Fantastic Rice Yields: Fact or Fallacy.

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"The doctor of the future will give no medicine, but will interest his patients in the care of the human frame, in diet and in the cause and prevention of disease."
- Thomas Edison

Salt water rice

Sonic Bloom doubles rice yields in Indonesian trials.

  For more information see the continuation of these articles at Fantastic Rice Yields, Page 2.

Also see the article Rice in Asia: Too Little Iron, Too Much Arsenic.

 

 

The Institute of Science

 in Society

Science Society Sustainability http://www.i-sis.org.uk

General Enquiries sam@i-sis.org.uk Website/Mailing List press-release@i-sis.org.uk ISIS Director m.w.ho@i- sis.org.uk
 

ISIS Press Release 02/07/04

Rice wars

Rice, the staple food crop for more than half the world's population, among them the poorest, is the current target of genetic modification, an activity that has greatly intensified after the rice genome was announced two years ago (see "Rice is life" series, SiS 15, Summer 2002). Since then, all major biotech giants are investing in rice research.

At the same time, a low-input cultivation system that really benefits small farmers worldwide has been spreading, but is dismissed by the scientific establishment as "unscientific". This is one among several recent innovations that increase yields and ward off disease without costly and harmful inputs, all enthusiastically and widely adopted by farmers.

A war is building up between the corporate establishment and the peoples of the world for the possession of rice. The food security of billions is at stake, as is their right to grow the varieties of rice they have created and continue to create, and in the manner they choose.

This extended series will not be appearing all at once, so look out for it.

Fantastic Rice Yields Fact or

 Fallacy?

A low-input rice cultivation system invented in Madagascar and spreading all over the world is apparently exposed as without scientific basis. Dr. Mae-Wan Ho investigates

Sources for this report are available in the ISIS members site. Full details here

Rice feeds more than half the world's population, but yields of the crop have been levelling out, and 400 million are said to endure chronic hunger in rice-producing areas of Asia, Africa and South America. According to the United Nations, demand for rice is expected to rise by a further 38% within 30 years. To call attention to the problem, 2004 has been declared the International Year of Rice. "Rice is on the front line in the fight against world hunger and poverty", said Jacques Diouf, director-general of the UN Food and Agriculture Organisation.

Many farmers all over Asia have already identified low-input, sustainable solutions to the problem (see other articles in this series).

One simple method that boosts rice yields at much lower cost to farmers originated outside Asia. The System of Rice Intensification (SRI) developed in the late 1980s in Madagascar, has since been spreading to other parts in Africa and to Asia. In Madagascar itself, some 100 000 farmers have converted to it. And more than 20 other countries, from Bangladesh to Thailand, have either adopted SRI, or field tested it, or expressed firm interest. In Cambodia, SRI was unheard of in 2000, but by 2003, nearly 10 000 farmers had converted to it, and that figure may reach 50 000 this year.

Advocates of SRI routinely report yields up to twice or more those achieved by conventional agriculture.

However, eminent agronomists are dismissing those claims as "poor record keeping and unscientific thinking"; and results of new field trials, published in March 2004 in the journal Field Crop Research, appear to support this view.

History of SRI

SRI was developed nearly 20 years ago by Father Henri de Laulanié, a Jesuit priest who worked with farming communities in Madagascar from 1961 until his death in 1995. In conventional rice growing, the plants spend most of the season partially submerged in water. During a 1983 drought, many farmers could not flood their paddy fields, and de Laulanié noticed that the rice plants, in particular, their roots, showed unusually vigorous growth.

From this and other observations, de Laulanié developed the SRI practice: rice seedlings are transplanted quickly when young, spaced widely apart, and most importantly, the rice fields are kept moist but not flooded. In addition, he emphasized using organic compost over chemical fertilizers, so that poor and rich farmers alike could practise SRI.

Norman Uphoff, a political scientist and director of the International Institute for Food, Agriculture and Development at Cornell University in Ithaca, New York, stepped into the picture in 1993. He was part of a team trying to find alternatives to the damaging types of slash and burn agriculture that was destroying Madagascar's rainforest. It was clear to Uphoff that if rice yields in the area could be increased from about 2 tonnes per hectare, as it was then, a lot of forest could be saved. He came across de Laulanié's not-for-profit organisation, `Tefy Saina' meaning "to improve the mind".

Uphoff was looking for a yield of 4 tonnes per hectare, and when he heard them say they could get 5 or more, he did not believe them. But such doubts vanished once farmers in the rainforest regions started using SRI. The results were stunning. "By the end of the second growing season we were getting 8 tonnes per hectare". In 1997, Uphoff began promoting SRI throughout Asia.

Why SRI benefits farmers, consumers and the environment

SRI's benefits lie in important differences from conventional rice growing practice, which, proponents believe, interact synergistically to give high yields.

First, seedlings are transplanted at 8-12 days instead of 15 to 30 days after germination, singly as opposed to 2-3 seedlings, and spaced up to 6 times apart compared to traditional practice; for example, up to 50cm x 50cm instead of 20cm x 20cm. This represents a substantial saving on seeds, up to ten-fold or more in some cases. The increased spacing has the effect of encouraging tillers or side shoots to develop quickly, giving many more rice-forming panicles per plant.

Second, the fields are kept moist during all or most of the growing season instead of being flooded continuously. This tremendous saving on water is particularly important in areas of water scarcity, and avoids the damages of salination that accompanies over-irrigation. It also encourages vigorous root development, which in turn gives more vigorous growth of the rice plants.

Third, no herbicides are used. Weeding is done with or a simple rotary hoe, which returns the weeds to the soil as green manure. This financial saving is offset by increased labour, but labour shortage is seldom a problem for farmers in the Third World, and weeding becomes less arduous in successive years. Giving up herbicides is a health bonus for all concerned: the farm worker most of all, and the consumer; and there is no pollution of the environment and ground water.

Fourth, no mineral fertilizers are used, only liberal application of organic compost. This financial saving is accompanied by an improvement to the quality and fertility of soil, reducing runoff, and improving its water-retaining properties.

Despite its early start in Madagascar, SRI has only begun in other countries since 2000, and already, positive results are pouring in (see "Does SRI work?" this series).

Critical scientists

Major critics of SRI include John Sheehy, an agronomist at the International Rice Research Institute (IRRI) in Manila, the Philippines. He said most SRI field studies have appeared in conference proceedings and other publications not subject to peer review.

That is hardly surprising given the lack of interest from mainstream scientists, and its relatively recent uptake in countries other than Madagascar.

In March 2004, Sheehy, together with IRRI researcher Shaobing Peng, A. Dobermann of the University of Nebraska, Lincoln in the United States, and other researchers from Sheffield University in the UK; from Yangzhou University, Jiangsu, Hunan Agricultural University, Changsha, and Guangdong Academy of Agricultural Science, Guangdong, China, published their first trials of SRI under the telling title, "Fantastic yields in the system of rice intensification: fact or fallacy?"

This report was written up as a news feature in the top journal Nature, under the yet more telling title, "Feast or famine?" asking whether SRI was a diversion from "more promising approaches" to increasing yield such as genetic engineering.

Sheehy and coworkers planted a single rice cultivar, shanyou 63, at three experimental stations in Hunan, Guangdong and Jiangsu provinces of China, using SRI and conventional best practice in living-room-sized (8 x 5m) plots in the same fields. Weeds were suppressed with herbicides on the conventional plots but pulled by hand in the SRI plots. SRI plots received extra rapeseed cake fertilizer. Conventional plots were flooded as usual; SRI plots were kept saturated and only flooded 2 weeks before maturity.

Overall, no significant differences were found between the two cropping systems. SRI yielded 8.5% higher in Jiangsu, but 8.8% worse in Hunan.

Dobermann was reportedly "not surprised", as he said every component of SRI had been studied before and found to have little effect. The results also fit Sheehy's theoretical calculation of how much rice a field can produce, an upper limit set by the amount of sunlight falling on it. Based on weather data for Madagascar, Sheehy calculated theoretical maximum outputs for areas that have reported the most impressive yields of 21 tonnes/ha under SRI. By his estimates, the yields are as much as 10 tonnes more than is possible. "You can't get out more than gets put in," he reportedly said.

They concluded that, "SRI has no major role in improving rice production generally".

That was a remarkable sweeping dismissal of the extensive research and trials done by both scientists and farmers on numerous rice varieties in 19 countries over two or more growing seasons. Especially so, when the conclusions are based on the results of limited trials of a single variety for only one growing season.

Riposte

Chinese scientists have experimented with SRI since 2000, and their experience had indicated that not all varieties responded to SRI, and that responses improve in successive seasons. Dobermann himself had referred to the possibility of confounding effects when SRI was compared to traditional systems that did not represent the current "best practice". Of course, what is best practice for corporate agriculture is not necessarily best practice for the farmer.

Thus, Sheehy and workers could have stressed the obvious benefits to small farmers, consumers and the environment, even from the results of their own trials. They have obtained the same yields with less than half the seeds in SRI, with no inputs of herbicides, and substantial saving on water.

Norman Uphoff pointed out, in a detailed rebuttal to appear in Field Crop Research, that Sheehy and colleagues have simply not followed the SRI practice in their trials. It did not include the measures recommended for water management and weeding to ensure active soil aeration. Moreover, the high concentrations of chemical fertilizers used with the putative SRI plots (180-240 kg N/ha) would simply have inhibited the soil activity that enhances plant nutrition and growth.

"The merits of SRI methods have been validated by scientists at leading institutions in China, India and Indonesia, the largest rice-producing countries in the world," he remarked.

Why are scientists in research stations failing to replicate the enormous yield gain with SRI methods obtained by farmers? For example, IRRI started trials with SRI at Los Baños in 2002, and obtained a yield of only 1.44t/ha; and the next season, it was still just 3t/ha. Yet, concurrent SRI trials in the government's Agricultural Training Centre in Mindanao, using three varieties (PSBRc18, 72H and 82) yielded an average of 12t/ha.

When asked by IRRI staff why this discrepancy occurred, Uphoff suggested that IRRI's on-station soils, after decades of monocropping and application of fertilizers, insecticides, fungicides, herbicides etc., might be "almost dead", and hence unable to respond to SRI practices, which depend on increasing the abundance and diversity of soil microorganisms to enhance plant growth and health.

The basis for dismissing the high yields obtained in some parts of Madagascar as "fallacy" is highly questionable. It rests on a `model' for predicting theoretical maximum yield using `constants' derived solely from empirical observations on conventionally grown crops, which have no independent justification in terms of the plant's metabolism. For example, biomass accumulation depends on the balance between photosynthesis (which builds up biomass) and respiration (which decreases it), and that can change under different conditions. A healthy plant is also more efficient in using energy and accumulating biomass than an unhealthy one.

An indication that yields more than 20 tonnes/ha may not be "impossible" is that such yields have been recorded for rice growing systems in China in historical times.

Professor Yuan Longping, an expert in breeding high-yielding hybrid rice, who brought SRI to China, stated, "According to the estimates of most plant physiologists, rice can use about 5% of solar energy through photosynthesis. Even if this figure is discounted by 50%, the yield potential of rice would be as high as 22- 23t/ha in temperate regions."

Uphoff maintained that the critics' assumptions are too firmly rooted in conventional practice. Models for estimating maximum yields will not necessarily translate to SRI. "The coefficients for the calculations are based on plants with stunted root systems. SRI plants have extensive root systems," he said.

Nor will single-season trials reveal the full potential of SRI, because over time, better oxygenation leads to the build-up of soil bacteria that interact with the roots and improve the condition of the soil. Even if SRI fails to increase yields when first introduced, as was the case in Thailand, for example, further seasons will see it come into its own.

Proponents insist that SRI is popular because it really increases yields impressively. T.H. Thiyagarajan, dean of the Agricultural College and Research Institute in Killikulam, India, rejects criticisms of individual aspects of SRI. In combination, he says, the whole is greater than the sum of its parts. "The synergistic effect of all these components is the crucial thing." He helped convince the Tamil Nadu state government to spend US$50 000 to promote SRI to local farmers.

In fact, the individual components have been tested in Madagascar and other countries, and each component was found to increase yield. The one that appeared to give the most increase was transplanting younger seedlings. But this practice is more challenging for inexperienced farmers used to handling sturdier older seedlings.

New evidence

Norman Uphoff's weighty response drew attention to new evidence from scientists in China (see "Does SRI work?" this series), Indonesia and India. SRI evaluations were started in Tamil Nadu Agricultural University in India in 2001, and by 2003, it had demonstrated such improvements in yield and profitability that the state government provided $50 000 for spreading SRI practice. About half the rice crop in the Cauvery Delta, the main rice-producing area of Tamil Nadu, will be given over to SRI cultivation; the farmers are so impressed with the size of the harvest and cost savings, including water, over the past two years.

While Sheehy and coworkers reported that SRI crops took 2 weeks longer to mature, that was most likely due to the soil not being well drained and aerated. When properly managed, crops mature more quickly under SRI. In Andhra Pradesh SRI crops matured 10 days earlier, while in Cambodia, they ripened about one week before the conventional crops.

The claim that SRI gave no advantage compared with "best practice" or officially recommended improved cultivation methods is also refuted. In Nepal, farmers compared SRI with their own usual practices and `improved' practice. In 2002, the average SRI yield of 8.07t/ha was 37% higher than the average with improved practices, and 85% higher than the average with farmers' practices.

A. Satyanarayana, rice geneticist responsible for introducing SRI in the Indian state of Andhra Pradesh since the summer season of 2003, responded to Nature's news feature by pointing out that, "The experiences of farmers are quite different from what is reported by sceptical scientists."

More importantly, the costs of SRI are low and its potential productivity very high, which is "more important than ever now that the Green Revolution technologies are showing signs of fatigue."

He gave further evidence that SRI definitely works for Andhra Pradesh farmers and called on scientists to collaborate constructively with farmers (see "Top Indian plant geneticist rebuts SRI critics", this series).


This article can be found on the I-SIS website at http://www.i- sis.org.uk/RiceWars.php
 
If you like this original article from the Institute of Science in Society, and would like to continue receiving articles of this calibre, please consider making a donation or purchase on our website. ISIS is an independent, not-for-profit organisation dedicated to providing critical public information on cutting edge science, and to promoting social accountability and ecological sustainability in science.
 
 
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MATERIAL IN THIS EMAIL MAY BE REPRODUCED IN ANY FORM WITHOUT PERMISSION, ON CONDITION THAT IT IS ACCREDITED ACCORDINGLY AND CONTAINS A LINK TO http://www.i-sis.org.uk/

 
 

The Institute of Science

 in Society

Science Society Sustainability http://www.i-sis.org.uk

General Enquiries sam@i-sis.org.uk Website/Mailing List press-release@i-sis.org.uk ISIS Director m.w.ho@i- sis.org.uk
 

Rice wars

Rice, the staple food crop for more than half the world's population, among them the poorest, is the current target of genetic modification, an activity that has greatly intensified after the rice genome was announced two years ago (see "Rice is life" series, SiS 15, Summer 2002). Since then, all major biotech giants are investing in rice research.

At the same time, a low-input cultivation system that really benefits small farmers worldwide has been spreading, but is dismissed by the scientific establishment as "unscientific". This is one among several recent innovations that increase yields and ward off disease without costly and harmful inputs, all enthusiastically and widely adopted by farmers.

A war is building up between the corporate establishment and the peoples of the world for the possession of rice. The food security of billions is at stake, as is their right to grow the varieties of rice they have created and continue to create, and in the manner they choose.

This extended series will not be appearing all at once, so look out for it.

  • Fantastic Rice Yields Fact or Fallacy?
    • ISIS Press Release 05/07/04

      Top Indian Rice Geneticist

       Rebuts SRI Critics

      Dr. A Satyanarayana responds to criticisms of SRI as someone responsible for introducing the practice to the Andhra Pradesh state of India.

      I read the news feature "Rice cultivation: feast or famine" in Nature (25 March 2004) with great interest as I was responsible for introducing the System of Rice Intensification (SRI) in the Indian state of Andhra Pradesh since the kharif (summer) season of 2003.

      I found the message conveyed by the article not quite balanced. The experiences of farmers are very different from what is said by sceptical scientists. Instead of trying to understand how a rice plant can respond differently under an SRI environment, they are confused about the potential of SRI, giving information based on rice cultivation under flooded conditions that are definitely not SRI practice.

      Having worked as a plant geneticist for over 3 decades on the genetic improvement of leguminous crops under rice-based cropping systems, I have released 34 varieties of various grain legumes that are widely adopted in rice-pulse or rice- rice-pulse cropping systems covering over one million hectares in the state. I have been responsible, from 1995 to 2000, for research in the Krishna and Godavari deltas, which, with 1.5 million ha of rice-growing area, are known as the rice bowl of Andhra Pradesh. At present, I am Director of Extension for the state agricultural university (ANGRAU) and transfer of technology is my job. So, I do know about the rice crop.

      In January 2003, I was able to learn about SRI on a study tour to Sri Lanka, and was amazed to see the potential of this system. On returning to Andhra Pradesh, I started educating farmers on the skills involved in SRI and motivated them to take up this system on a small scale in demonstration plots. We planned to organise 50 demonstrations through ANGRAU's extension service and 150 through the State Department of Agriculture. But more than 300 farmers took up SRI during the summer season of 2003.

      On average, the size of the demonstration plot was 0.4 ha, with the largest at 1.6ha. As many as 10 different varieties, chosen by the farmers themselves, were tried in all 22 districts of the state, under different soil and irrigation systems. The results achieved were highly satisfactory, giving an average yield advantage of over 2.0 t/ha. About 40 farmers got yields over 10t/ha, and 5 districts had average yields over 10t/ha. The highest recorded was 16.2 t/ha followed by 15.7t/ha.

      The average over all the demonstration plots was 8.36t/ha compared to 4.9 t/ha with conventional practice and the state average of 3.89t/ha. These yields are not theoretical. They were properly recorded after thorough drying. On seeing the performance of this system, many farmers volunteered to practice SRI during the current winter season on more than 5 000 acres in the state.

      Many farmers used SRI on over 10 acres. One farmer (Mr. N. V. R. K. Raju) practiced SRI on over 100 acres (40ha.), and an average yield of more than 10 t/ha is expected. I request sceptics to visit Andhra Pradesh and see SRI in practice before drawing conclusions.

      Under SRI, the rice crop is maturing 10 days earlier than with usual cultivation practices, irrespective of the variety, which is contrary to what was stated in the Nature news feature, that SRI takes two weeks longer to mature. Also, SRI required less water and less chemical inputs. SRI gave higher grain as well as straw yield. Moreover, the SRI rice crop has withstood cyclonic gales and a cold spell.

      It is unfortunate to say in the headlines of the news feature that proponents call SRI a "miracle". No one has ever said this because SRI results are quite explainable. Planting young seedlings carefully and at wider spacing gives the plant more time and space for tillering and root growth. Careful water management keeping the field wet and not flooded gives better yield because it supports healthy root growth. This practice should be encouraged everywhere as the whole world is facing water shortages. Weeding rice fields with a rotary weeder helps by churning the soil and incorporating the weed biomass as it aerates the root zone. This encourages the soil microorganisms to proliferate and makes the soil living and healthy. All of these practices are known to agronomists, and there is nothing new or magical.

      The productivity of SRI as a function of input is very high, which is more important now as the Green Revolution technologies are showing fatigue. SRI has the potential to give higher yields at lower costs. Even when the farmers were unable to practice all the aspects the first season, just planting young seedlings carefully at wider spacing with somewhat better water management resulted in over 2.0t/ha extra yield compared to conventional methods using higher inputs. With more experience and mastering of skills, still higher yields are possible, as those obtained by the best farmers clearly suggest.

      Rice yields all over the world have leveled out under the present system of flooded cultivation. Genotype x environment interactions are known to affect the plants' phenotype and performance. We need to be looking for alternatives to the present costly practices with an open mind. SRI is still evolving with the innovations of the farmers making implements and practices more labour-saving.

      There is more than enough evidence accumulated here and elsewhere for scientists to take SRI seriously. I hope that the scientific community will collaborate in further research. Possibly it can refine the technology and reveal the factors responsible for the higher productivity observed. That would be more constructive and more in the spirit of science than dismissing it with limited or faulty data and preconceptions.

      The author is Director of Extension, Acharya N. G. Ranga Agricultural University, Hyderabad-500030, Andhra Pradesh, India, and this article is adapted from his response to the Nature news feature mentioned.


    • This article can be found on the I-SIS website at http://www.i- sis.org.uk/TIRGRSRI.php
       
      If you like this original article from the Institute of Science in Society, and would like to continue receiving articles of this calibre, please consider making a donation or purchase on our website. ISIS is an independent, not-for-profit organisation dedicated to providing critical public information on cutting edge science, and to promoting social accountability and ecological sustainability in science.
       
       
      • If you would prefer to receive future mailings as plain text please let us know.

      The Institute of Science in Society, PO Box 32097, London NW1 OXR
      telephone: [44 20 8643 0681]   [44 20 7383 3376]   [44 20 7272 5636]

      General Enquiries sam@i-sis.org.uk - Website/Mailing List press-release@i-sis.org.uk - ISIS Director m.w.ho@i- sis.org.uk

      MATERIAL IN THIS EMAIL MAY BE REPRODUCED IN ANY FORM WITHOUT PERMISSION, ON CONDITION THAT IT IS ACCREDITED ACCORDINGLY AND CONTAINS A LINK TO http://www.i-sis.org.uk/

       
       

      The Institute of Science

       in Society

      Science Society Sustainability http://www.i-sis.org.uk

      General Enquiries sam@i-sis.org.uk Website/Mailing List press-release@i-sis.org.uk ISIS Director m.w.ho@i- sis.org.uk
       

      Rice wars

      Rice, the staple food crop for more than half the world's population, among them the poorest, is the current target of genetic modification, an activity that has greatly intensified after the rice genome was announced two years ago (see "Rice is life" series, SiS 15, Summer 2002). Since then, all major biotech giants are investing in rice research.

      At the same time, a low-input cultivation system that really benefits small farmers worldwide has been spreading, but is dismissed by the scientific establishment as "unscientific". This is one among several recent innovations that increase yields and ward off disease without costly and harmful inputs, all enthusiastically and widely adopted by farmers.

      A war is building up between the corporate establishment and the peoples of the world for the possession of rice. The food security of billions is at stake, as is their right to grow the varieties of rice they have created and continue to create, and in the manner they choose.

      This extended series will not be appearing all at once, so look out for it.

    • Fantastic Rice Yields Fact or Fallacy?
    • Top Indian Rice Geneticist Rebuts SRI critics
      • ISIS Press Release 06/07/04

        Does SRI Work?

        The first reality check of a low-input rice-growing system took place two years ago and more successes documented since. Dr. Mae-Wan Ho reports

        Sources for this report are available in the ISIS members site. Full details here

        The clearest sign that SRI works, if not miracles, then certainly well enough, is the number of participants drawn to the first in- depth international assessment of it.

        Nearly a hundred people from 18 countries were listed as participants in the 192-page proceedings of the 4-day conference, which took place in Sanya, China, in April 2002. More than three- quarters were scientists, with policy-makers, representatives of non-government organisations, international organisations, private companies and farmers making up the rest. Participants from the host country China made up more than half of the total, and all were scientists from prestigious rice research institutes, agriculture academies or universities.

        The conference was convened, not to assess whether SRI works - for that was the experience of almost everyone who presented papers at the conference - but to assess across nations, "the opportunities and limitations" of a practice that "can give yields about twice the present world average without reliance on new varieties or agrichemicals."

        The conference did bring together a substantial body of evidence from around the world that SRI can increase yield in a variety of soils, climatic conditions, with various local adaptations, and using both indigenous and commercial `high yielding' rice varieties.

        SRI has been "practice- led" thus far, but participants at the conference felt it was time for scientists to catch up and research the knowledge-base, so that a healthy dialectical relationship between practice and knowledge can be achieved to help advance this important project of delivering food security and health to more than half the world's population.

        Since then, more successes have been reported, leaving the scientific establishment even further behind (see "Fantastic rice yields fact or fallacy?" this series).

        Super- yields in Madagascar

        The province of Fianarantsoa, situated in the south-central highlands of Madagascar, now lays claim to the highest yielding rice-fields in the world since the introduction of SRI in the 1990s.

        The highlands are subtropical, with annual rainfall averaging 1375mm. The rainy season occurs during the hot months in the year, where the average temperature rises above 20C. The Fianarantsao region is often affected by cyclones during the rainy season.

        Fianarantsoa attained rice yields of more than 8t/ha in the first year of applying SRI methods, up from the 2t/ha national average. SRI in this region is increasingly linked with the use of compost in rotational cropping with potatoes, beans or other vegetables in the off-season. In the second and succeeding years, the residual and cumulative effects of soil organic matter from composting increased yields still further, to 16t/ha. By the sixth year, yields as high as 20t/ha were measured on farmers' fields in Tsaramandroso, Talatamaty and Soatanana.

        Bruno Andrianaivo, senior agronomist of FOFIFA (National Centre for Applied Research on Rurual Development in Madagascar) emphasized that such high yields cannot be achieved immediately, but requires the cumulative effects of 6 years under SRI.

        However, simply on the conservative figure of 8t/ha yield from SRI practice Andrianaivo estimated a net return to the farmer of 5 million Fmg (about US$770), compared with around 250 000 Fmg (less than US$40) for conventional practice.

        Acceptance in China

        Professor Yuan Longping of China National Hybrid Rice Research and Development Centre played a key role in creating high-yielding super-hybrids throughout the late 1990s and early 2000s by conventional breeding methods. His Centre had already broken all records in boosting rice-hybrid yields when he first heard about SRI from a paper written by Norman Uphoff of Cornell International Institute for Food, Agriculture and Development (see "Fantastic rice yields fact or fallacy?" this series).

        Yuan conducted the first trial of SRI in his Centre's station in Sanya from winter 2000 to spring 2001. Only three varieties yielded above 10t/ha, and SRI gave an average increase of around 10% over the conventional practice. The following year, tests were conducted in the summer at the Centre's station in Changsha. Two varieties yielded 12t/ha, and one 12.9t/ha, a record for the Centre so far. This encouraged more Chinese scientists to conduct SRI research. Of the 8 locations in which his Centre was involved, 5 locations got good results, with yields over 12t/ha.

        Since then, trials by a private sector company, the Meishan Seed Company in Sichuan Province, using a modified SRI method, achieved yields of 15.67/ha and 16t/ha in two different plots, both new records in Sichuan Province (yield in the conventional field was 11.8t/ha).

        Yuan's preliminary evaluation of SRI is enthusiastic: "SRI is a promising way to increase rice yield and to realize the yield potential of any variety.whether high-yielding variety (HYV) or local variety." He confirmed that the method can promote more vigorous growth of rice plants, especially tillers and roots, and noted in addition, less insect and disease problems during the vegetative growth stage, and that there are definite varietal differences in response to SRI practices: those with strong tillering ability and `good plant type' are more favourable for SRI cultivation. "SRI gives higher output with less input, but requires very laborious manual work which makes it more suitable for small farms in developing countries" he said. Moreover, SRI should be modified and adapted to suit local conditions, and as experience teaches.

        For China, he recommended a long list of modifications, including using tray nurseries to raise the young seedlings instead of flooded seedbeds, so as to reduce the trauma of transplanting; and controlling tiller-formation, for although increased tillering gives many more rice-forming panicles, the percentage of productive tillers falls off with the number of tillers, so there is a optimum maximum number.

        He definitely thinks there is scope for combining genetic improvement with SRI methods. For example, breeding plants with a strong ability to form tillers would be appropriate for improving the response to SRI.

        Detailed analyses of the trials were presented in several multi-author research papers. For example, the economic benefits of applying SRI methods were estimated for the hybrid rice Liangyoupei 9, which came both from savings and increased yield. The amount of hybrid seed needed in SRI methods was only 3 - 4.5kg, which represented a seed saving of 8.3 - 10.5kg and nursery saving of 90%, thereby reducing the cost by 215 Yuan/ha. As only compost was applied, the saving on the 10-12t/ha fertilizer that would have been used was 1 200Yuan/ha. The saving on water, some 3 000 tonnes, was about 150 Yuan/ha. The total saving with SRI methods thus amounted to about 1 565 Yuan/ha. Add to that a 15% increase in yield (1.5 tonnes/ha) and the farmer gets a total additional profit of about 3 000 Yuan/ha (about US$ 360).

        The Sichuan Academy of Agricultural Sciences has done SRI trials for three years in succession. Its 2003, trials showed an average SRI yield of 13t/ha. Another series of trials in 7 regions of Zhejian Province using 8 varieties all resulted in increased yield under SRI; the average increase being 1.5t/ha over already high- yielding controls.

        The China National Hybrid Rice Research and Development Centre introduced hybrid varieties into Africa and recommended that they be used with SRI methods. In 2003, a 9.2t/ha yield was obtained with hybrid GY032 in Guinea under SRI methods, which was 4 times the national average yield.

        SRI in Gambia

        The Gambia, a small country (11 700km2) in West African, is a 50 km-wide ribbon of land extending eastward from the coast, bisected by the River Gambia and surrounded on three sides by Senegal. Its annual rainfall is 900 to 1400mm; the rainy season between late May and early October. Rice is the staple of the country and there are 5 very different production systems: upland, lowland rainfed, irrigated (pump and tidal), freshwater swamps and seasonally saline mangrove swamp.

        Annual rice consumption averages 70 to 110kg per capita; domestic production lags behind by 60%, and the balance is met by imports. The national average yield of rice is only 2t/ha.

        SRI was introduced to The Gambia in the rainy season of 2000 as part of the Ph. D. thesis of Mustapha M. Ceesay in Crop and Soil Sciences at Cornell University in the United States. Farmers were invited to visit the first SRI trial site at the Sapu station of the National Agricultural Research Institute (NARI) in The Gambia before they enrolled voluntarily in the research programme.

        During the first year of experimentation, three different plant population densities were investigated with several varieties. Yields ranged from 5.4 to 8.3t/ha. In 2001, plant population densities were investigated alongside fertilizer treatments, and on-farm trials involving 10 farmer households. The on-station SRI trials were conducted under pump irrigation, and on-farm trials under tidal irrigation.

        Plant population densities investigated were 20cm x 20cm, 30cm x 30 cm and 40cm x 40 cm. Two rice varieties were used, and instead of compost, three fertilizer treatment rates were assessed: NKP in the following proportions: 70-30-30 (national recommended), 140- 30-30 and 280-30-30. All trials took place in the lowland.

        The on-station trials indicated that 30cm x 30cm spacing did not decrease yield over the 20cm x 20cm, and was hence recommended to the farmers for the on-farm trial. Fertilizer treatments indicated that under SRI, the nationally recommended lowest rate was as effective as doubling the rate, while tripling the rate gave higher yields, but it was not economically profitable.

        The on-farm trials, conducted in a communal tidal irrigation scheme, gave "exciting" results, "a tripling of yield" on average, 7.4t/ha compared with 2.5t/ha obtained with farmers' current practices. Some farmers experienced more than five-fold increases, from 1.6 to 9.0t/ha in one case, and 1.4 to 8.0t/ha in another.

        But there are problems facing the farmers in land preparation. Farmers in The Gambia still do not have a well- developed culture of water control. Fields are simply kept flooded after transplanting until the rice plants mature, and fertilizer application and weeding are done under submerged conditions. These practices will conflict with the adoption of SRI, but the yield increases may be a sufficient incentive for farmers to overcome these problems.

        SRI in other countries

        Many countries reported remarkable increases in yield. Salinda Dissanayake, Member of Parliament in Sri Lanka, personally tested SRI in his own rice field of a little more than 2 acres for four seasons, using seeds of various varieties. He got the highest yield of 17t/ha with BG358, a variety developed by the Sri Lankan rice researchers. Even with local varieties such as Rathhel and Pachdhaiperumal, usually much lower yielding at ~2t/ha, impressive yields of 8t/ha and 13t/ha were obtained.

        Dissanayake formed a small group to inform farmers of SRI; and farmers who took up SRI from 18 districts have doubled their yields on average.

        "These yields were obtained with less water, less seed, less chemical fertilizer, and less cost of production per kilogram .among SRI users, we find people of many different income and educational levels and different social standing, including many poor farmers having only small plots of land, farmers with moderate income, some agricultural scientists, and a few administrators, businessmen and political leaders who practice it with their own convictions." Dissanayake said.

        H. M. Premaratna, a farmer from the Ecological Farming Centre, Mellawalana, Sri Lanka, backed up the enthusiasm of his Member of Parliament, and has personally provided training on SRI to more than 3 000 farmers by 2002. "From my experience, I have observed that the rice plant becomes a healthier plant once the basic SRI practices are adopted," he said.

        Reports from 17 countries in 2002 showed that three-quarters of the cases gave a significant yield advantage of at least 20 to 50% increase, and although the super-yields reported from Madagascar have not been obtained elsewhere, some farmers in Cambodia and Sri Lanka have come close. Overall, the conventional systems yielded 3.9t/ha, very close to the world average for rice production. The average for all the SRI yields reported was 6.8t/ha.

        A report from the Philippines not only documented yield increases over several successive growing seasons since 1999, but also a reduction of crop pests such as rats and brown and green leafhoppers, carriers of the dreaded rice tungro virus disease. This was attributed to the increased spacing of plants, allowing more sunlight to penetrate even the base of the plant, exposing the hoppers, which detest and avoid sunlight.

        In Cambodia, SRI is spreading very rapidly. Only 28 farmers were willing to try SRI in 2000, by 2003, this number had grown to almost 10 000 and in 2004, 50 000 farmers are expected to adopt it.

        Perhaps the greatest testament that SRI works is the increasing number of farmers that have adopted the practice.


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