technologies, the adoption of one or more of
the components of 3R3G was influenced by a range of biotic and abiotic stresses. For example, the
marked resurgence of an insect called brown plant hopper in the Mekong Delta in 2005 could have had a
significant negative impact on the farmers’ willingness to reduce insecticide use. In addition, farmers will
react to changes in the price of inputs or output in terms of increased or reduced input use.
2.4 Definition of adopters and non-adopters
A requisite to measuring impact is being able to establish the ‘with and without’ technology scenarios. In
this case, it is done by establishing and comparing two groups of farmers who have similar
characteristics, except with respect to their uptake of 3R3G. In other words, the two groups are the
‘adopters’ and ‘non-adopters’. Since 3R3G is basically a suite of crop management technologies
comprising three components, it is possible for some farmers to fully adopt all three components and
others to partially adopt one or a paired-combination of the components. Indeed, in this instance, there
were very few farmers who reported to be ‘full’ adopters of the technology. As such, adopters are defined
as farmers who have stated that they heard about and believed in the principles of 3R3G and have, to
some degree at least, taken up one or more of the 3R3G recommendations and lowered their seed,
nitrogen, and/or pesticide use. Conversely, the non-adopters group are farmers who stated that they (a)
have never heard about 3R3G, (b) have heard about 3R3G but do not believe in the principal
recommendations, or (c) have heard about and believed in the principles of 3R3G but are not willing to
take the risk of changing their farming practices along the lines of those recommended under the 3R3G
package.
2.5 Comparison of input rates, yield, costs, and income
The first step to finding evidence of economic impact is to look at farm-level data and examine changes in
practices (input use) and performance (yield, costs, and income). Simple mean comparisons between
adopters and non-adopters were done to measure such changes.
Moving forward, multivariate analyses involving production function frontier estimations to establish
efficiency scores for adopters versus non-adopters will be done after data cleaning of the relevant
variables is completed. Farm-level results shall be used in the second (and final) step which shall
measure the economic benefits to society in terms of internal rate of return (IRR) using the DREAM7
model.
3. Results
All farms considered in the analyses were direct seeded; the few transplanted farms were dropped from
the analysis. Also excluded from the analysis in the wet season were farms with incomplete output
information because interviews were done prior to harvesting. The following discussion refers to Tables
3-6.
3.1 Awareness and adoption
Strategic media campaign and traditional extension work promoting 3R3G succeeded in creating more
than 80% awareness regarding the teachings and benefits of reducing the three key inputs–seed,
fertilizer, and pesticides. Even those who have not participated in farmers’ trainings and demonstration
trials were able to enumerate the reduction teachings. The media was an effective tool in changing
7 DREAM, or Dynamic Research EvaluAtion for Management, is a menu-driven software package for evaluating
the economic impacts of agricultural research and development (R&D). Users can simulate a range of market,
technology adoption, research spillover, and trade policy scenarios based on a flexible, multi-market, partial
equilibrium model. For more information, please go to http://www.ifpri.org/dream.htm.
ZMHuelgas AARES 2008 Paper 5
farmers’ attitude (and maybe beliefs also) regarding the optimal rates of seeds and fertilizer and timing of
insecticide application. However, it takes more than awareness to affect practices. Farmers need to
have the minimum knowledge and skills to apply them and be convinced that such a change will work to
their advantage – this is where ‘hard core’ extension through the work of agricultural technicians plays an
important role. The media campaign, however, made it easier for the technicians to motivate farmers in
taking small risks by reducing inputs gradually from one season to the next. This eventually led to
adoption. Equally important considerations to adoption are farmers’ assessment of risks imposed by the
vagaries of weather, incidence of migratory pests, and fluctuations in input/output prices. Natural
disasters causing floods, migration of pests into the area, and unfavorable prices, singularly or in
combination, will discourage farmers to reduce seed, fertilizer, and pesticides.
Partial adoption was most common, with reductions in the seed rate being the single component with
the highest adoption rate. This is a positive outcome because if the farmer is able to reduce seed rates,
then adoption of the other two components may follow as there is less pest pressure and reduced
fertilizer requirements (Heong 2006). However, as was apparent from the field visits and discussions with
key informants, the 3R3G was being promoted hand-in-hand with two other programs by MARD, namely,
the provision of a reliable supply of affordable, good seeds and promotion of mechanical seeders. Seed
reduction adoption rate is 11 percentage points lower in Can Tho (34%) than in An Giang (45%). This
could be because of lower access to certified, registered or local seed, which are of better quality than
previously harvested seeds. Indeed, the farmers indicated that they would further reduce seed rates in
the future as quality seeds and mechanical seeders become increasingly available. In other words,
indications are that the reduced seed rate is not solely attributable to 3R3G.
3.2 Changes in input use
Seeds. The lowest seed rate (153 kg/ha) was reported by adopters in An Giang Province during the
dry season of 2005-06, whereas the highest seed rate (200 kg/ha) was reported by farmers in Can Tho in
the wet season (Tables 5 and 6). These rates were both well above the science-based recommendation
of 100 kg/ha (Table 1). Most of these adopters indicated that they will continue reducing seed rate in
increments of about 10-20 kg/ha in the succeeding seasons if weather conditions are favorable and there
is no significant yield sacrifice. This is consistent with the overall MARD strategy of allowing farmers to
slowly achieve seed rate target year-by-year. As such, this continued fall over time need to be
considered in an analysis of a temporal flow of benefits from the adoption of 3R3G recommendations.
Fertilizer. The mean values for elemental nitrogen and elemental phosphorus application for both
adopters and non-adopters of 3R3G in An Giang and Can Tho were close to the science-based
recommendations of 110 kg/ha and 40 kg/ha, respectively (Table 1). For example, in An Giang, farmers
were using 108 kg/ha of elemental nitrogen and 30 kg/ha of elemental potassium (Table 5). Given that
the adopters and non-adopters were both applying these fertilizers at levels close to the recommended
rates, it is not surprising that there is limited evidence of a significant difference between adopters and
non-adopters (Tables 5 and 6). The only exception was in the case of adopters in An Giang who applied
around 8 kg/ha less elemental nitrogen in the dry season than did the non-adopters (Table 5).
In contrast, the use of elemental phosphorus was 35-80% higher than the recommended rate of 30 kg/ha
(Table 1), with the highest level of use (54 kg/ha) being reported for adopters of 3G3R in An Giang.
Nevertheless, there was no significant difference between adopters and non-adopters in either province
(Tables 5 and 6).
Pesticides. The data suggest that adopters of 3R3G reduced the use of insecticides, fungicides, and
even molluscicides (for snail control). Adopters in the two provinces spent US$8-12/ha/season less on
pesticides than did the non-adopters (Tables 5 and 6). As mentioned earlier, 3R3G had its roots in NES.
However, rather than promoting NES per se, the message delivered in the media campaign was one of a
general reduction in the use all pesticides as it is a relatively less complicated NES message to abstain
from applying insecticides in the first 45 days after planting.
ZMHuelgas AARES 2008 Paper
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Further discussions with farmers and district technicians revealed an active integrated pest
management (IPM) program in the region prior to 3R3G. IPM taught farmers to practice judgment in
assessing pest situations and use pesticides judiciously and to adopt NES. Since 3R3G can be regarded
to have only reinforced the IPM teaching, then the benefit of a reduction in pesticide use cannot be fully
attributed to 3R3G.
3.3 Yield
The national yield average for Vietnam in 2005 was 4.9 tons/ha. Yields are naturally much higher in
irrigated (favorable) than in rainfed (less favorable) areas. South Vietnam is a prime rice-growing area
because of high alluvial deposits that feed the paddy soils along the trail and tail end of the Mekong River.
The provinces along the river are expected to have higher yields. Also, yields are much higher in the dry
season because of greater solar radiation that results in more and heavier grains. This is supported by
the survey data which show that, in the dry season, average yields for An Giang and Can Tho were 7.7
tons/ha and 7.8 tons/ha, respectively. Yields were much lower in the wet season, averaging 5.8 tons/ha
and 5.2 tons/ha for An Giang and Can Tho, respectively. Nevertheless, the wet season yields for these
two provinces were still higher than the national average.
As stated above, the aim of the 3R3G technology is to reduce the use of seed, nitrogen fertilizer, and
insecticides without sacrificing yield. Hence, it can be hypothesized that the adopter’s yield should be
equivalent to the yield obtained by non-adopters. This proved to be true for An Giang in both seasons
(Table 5). In Can Tho, however, yield appeared to have been compromised, with non-adopters yield
being around 350 kg/ha (440 kg/ha) higher than that of the adopters in the dry (wet) season (Table 6).
This significant difference in yield could be the result of the lower seed rate, poorer seed quality, and the
reduced use of pesticides. However, given the importance of the yield difference in assessing the
economic benefits of 3R3G, further investigation will be undertaken to more fully understand the cause of
the difference.
3.4 Production cost
Costs were aggregated into two components–labor and materials (Tables 5 and 6). Labor cost consists
of paid-out labor costs (including meals) plus imputed family labor costs. Material costs include seed,
fertilizer, pesticides, fuel, and oil. Roughly, labor was 36-42% of total costs and materials, 58-64%.
The hypothesis is that adopters should have lower per-unit cost or average cost, which theoretically
mirrors a lower marginal cost. Average cost is total cost divided by total production. In absolute terms,
farms in An Giang operated at a higher per-unit cost (US$64-108) than farms in Can Tho (US$57-95).
The difference between provinces can be explained mostly by higher labor cost in An Giang due to the
more intense land preparation activity and higher wage rates. There are also seasonal differences in the
cost of production. The average cost of production is lower in the dry season than in the wet season
crop. This is because of lower labor inputs associated with harvesting. Lodging at harvest time in the wet
season was quite prevalent which resulted in greater use of labor and higher wage rates induced by
increased demand. In An Giang, for example, the average costs in the wet season were higher than
those in the dry season by US$26-38.
Finally, the ratios of average cost to paddy price farms suggest 29-62% profit margin. However, as
shown in the discussion below, in terms of net income per unit area, the returns were still low.
3.5 Net income and poverty
Net income was computed as the difference between value of production and cost of production per unit
of land (ha). It indicates the importance of the rice crop in the financial well-being of the rice farming
household. Net income figures are more meaningful when compared with the poverty line and whether
additional income from adoption of 3R3G can contribute to alleviation.
ZMHuelgas AARES 2008 Paper 7
Given the World Bank poverty measure of US$1 a day and a family household size of 5 (survey average
for household size ranged from 4.6 to 4.9), then household annual income poverty line would be
US$1,825.
In An Giang, annual net incomes/ha were US$1,092 for adopters and US$883 for non-adopters.
Given the average farm size of two ha and a household size of five the resulting per capita income per
day were US$1.20 for adopters and US$0.97 for non-adopters. These are within close range of World
Bank’s poverty line of US$1 per capita per day. Noteworthy is the observation that adopters exceeded
the rice incomes of non-adopters by $418 per year. This increase in income is sufficient to push the
farmer over (even if just marginally) the poverty line. The additional incomes could be reinvested in the
farm or they may be used to improve the health and education status of the household or social/cultural
activities. Hence, the additional income from adoption of 3R3G may have high ‘social value’ – although
assessing the social impact of the 3R3G-induced change in income is beyond the scope of this study. Of
significance is the fact that the net income benefits received by the adopters in An Giang were bigger in
the wet season (US$236/farm) than in the dry season, $184/farm, despite the lower yields.
In Can Tho, the net income per farm (per capita per day) is estimated to be US$2,047 (US$1.12) for
adopters and US$2176 (US$1.19) for non-adopters. Hence, both adopters and non-adopters are above
the poverty line, albeit marginally. However, these results are counter-intuitive in that they suggest non-
adopters are better off than the adopters. As stated above, the reasons for the counter-intuitive results
need further investigation.
3.6 Future analysis: technical efficiency and IRR
To further the search for economic impacts, a frontier production function will be specified in order to
estimate and compare efficiency scores between adopters and non-adopters. While the yield-increasing
technologies shift the production frontier, NRM technologies “push” a farm or firm toward the frontier
through more efficient use of inputs. They basically reduce the gap between actual and potential/frontier
yields. In an empirical study, both frontier shifts and efficiency gains should lead to an outward shift in the
marginal cost or supply curve. This shift is the “change” component in economic impact analysis and the
estimation of IRR within a consumer surplus framework and DREAM. Estimates of cost reductions and
adoption rates were to be used as well in the estimation of IRR.
4. Conclusion
Evidence of economic impact of 3R3G at the farm level shows a US$92/ha to US$118/ha increase in net
incomes in An Giang. This is equivalent to a US$5-17 per ton fall in the average cost of rice paddy.
However, while these results would suggest that the 3R3G program has been successful, the results for
Can Tho do not support this finding. Hence, while the total economic benefit for An Giang can be
estimated, the An Giang farm-level data cannot be used as a proxy for the rest of the Mekong Delta as it
could lead to a gross overestimation of the benefits. As such, the next steps are to explore what lies
behind the counter-intuitive results for Can Tho and to complete the data cleaning and analysis for a third
province, Soc Trang. Once this has been done, it may be possible to combine the farm-level data for the
three provinces and obtain a measure of the returns to research. Issues of attribution will also need to be
addressed.
ZMHuelgas AARES 2008 Paper
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5. References
Escalada MM, Heong KL. 2004. The case of using mass media: communication and behavior change in
resource management. New Directions for a diverse planet. In: Proceedings of the 4th International
Crop Science Congress, 26 Sep – 1 Oct 2004, Brisbane, Australia. (on CD-ROM)
Escalada MM, Heong KL. 2007. Environmental radio soap opera for rural Vietnam. Paper presented at
Radio Asia 2007, 19-22 June 2007, Singapore,. Electronic copy available at
http://devcompage.files.wordpress.com/2007/12/mescaladaheong-asia-radio-paper.pdf.
Heong KL. 2006. Transforming research to benefit millions: The case of the 3R3G program in Vietnam.
Division Seminar, Social Sciences Division, 23 Jun 2006, IRRI, Los Baños, Philippines.
Heong KL, Escalada MM, Mai V. 1994. An analysis of insecticide use in rice: case studies in the
Philippines and Vietnam. Int. J. Pest Manage. 40: 173-178.
Huan NH, Mai V, Escalada MM, Heong KL. 1999. Changes in rice farmers’ pest management in the
Mekong Delta, Vietnam. Crop Prot. 18: 557-563.
Huan NH, Thiet LV, Chien HV, Heong KL. 2005. Farmers’ evaluation of reducing pesticides, fertilizers
and seed rates in rice farming through participatory research in the Mekong Delta, Vietnam. Crop
Prot. 24: 457-464.
MacKenzie D. 1995. Seeing is believing. New Scientist. 26 Aug 1995.
6. Acknowledgment
Survey data were collected by the faculty staff of Dr. Nguyen Tri Khiem of An Giang University, An Giang,
Vietnam. The enumerators were DTK Loan, TM Hai, DA Tai, DH Vu, NL Duyen, PN Trieu, NVT Chi, VM
Sang and LTT Huong. At IRRI, Dr. KL Heong provided technical comments and Ms. Tess Rola edited the
manuscript.
ZMHuelgas AARES 2008 Paper 9
Table 1. Three Reductions-Three Gains (3R3G) Technology target seed, fertilizer, and pesticide
use rates.a
Farmers’ practice
in 2002b
Target for
dry season
(winter-spring)
Target for
wet season
(summer-autumn)
Seed (kg/ha)
200-350
70-100
100-120
Fertilizer
Nitrogen (kg/ha)
Potassium (kg/ha)
Phosphorus (kg/ha)
150-300
No data available
No data available
120
30
30
100
50
30
Insecticide Spray 10-15 days
after planting NES first 40 days after planting
Fungicide “Calendar”
spraying Use fungicide when blast symptoms are
visible at booting stage
(at 60 days after planting)
aThese are scientist-based recommended rates. The Ministry of Agriculture and Rural Development was
aware that achieving these rates will take a few years so that annual targets were adjusted accordingly.
bElicited from Plant Protection Division provincial, district, and village directors during key informant
interviews in June 2006 and March 2007.
Table 2. Sample-distribution,a by survey site and cropping season,b
South Vietnam, crop year 2005-06.
An Giang
Can Tho
Dry season 2005-06 195 194
Wet season 2006 184 191
a Two hundred were interviewed in each province. Transplanted farms and
those with incomplete information were dropped from the analysis.
b Very few planted a third (second wet season) crop.
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ZMHuelgas AARES 2008 Paper 11
Table 3. Awareness and adoption rates (%) of 3R3G as reported by farmers,
South Vietnam, crop year 2005-06.
An Giang
Can Tho
Awareness 86 83
Practice change
• Reduced seeds 45 34
• Reduced nitrogen/fertilizer 35 25
• Reduced insecticide/pesticide 39 24
Adopters (one or more of above reduction) 47 36
Non-adopters 53 64
Number of farmers reporting
195
194
Table 4. Primarya and secondarya sources of information on 3R3G, South Vietnam,
crop year 2005-06.
Adopter Non-
adopter ALL Adopter Non-
adopter ALL
Primary Secondary
AN GIANG
Agric. technician 25 10 35 18 11 29
Radio & TV 24 32 56 35 19 54
Othersb5 4 10 32 20 53
All sources 91 76 167 85 50 136
CAN THO
Agric. technician 19 13 32 7 10 17
Radio & TV 22 42 65 29 28 58
Othersb2 2 4 5 20 25
All sources 69 92 161 41 58 100
a Primary sources refer to individuals or media from whom/which farmers heard and learned
about 3R3G for the first time. Secondary sources are those from whom/which farmers heard
about 3R3G in other times. Some farmers reported more than one secondary source.
b Co-farmers, relatives, and input suppliers.
Table 5. Input use, cost, and income comparisons, adopters vs non-adopters of 3R3G, An Giang, South Vietnam, crop year 2005-06.a
Adopter Non-adopter
Input/cost
reductions Adopter Non-adopter
Input/Cost
reductions
(A) (B) (A-B)
Level of
statistical
significance (A) (B) (A-B)
Level of
statistical
significance
Dry season, 2005-06 Wet season, 2006
Number of cases 91 104 87 97
Seed rate (kg/ha) 153.307 187.137 -33.830 0.000 154.438 194.257 -39.819 0.000
Elemental nitrogen (kg/ha) 107.804 115.984 -8.180 0.079 108.917 122.987 -14.070 0.029
Elemental potassium (kg/ha) 30.172 30.148 0.024 0.989 30.334 31.873 -1.539 0.506
Elemental phosphorous (kg/ha) 53.907 48.418 5.489 0.151 54.995 48.964 6.031 0.105
Herbicide cost (US$/ha) 14.921 14.931 -0.010 0.994 15.078 16.576 -1.498 0.380
Insecticide cost (US$/ha) 20.262 29.851 -9.589 0.009 21.544 27.407 -5.863 0.163
Fungicide cost (US$/ha) 44.037 49.862 -5.825 0.339 41.836 53.732 -11.896 0.044
Molluscicide cost (US$/ha) 10.974 12.137 -1.163 0.533 8.186 9.827 -1.641 0.302
Yield (t/ha) 7.719 7.634 0.085 0.593 5.87 5.708 0.162 0.359
Average cost (US$/t) 64.404 70.283 -5.879 0.061 90.144 108.027 -17.883 0.001
Paddy price (US$/t) 151.571 146.079 5.492 0.000 156.149 151.63 4.519 0.016
Income: gross (US$/ha) 1,170.26 1,115.63 54.623 0.034 912.9 863.69 49.210 0.071
Cost: labor (US$/ha) 185.345 189.99 -4.645 0.643 211.23 232.52 -21.298 0.034
Cost: materials (US$/ha) 300.371 333.291 -32.920 0.003 293.357 340.437 -47.080 0.000
Cost: total (US$/ha) 485.716 523.282 -37.566 0.029 504.583 572.961 -68.378 0.000
Income: net (US$/ha) 684.54 592.351 92.189 0.004 408.318 290.729 117.589 0.001
a All monetary values are in 2006 prices.
ZMHuelgas AARES 2008 Paper
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Table 6. Input use, cost, and income comparisons, adopters vs non-adopters of 3R3G, Can Tho, South Vietnam, crop year 2005-06.a
Adopter Non-adopter
Input/cost
reductions Adopter Non-adopter
Input/cost
reductions
(A) (B) (A-B)
Level of
statistical
significance (A) (B) (A-B)
Level of
statistical
significance
Dry season, 2005-06 Wet season, 2006
Number of cases 69 125 68 123
Seed rate (kg/ha) 195.273 211.324 -16.051 0.002 200.041 219.036 -18.995 0.001
Elemental nitrogen (kg/ha) 101.213 98.425 2.788 0.604 108.123 101.747 6.376 0.260
Elemental potassium (kg/ha) 26.667 27.561 -0.894 0.662 29.158 29.82 -0.662 0.769
Elemental phosphorous (kg/ha) 39.394 38.537 0.857 0.810 44.014 44.724 -0.710 0.852
Herbicide cost (US$/ha) 16.459 13.884 2.575 0.392 16.458 14.782 1.676 0.581
Insecticide cost (US$/ha) 18.598 29.422 -10.824 0.059 18.892 28.103 -9.211 0.004
Fungicide cost (US$/ha) 34.603 42.52 -7.917 0.103 30.703 40.225 -9.522 0.007
Molluscicide cost (US$/ha) 9.684 11.432 -1.748 0.258 7.835 15.802 -7.967 0.012
Yield (MT/ha) 7.615 7.968 -0.353 0.066 4.93 5.37 -0.440 0.022
Average cost (US$/MT) 57.14 59.943 -2.803 0.252 93.543 94.849 -1.306 0.748
Paddy price (US$/MT) 152.22 155.126 -2.906 0.079 148.231 150.005 -1.774 0.123
Income: gross (US$/ha) 1,160.22 1,236.73 -76.511 0.020 733.388 804.606 -71.218 0.015
Cost: labor (US$/ha) 161.532 175.596 -14.064 0.035 168.41 188.08 -19.670 0.002
Cost: materials (US$/ha) 265.588 291.772 -26.184 0.053 274.583 297.685 -23.102 0.063
Cost: total (US$/ha) 427.12 467.368 -40.248 0.013 442.991 485.762 -42.771 0.005
Income: net (US$/ha) 733.095 769.358 -36.263 0.262 290.398 318.844 -28.446 0.350
All monetary values are in 2006 prices.
ZMHuelgas AARES 2008 Paper 13
Fig. 1. Pathway to higher farm profits for “Three Reductions, Three Gains” technology.
Reduced
Seeds
Nitrogen
Pesticide
Reduced
Cost
Weather Market
Higher
Profits
3R3G
ZMHuelgas AARES 2008 Paper
14
