This presentation was prepared to assist SRI colleagues in explaining this methodology to others. It can be adapted, translated, shortened, lengthened to meet the needs of various audiences of farmers, extension personnel, policy-makers, and scientists. Some of the latter may find this presentation not detailed enough. There is, to be sure, much more knowledge about SRI generated with the kinds of controls and measurement that scientists expect. This can be provided, from numerous theses and research reports, upon request from email@example.com
This is a basic presentation on SRI, including some pictures that help explain SRI visually. A second section gives some of the scientific evidence that has led to the conclusions presented here, basically that SRI methods enable rice plants to develop into quite different kinds of plants, larger, healthier, more productive -- in scientific language, evoking a different phenotype than has been produced from the same genotype by conventional cultural practices. A second power point presentation provides information and pictures on the practices that achieve the SRI results reported here, with additional sections providing information and pictures on different aspects of SRI.
SRI is about potential – genetic potential that can be evoked with more favorable management practices.
Picture provided by Gamini Batuwitage, at the time Sr. Asst. Secretary of Agriculture, Sri Lanka, of SRI field that yielded 13 t/ha in 2000, the first year SRI was used in that country. Such performance is what got SRI started there.
This picture was provided by Dr. A. Satyanarayana, director of extension for the Indian state of Andhra Pradesh. This picture was taken shortly before harvest. Under usual growing conditions, the variety is productive and favored for its good grain quality, but it does not tiller like this without SRI practices.
Picture provided by Dr. Koma Yang Saing, director, Cambodian Center for the Study and Development of Agriculture (CEDAC), September 2004. We do not know the yield from this field, but it should be at least 3-4 times the national average of 1.8 t/ha.
This field was harvested in March 2004 with representatives from the Department of Agriculture present to measure the yield. They reported a yield of 17 t/ha but this seems so fantastic (given that the average rice yield in Madagascar is 2 t/ha) that we do not want to call attention to it. Picture provided by George Rakotondrabe, staff member with the Landscape Development Interventions project, which has worked with Association Tefy Saina in spreading the use of SRI to reduce land pressures on the remaining rainforest areas.
These two rice plants are ‘twins,’ planted on the same day in the same nursery from the same seed bag. The one on the right was taken out at 9 days and transplanted into an SRI environment. The one on the left was kept in the flooded nursery until its 52 nd day, when it was taken out for transplanting (in Cuba, transplanting of commonly done between 50 and 55 DAP). The difference in root growth and tillering (5 vs. 42) is spectacular. We think this difference is at least in part attributable to the contributions of soil microorganisms producing phytohormones in the rhizosphere that benefit plant growth and performance.
Picture provided by Dr. Rena Perez of SRI field in 2002 at the cooperative where SRI got its start in Cuba. This field gave yields of about 6 t/ha before. This cooperative has expanded from 2 ha to 20 ha in SRI.
Picture provided by Dr. Zhu Defeng, China National Rice Research Institute, September 2004. Dr. Yang Ren Cui, dean of the Fujian College of Agriculture and Forestry, who has been evaluating SRI also in Yunnan Province, reported also a 18 t ha -1 yield there. A professor at Sichuan Agricultural University monitoring SRI trials in Yunnan measured and certified a yield of 20.4 t ha -1 there as probably the highest rice yield yet recorded. I have seen the certificate (in Chinese) but have no picture. (The numbers were legible even if the words were not – a translation was given by Mr. Liu Zhibin, Meishan.)
This is the most succinct statement of what SRI ‘is.’ We emphasize the principles and methods rather than techniques because we regard SRI as a ‘methodology’ rather than as a ‘technology.’ SRI is not a fixed set of practices but rather involves practices that we know can succeed to the extent that they apply, appropriately for the conditions, the principle that constitute SRI.
These bold claims are a starting point for understanding SRI. We say this based on growing experience with SRI methods and results from around the world. In 1999, SRI was known and practiced in only one country in the world, Madagascar, where it was developed. There are at least 21 countries now where the merits of SRI theory and practice have been seen.
SRI has been hard to get accepted because it does not depend on either of the two main strategies of the Green Revolution: it does not require any change in the rice variety used (genotype) since the methods evoke more productive phenotypes from any rice genotype; nor does it require an increase in external inputs -- the latter can in fact be reduced. Water requirements and costs of production can also be reduced. This sounds truly ‘too good to be true,’ but pictures above showed how the plant can become a more vigorous and productive organism, able to acquire more nutrients and sustain larger panicles of rice.
Because we have seen SRI methods succeed so often, and often spectacularly, in a wide variety of conditions, we have confidence that if they are given a fair test, they will prove themselves under most circumstances. Because we are dealing with biological phenomena, one does not get the same results each time or everywhere. In biology, small inputs can yield big outputs – under favorable conditions, with a good environment for growth; or a lot of inputs can produce no output at all – if conditions are unsuitable for sustaining growth. But at least 90% of the time, we have had positive results with these methods, so we are confident in recommending that they be tried.
This is a brief historical background. Fr. de Laulani é came to Madagascar from France in 1961 and spend the next (last) 34 years of his life working with farmers to evolve a system that could address their problems of hunger and poverty, with minimum dependence on external inputs. It took him 20 years of working with farmers to assemble and integrate the practices that now constitute SRI. His only published writing on SRI and its ‘invention’ is his article published in 1993 in the journal Tropicultura (Brussels), Vol. 11, pp. 110-114. “The father of SRI” is a real father. In 1990, with Malagasy friends who were similarly committed to rural development in Madagascar, he established an NGO, Association Tefy Saina , which carried on his work after his death in 1995. CIIFAD joined a USAID-funded project around Ranomafana National Park in 1994 to try to give farmers – practicing shifting agriculture around the Park and encroaching on its endangered forest ecosystems – some good alternatives. Tefy Saina agreed to introduce SRI to any farmers willing to give the new methods a try. The results exceeded CIIFAD expectations, and demonstrated that the claims of Tefy Saina about SRI potential were correct.
Fr. de Laulanie was born in 1920 and got a first degree in agriculture from the agricultural college in Paris that has become Paris-Grignon, the leading French agricultural university. He graduated in 1939 but decided not to pursue agriculture, given the changes in his and others’ lived caused by the outbreak of World War II, and entered a Jesuit seminar in 1941 to make his life one of service, graduating in 1945. In 1961, as noted on the previous slide, he was sent by the Jesuit order to Madagascar, where decided that he could probably make his greatest contribution to others’ welfare by helping to improve rice productivity.
Rafaralahy and Rabendrasana began working with Fr. de Laulanie in the mid-1980s while they were directing the government’s handicraft (artisanat) agency and assisted him with the school for young farmers that he had established in Antsirabe. In 1990, after it became clear that the government was not going to give any assistance or boost to SRI, Sebastien and Justin and some other friends joined Fr. de Laulanie in forming Tefy Saina, resigning their government jobs to bring the benefits of SRI to their fellow Malagasys. In 2003, Sebastien and Justin received the award for Slow Food Movements’ award for Environmental Protection at an award ceremony in Naples, Italy.
We want to emphasize that SRI is ‘not finished’ – but is only just starting. We welcome the inputs and the improvements of farmers, scientists, lay persons, anyone who works with SRI empirically and with an interest in developing explanations and better applications.
There are, as is to be expected, some costs or uncertainties associated with SRI, but these are surprisingly few, and most can be mitigated or have some offsetting benefits. The claim that SRI is more risky has been shown to be incorrect in Cambodia and Sri Lanka by independent evaluations done for GTZ and for IWMI, respectively.
SRI defies usual logic – that it takes more input to get more outputs. But our proposition that “less” can produce “more,” for a number of different but reinforcing reasons, can be well supported from the scientific literature.
This section is more technical than may be of interest to most farmers, but if there is time, they should be shown the kind of analysis that rice scientists do. Some farmers may become interested in acquainting themselves more with such research, its methods and its conclusions.
As noted already, CIIFAD waited for three years of results before trying to get SRI evaluated outside of Madagascar. Skepticism is understandable. But 90% of the time that the methods are used as recommended, there are yield increases of at least 25%, but more often they are 50-100%, and a number of times there have been 200-300% increases. SRI experience is requiring a reevaluation of current scientific thinking about SRI. Many scientists have welcomes this opportunity to expand knowledge and improve practice. Some have resisted SRI, dismissing it as “voodoo science” (Cassman and Sinclair, ACCSA, March 2004), or claiming (on the basis of one set of on-station trials, that did not follow a recommended protocol for SRI) that SRI will make no general improvement in rice production (Sheehy et al., Field Crops Research, 2004). This conclusion is contradicted by the evaluation research of dozens of rice scientists at leading institutions in China, India and Indonesia. SRI is now entering a period when the scientific knowledge base is expanding rapidly. The following short summaries report research results that helped us get an understanding of what is happening in the rice plant when SRI methods are used. We know less about what is happening in and around the rice plant roots, and in particular about the contribution that soil microbes (aerobic bacteria and fungi) may be making in the rhizosphere by producing phytohormones (auxins, cytokinins, etc.) that stimulate root growth, as seen in the slide above comparing rice plants from Cuba, same variety, same age, started in the same nursery. But the SRI plant was taken out at 9 days of age and transplanted into an SRI growing environment – where we think the plant growth was accelerated by microbial biochemical stimulation. This, however, remains to be investigated systematically.
This is explained more on the next slide.
This figure shows research findings from the China National Rice Research Institute (CNRRI), published in the proceedings of the first international SRI conference, held at Sanya, China, in April 2002. Two different rice varieties were used with SRI and conventional (CK) methods. The second variety responded more positively to the new methods than did the first in terms of leaf area and dry matter as measured at different elevations. But both varieties had more leaf area and dry matter when grown with SRI methods than with conventional methods.
This is explained more on next two slides.
Figure from Sichuan Academy of Agricultural Sciences research on SRI, comparing the leaf area of SRI rice plants with conventional rice plants, with same variety and otherwise the same growing conditions.
Graph showing results from research on SRI done by the Sichuan Academy of Agricultural Sciences. Same findings (except less dr matter in panicle) were found at the full heading stage.
This is explained more on the next slide.
This figure from a report made by Nanjing Agricultural University researchers to the Sanya conference in 2002, and reproduced from those proceedings, shows that the oxygenation ability of rice roots growing under SRI conditions are about double the ability, throughout the growth cycle, compared to the same variety grown under conventional conditions. At maturity, the SRI roots have still almost 3x the oxygenation ability of conventionally grown rice plants.
This evaluation is explained on the next slide.
Figures from a paper presented by Dr. Tao to international rice conference organized by the China National Rice Research Institute for the International Year of Rice and World Food Day, held in Hangzhou, October 15-17, 2004. Dr. Tao has been doing research on SRI since 2001 to evaluate its effects in physiological terms.
Barison did his undergraduate thesis for a baccalaureate degree at the University of Antananarivo in 1998 with an extensive evaluation of SRI methods, with 171 trial plots laid out on farmers’ fields around Ranomafana, varying age of seedling, spacing, number of plants per hill, etc. The most dramatic finding was difference in root pulling resistance, a measure of root development introduced by IRRI in the early 1980s. Subsequently for his M.S. thesis in Crop and Soil Sciences at Cornell University, Barison did more detailed evaluation of SRI in terms of crop physiology, crop physical features, and yield.
Barison did on-station trials at Beforona in Madagascar to compare many parameters of SRI vs. conventional rice plants. This shows the differences in root length density at different depths with different management practices. SRA stands for System de Riziculture Amelioree, system of rice improvement, promoted by government researchers using fertilizer, row planting, etc. – the ‘modern’ package in contrast with farmer practice.
Farmers in India who have become acquainted with and enthusiastic about SRI are now inspecting their plant roots, having seen what a huge difference is possible. The farmer who was the first to use IR-8 variety back in the 1960s, N. Subba Rao, pointed out the difference in a demonstration of SRI and conventional plants that he set up on the veranda of his home in Achanta, Andhra Pradesh, India, agreeing that SRI could be properly designated as “the root revolution.”
Picture provided by Dr. P. V. Satyanarayana, the plant breeder at Maruteru agricultural research station who developed this variety which was already very popular with farmers before it was found to respond very well to SRI management practices.
In Cuba, rice plants are commonly transplanted very late (too late), at 50-55 days. So SRI is quite a radical departure. The farmer whose plants these are (Luis Romero) was one of the first in Cuba to try SRI and he is now working closely with the Cuban Institute for Rice Research (IAA), located about 10 miles from his farm. We think that his soil must be very rich in soil microbes that are particularly response to SRI practices (soil aeration and addition of organic matter).
Joeli Barison did a Master’s degree in Crop and Soil Sciences at Cornell University, 1999-2002, with field research on SRI done in Madagascar, both on-station analyses at the Center for Diffusion of Intensified Agriculture at Beforona, and field studies in four areas of Madagascar where farmers could be identified who were using both SRI methods and conventional methods. These farmers’ conventional yields were about 50% more than the Madagascar average, so they were already using some modern methods.
In on-farm research, Barison analyzed the rice plants on 108 farms where farmers were using both SRI and conventional growing methods, so that there would be minimal influence of inter-farm or inter-farmer differences. Same varieties and same soils. The QUEFTS modeling exercise is quite standard in plant evaluation. The SRI plants had a very different capacity to take up N (and P and K) and to convert them into grain.
These data were reported by Prof. Robert Randriamiharisoa, head of the Agriculture Department at the University of Antananarivo, to the SRI conference held in Sanya, China, in 2002. They give the first direct evidence of the contribution that soil microbes make to the high yields achieved with SRI methods. The bacterium Azospirillum was studied as an ‘indicator species’ presumably reflecting overall levels of microbial populations and activity in and around the plant roots. It was an organism that could be reliably studied and counted with laboratory facilities in Madagascar. Somewhat surprisingly, there was no significant difference in Azospirillum populations in the rhizosphere (the soil around the roots). But there were huge differences in the counts of Azospirillum in the roots themselves according to soil types (clay vs. loam) and cultivation practices (traditional vs. SRI) and nutrient amendments (none vs. NPK vs. compost). NPK amendments with SRI produced very good results, on clay soil a yield five times higher than traditional methods and no amendments. But compost used with SRI gives a yield six times higher. NPK decreases Azospirillum (and other) microbial populations, so most/much of the N that produced the 9 t/ha yield was coming from inorganic sources. The higher 10.5 t/ha yield obtained with compost depended entirely on organic N. Organic methods were capable of producing a tripling of yield on loam soil and a quintupling on clay soil. These kinds of evaluations will give somewhat different numbers according to soil quality, variety used, etc., but the overall relationship seen here should be quite robust. On poorer soil, SRI methods do not have much effect, but when enriched with compost, even this poor soil can give a huge increase in production, attributable to the largest of the increases in microbial activity in the roots. At least, this is how we interpret these findings. Similar research should be repeated many times, with different soils, varieties and climates. We consider these findings significant because they mirror results we have seen in other carefully measured SRI results in Madagascar. Tragically, Prof. Randriamiharisoa, who initiated this work, passed away in August, 2004, so we will no longer have his acute intelligence and probing mind to advance these frontiers of knowledge.
Modern scientific investigation emphasizes precision of measurement and replication of results. The interaction of many factors in SRI makes both difficult and complicates the construction and verification of explanations. But this does not negate the results. With SRI, we look for patterns and trends, accepting that there will be variation in results from place to place and from time to time. Scientists who have taken an interest in SRI are mostly also very interested in knowing farmer experience and ideas, so it has opened up some promising new patterns of researcher-user collaboration. We think that SRI concepts and practices are going to be useful for improving other crop production. Already there is initial confirmation of this for wheat and sorghum.
0425 The System of Rice Intensification (SRI): An Overview - Part I
The System of Rice Intensification (SRI): An Overview Cornell International Institute for Food, Agriculture and Development (CIIFAD) and Association Tefy Saina, Madagascar
Rice Plants Have More Potential than Has Been Realized Previously <ul><li>The System of Rice Intensification (SRI) is a methodology -- not a technology-- for bringing out this potential in rice plants </li></ul><ul><li>It does not depend on purchased inputs -- fertilizer, agrochemicals – saving money </li></ul><ul><li>It does require more labor initially (while learning the methods) and more attention to management , with careful water control </li></ul><ul><li>However, it can become labor saving – saving also water and seed, and reducing risk </li></ul><ul><li>Better grain quality ; higher milling outturn </li></ul>
An SRI field in Sri Lanka, 2002 – 13 t/ha yield
A single rice plant grown with SRI methods from modern variety (MTU 7029) in Andhra Pradesh, India, 2003-04; usual average yield = 6.55 t/ha; with SRI = 10.20 t/ha
Cambodian rice farmer with plant grown from a single seed, using traditional variety and SRI methods
Two rice plants in Cuba: same variety (VN 2084) and same age (52 days); 42 tillers on SRI plant vs. 5 tillers on the other
Cuba -- CPA Camilo Cienfuegos cooperative -- 14 t/ha
SRI field in Yunnan, China, hybrid variety, 2004 – 18 t/ha
The Basic Ideas of SRI A set of principles and methods that help farmers get more productive rice plants from ANY VARIETY of rice ( i.e., getting better phenotypes from any genotype ) SRI methods accomplish this improvement by making changes in the management of plants, soil, water, and nutrients to (a) induce greater ROOT GROWTH , and (b) nurture more abundant and diverse populations of SOIL ORGANISMS
For Centuries, Even Millennia: <ul><li>We have FLOODED rice plants, drowning their roots and causing roots to degenerate </li></ul><ul><li>We have CROWDED plants, constraining growth potential of their shoots and roots </li></ul><ul><li>We now apply FERTILIZERS and AGRO-CHEMICALS that affect the life in the soil </li></ul><ul><li>Soil organisms provide many services: N fixation, P solubilization, protection against diseases and climate stresses, etc. </li></ul><ul><li>Usual rice practices interfere with these benefits </li></ul>
Compare Two Different Strategies: <ul><li>The GREEN REVOLUTION strategy: </li></ul><ul><li>(a) Changed the genetic potential of plants, and </li></ul><ul><li>(b) Increased the use of external inputs – requiring more water, fertilizer, pesticides, etc. </li></ul><ul><li>This succeeded, but at a fairly high (growing) cost </li></ul><ul><li>SRI strategy does neither -- instead it changes how rice plants, soil, water and nutrients are managed </li></ul><ul><ul><li>This reduces water requirements and costs of production , </li></ul></ul><ul><ul><li>It also raises the productivity of land, labor, water and capital , so that SRI can raise farmer incomes even more than yield </li></ul></ul><ul><li>SRI benefits come from (a) having larger root systems , and (b) greater abundance and diversity of bacteria, fungi, earthworms and other organisms in the soil </li></ul>
SRI Sounds ‘Too Good to be True’ – But It Is True <ul><li>Until 1999, SRI was known in only one country (Madagascar) </li></ul><ul><li>In last 5 years, SRI effects have been demonstrated in 20 more countries: </li></ul><ul><ul><li>Bangladesh, Cambodia, China, India, Indonesia, Laos, Myanmar, Nepal, Philippines, Sri Lanka, Thailand, Vietnam </li></ul></ul><ul><ul><li>Benin, Gambia, Guinea, Mozambique, Senegal, Sierra Leone </li></ul></ul><ul><ul><li>Cuba, Peru </li></ul></ul>
The System of Rice Intensification <ul><li>Was evolved in Madagascar over 20 yrs by Fr. Henri de Laulanié, S.J. – working with farmers, observing, experimenting, also having some luck in 1983-84 season </li></ul><ul><li>Association Tefy Saina was set up in 1990 by Fr. de Laulanie with friends to promote SRI and rural development in Madagascar </li></ul><ul><li>CIIFAD began working with Tefy Saina in 1994; CIIFAD did not accept SRI until 1997 after farmers who had been getting 2 t/ha averaged 8 t/ha for three years with SRI </li></ul>
Fr. de Laulani é not long before he died in 1995
Sebastien Rafaralahy and Justin Rabenandrasana, president and secretary of Association Tefy Saina
Spread of SRI Has Been Rapid <ul><li>First demonstrations of SRI were in 1999: </li></ul><ul><ul><li>Nanjing Agricultural University in China </li></ul></ul><ul><ul><li>Indonesian Rice Research Institute at Sukamandi </li></ul></ul><ul><li>Since then: NGOs, universities, farmer organizations, govt. research institutes and others have taken an interest in SRI -- testing it, evaluating it, and disseminating it </li></ul><ul><li>Also improving on it, adapting it to local conditions – SRI is a “work in progress” </li></ul><ul><li>Farmer innovation is encouraged </li></ul><ul><li>Leading research institutions in China, India and Indonesia have accepted SRI based on their years of evaluation </li></ul>
What Are the Negatives? <ul><li>Labor requirements are initially increased (25-50%) but with experience, SRI can become: </li></ul><ul><ul><li>labor-neutral (GTZ evaluation in Cambodia) or </li></ul></ul><ul><ul><li>labor-saving (CAU in China; TNAU in India) </li></ul></ul><ul><li>Water control is necessary for best results, but can be done thru investment & organization </li></ul><ul><li>Farmer learning is a benefit as well as a cost </li></ul><ul><li>Disadoption? – only reported in Madagascar </li></ul><ul><li>Nematodes? – problem in Thailand, elsewhere? </li></ul><ul><li>No claim that SRI will be successful everywhere </li></ul>
SRI goes against usual logic: LESS CAN PRODUCE MORE <ul><li>By utilizing biological potentials & processes </li></ul><ul><li>Smaller, younger seedlings become larger, more productive mature plants </li></ul><ul><li>Fewer plants per hill and per m 2 can give higher yield if used with other SRI practices </li></ul><ul><li>Half as much water produces more rice because aerobic soil conditions are better </li></ul><ul><li>Fewer or even no purchased inputs can make greater output possible, because soil organisms increase and are more active </li></ul><ul><li>Lliving soil is the key to SRI performance </li></ul>
Initial Skepticism Was Warranted <ul><li>SRI results are remarkable, sometimes beyond what has been considered as the ‘biological maximum’ for rice </li></ul><ul><li>But growing body of research evidence, especially from China, documents that SRI practices induce physiological changes in rice plants that make them more productive; SRI is no magic -- all is can be explained in scientific terms </li></ul>
Study by China National Rice Research Institute , Hangzhou <ul><li>Comparison of SRI vs. standard methods (CK = check or control) with 2 different varieties of rice </li></ul><ul><li>Measuring leaf area and dry matter at different levels of the shoot (plant above ground) </li></ul><ul><li>Both varieties respond positively to SRI methods: Liangyoupeijiu responds more </li></ul>
Plant Physical Structure and Light Intensity Distribution at Heading Stage (Tao et al., CNRRI, 2002)
Evaluations Done by Sichuan Academy of Agricultural Sciences in China <ul><li>Measurements were made compare the same variety of rice growth with SRI or with conventional (CK) methods </li></ul><ul><li>The leaf area index (LAI) was measured at different stages during growth cycle </li></ul><ul><li>Dry matter accumulation in different plant organs was measured at different stages – the results are shown here for the rice plant at maturity </li></ul>
Figure 1. Change of leaf area index (LAI) during growth cycle (Zheng et al., 2003)
Dry Matter Accumulation between SRI and Control (CK) Practices (kg/ha) at Maturity (Zheng et al., SAAS, 2003)
Researchers at Nanjing Agricultural University in China Studied Roots <ul><li>Using the same variety (Wuxianggeng 9), rice plants were grown with SRI (S) and usual methods (W) under controlled conditions </li></ul><ul><li>At different growth stages -- effective tillering, jointing, heading, and maturity -- a chemical compound ( ά -naphthylamide) was measured in the roots to assess their oxygenation ability </li></ul><ul><li>Throughout the growth cycle, his compound was 2-3 times higher in the SRI plant roots, reflecting greater SRI root activity </li></ul>
Root Oxygenation Ability with SRI vs. Conventionally-Grown Rice Research done at Nanjing Agricultural University, Wuxianggeng 9 variety (Wang et al. 2002)
Researchers at the China National Rice Research Institute Assessed the Dry Matter in Different Plant Organs <ul><li>The dry weight of above-ground organs was compared at different growth stages: </li></ul><ul><ul><li>Stem </li></ul></ul><ul><ul><li>Sheath </li></ul></ul><ul><ul><li>Leaf </li></ul></ul><ul><ul><li>Panicle (grain ear) </li></ul></ul><ul><ul><li>Senescent leaf and sheath (shown in yellow) </li></ul></ul><ul><li>The differences in phenotype seen in pictures can be shown in graphic form: </li></ul>
47.9% 34.7% Non-Flooding Rice Farming Technology in Irrigated Paddy Field, Dr. Tao Longxing, China National Rice Research Institute, 2004
Root Research in Madagascar <ul><li>Research by Barison (1998) found that it took 28 kg of force to pull up clump of 3 rice plants conventionally grown, on average </li></ul><ul><li>Single SRI plants , however, required 53 kg each -- >5 times more force per plant </li></ul><ul><li>Research in 2001 measured root length density (cm of roots per cm 3 ) at different depths in soil, comparing (1) SRI methods with and without compost; (2) improved methods (SRA) with and without fertilizer; and (3) conventional practice </li></ul><ul><li>At 30-50 cm depth, SRI roots were twice as much </li></ul>
Table 13: Root Length Density (cm/cm 3 ) under SRI, ‘Modern’ (SRA) and Conventional Practices (Barison, 2002) Results from replicated on-station trials Treatments Soil layers (cm) 0-5 5-10 10-20 20-30 30-40 40-50 SRI -- with compost 3.65 0.75 0.61 0.33 0.30 0.23 SRI -- without compost 3.33 0.71 0.57 0.32 0.25 0.20 SRA with NPK and urea 3.73 0.99 0.65 0.34 0.18 0.09 SRA without fertilization 3.24 0.85 0.55 0.31 0.15 0.07 Conventional practice 4.11 1.28 1.19 0.36 0.13 0.06
These differences are easy to see <ul><li>Farmers, extension personnel and researchers should all get in the habit of examining roots – this is seldom done! </li></ul><ul><li>Size of root system, length of roots, and their color should be inspected – white color indicates healthy roots, not black color and dying back for lack of oxygen </li></ul><ul><li>Next slide shows the kind of root growth that is possible with SRI methods </li></ul>
Roots of a single rice plant (MTU 1071) grown at Agricultural Research Station Maruteru, AP, India, 2003 season
Two plants on left were started in same nursery as plant on right, but were transplanted into SRI conditions at 9 days. They are the same variety (VN 2084) and same age (80 days) Plants from farm of Luis Romero, San Antonio de los Ba ñ os, Cuba
Modeling Analysis of Yield Response to Nutrient Uptake <ul><li>Barison used QUEFTS model to analyze rice plants and yield with SRI or usual methods on 108 farms in Madagascar where farmers used both methods – to have both farms and farmers the same </li></ul><ul><li>The efficiency of plants is very different as SRI plants give about twice as much grain for uptake of N (also P and K) </li></ul>
Figure 8: Linear regression relationship between N uptake and grain yield for SRI and conventional methods, using QUEFTS modeling methodology (Barison, 2002) Results are from on-farm comparisons (N = 108)
Changes within the Roots <ul><li>This research is just beginning, but a study in 2002 showed dramatic changes in the populations of a nitrogen-fixing bacteria ( Azospirillum ) in rice roots in response to SRI changes in plant, soil, water and nutrient management </li></ul><ul><li>These were associated with large change in yield : from 1.8 t/ha with conventional methods to 10.5 t/ha with all-SRI practice (results are averages for 6 replications) </li></ul><ul><li>Fertilizer gave good results; but compost gave even better results </li></ul>
Analysis of Effects on Plant <ul><li>Dr. T. M. Thiyagarajan, Tamil Nadu Agricultural University, did analyses of SRI and conventionally-grown plants at TNAU experimental farm during 2001-2002 cropping year </li></ul><ul><ul><li>Variety CORH-2 (125 d) in wet season, </li></ul></ul><ul><ul><li>Variety ADTRH-1 (115 d) in dry season </li></ul></ul><ul><li>With the following results showing strong differences in different aspects of plant physiology </li></ul>
Effects of SRI on crop physiology Wet Season (2001-02) Dry Season (2002) Conventional SRI Conventional SRI Total chlorophyll (mg g -1 ) 2.76 3.20 2.60 3.13 Soluble protein (mg g -1 ) 8.35 12.62 10.25 11.95 Nitrate reductase (mg NO 2 g -1 h -1 ) 12.42 18.11 11.74 16.70 Root CEC (mg 100g -1 ) - - 8.40 11.23 Cytokinins (pmol g -1 ) - - 56.77 72.47
Scientific Studies Are Increasing <ul><li>Numbers (totals, averages, rates, etc.) will vary for different soils, varieties, climatic conditions, water mgmt, etc. </li></ul><ul><li>SRI depends on biological processes , which means that results can vary widely depending upon the growing conditions </li></ul><ul><li>Challenge is to explain remarkable results </li></ul><ul><li>The results are real and often repeated </li></ul><ul><li>Farmers, scientists and extension staff should work together to be better able to advance knowledge and practice </li></ul>
THANK YOU Email: [email_address] or [email_address] Web page: http://ciifad.cornell.edu/sri/