Research Note

Every farmer needs to be an experimenter when it comes to SRI since there is  no standard SRI package of practices universal to all regions. At SriAg Farms during Kharif 2010, Paddy was cultivated under SRI method in 10 acres under different treatments – SRI 25×25 cm spacing, SRI 25×12.5 cm spacing,  SRI Biofertilizers, SRI Chemical fertilizers, SRI Heavy soil and SRI Light soil. Paddy was also cultivated under traditional method in 3 acres to draw meaningful comparisons between SRI and traditional methods. All treatments were providied with uniform chemical fertilizer dosage except in fields where biofertilizers were applied. All trials were conducted in SriAg Farms fields under the supervision of DAATTC Scientists.


To cultivate paddy under SRI method under different spacings and fertilizers in order to develop a package that sustainably produces highest yields at lowest cost.

Materials and Methods: 

Transplanting of 10-14 day old seedlings, two (2 )seedlings/hill was performed during  the second fortnight of June 2010 and the crop was harvested during the first fortnight of December 2010. Two seedlings/hill were planted instead of single seedling/hill to control weed population and to account for seedling mortality. Alternate wetting and drying irrigation was provided in  SRI fields and flood  irrigation was provided  in traditional fields. Approximately 5 tons/ac FYM was applied prior to field preparation.

Uniform dosage of chemical fertilizers were applied (per zonal recommendation) in all SRI and traditional fields except in the fields where biofertilizers were applied. Biofertilizers were obtained from Prathista Industries  and chemical fertilizers were obtained from local vendors. We followed Prathista Industries recommended dosage for biofertilizers. The soil types in the fields selected ranged from heavy soils (clay loams) to light soils (sandy loams).


Yield attribute data was collected in all the replicates and the average results are presented in the table and graphs below:

SRI Paddy Trails Yield Attributes Data

SRI Paddy Tillers Data

SRI Paddy Panicles Per Plant

SRI Paddy Panicle length

SRI Paddy Productive tillers per square meter


SRI Paddy yield

SRI Paddy Yields, Janisha Farms

Dr. B C Barah says:

Dec 26, 2010




admin says:

Dec 27, 2010

Thank you Dr. Barah for your comments. It is indeed the number of productive tillers and plant population that played a key role in our first year SRI trials. Yes this is farmers data under the supervision of scientists.

Dr Amod Thakur says:

Dec 28, 2010

There is no reason that in 25×25 cm spacing the % of productive tillers will reduce so much (37%), as you can also observe that in another treatments of similar spacing, the productive tillers were higher. Either the data collected is not properly done or may be another factors like disease or nutrient difficiency or some other factor may be responsible. So i request you to try it for another season. Regarding plant population in 25 x12.5 cm spacing it should be 32 instead of 28. I also request you to try 20×20 cm in future, as in many cases it gives highest grain yield (not 25×12.5). Square planting is always advantageous, as it gives roots/plants to spread all around and operation of weeder will also easier. Planting of 2 seedlinds for lesser weed problem, doesn’t make any sense, however, your second point regarding seedling mortality is valid one. As far as yield is concerned there will not be any changes whether you plant 1 or 2 seedlings/hill, but you have to ensure the maintenance of plant population.
I will be happy to share any information, if you want.

admin says:

Dec 31, 2010

Thank you Dr. Amod for your comments. The % productive tillers in SRI is not significantly different from traditional which is contrary to what I expected. All the data was collected in replicates and was averaged. The data was collected properly by our farm managers under the supervision of scientists. We did not observe more disease incidence in Heavysoil SRI 25×25 cm compared to other treatments. Nutrient deficiency could be factor, however we applied recommended dosage to all treatments. Does heavy soil SRI 25×25 need more nutrients?

25×12.5 cm is one side 4 plants and the other side 7 plants so it is 28 plants. we added three more plants between the four plants on side thus making a total of 7 plants.

We will definitely try 20×20 cm next year in an acre to compare the yield with 25×12.5 cm. 25×12.5 cm spacing consistently produced high yeilds in trials conducted by DAATC scientists for more than 3 years. Do you think we can get more than 10 tons/ha if we go for 20×20 cm spacing?

We could perform mechanical and manual cono weeding in only one direction in all the treatments, so 25×12.5 cm spacing did not pose a problem to us in terms of weeding. Spreading the roots around is a valid point.

Are there studies showing that 1 or 2 seedlings/hill does not make a difference? Is it the same case with 3 seedlings/hill? This is a very critical point since we are going for mechanical transplantation from next season onwards and the machine an do 2 or 4 or 6 or 8 seedlings/hill.

Your insight into our data is really appreciated!

M S Vani says:

Jan 5, 2011

Thanks to Janisha Farms for sharing data. There are many issues to be discussed – i will refer to only one point. in our SRI Initiaitve in Baghpat District Uttar Pradesh, we also found that the difference in percentage of productive tillers between SRI and non-SRI was not significant- just one percentage point higher in the former.

has Janisha farms conducted soil tests? what is the quality of these tests? do fields in same location show significant differences in soil quality? in our SRI report posted on sriindia group email site, we have included some information on soil tests.

best wishes

New Delhi

Dr. Norman Uphoff says:

Jan 18, 2011

The report from Reddy is very interesting, and the kind of analytical experimentation and comparison that is always to be encouraged. As he correctly says, SRI farmers should be experimenters, because their task is to optimize the use and productivity of all the available resources. Crop productivity is a multi-dimensional phenomenon, with unanticipated and/or non-linear interactions. These need to be assessed empirically, under realistic field conditions.

Let me share some general thoughts, based on observations from others’ use of SRI methods, not based on any knowledge of Reddy Ganta’s particular set of conditions. If he finds that two plants per hill are more productive than one plant per hill, this suggest to me that his soil may not be very well-endowed with soil organisms. In Madagascar, I have seen that the highest yields have come from single rice plants very widely spaced, as much as 50×50 cm, but after several years of organic soil management. Such results do not come in the first year of SRI practice. The best crop performances come after 5-10 years of continuous organic soil management and enrichment, achieving a high level of soil biodiversity.

I have no direct evidence on this, but I am piecing this explanation together from reading and some small studies. Especially if soils have been previously managed with inorganic nutrients, there can be an unbalancing or depressing effect on the soil biota. This can be remedied but only with organic inputs applied over some period of time, to build up high soil fertility, which I assign to the abundance and diversity of soil organisms. Fertile soil is living soil; conversely, we all know that ‘dead soil’ is infertile. It isn’t the exhaustion of chemical elements so much as the loss of life, due to desiccation, compaction, loss of organic carbon and other energy sources for soil organisms.

If there is enough addition of organic matter to the soil, this can support very high off-takes of grain and straw for years and years – provided that the straw and/or other biomass will be returned to the soil. Possibly there can develop some particularly micronutrient shortages, which it would pay to remedy, e.g., zinc. Some SRI farmers report that zinc sulphate boosts yield. SRI is not necessarily ‘organic’ in the sense of making no chemical amendments to the soil. If there are soil deficiencies, and micronutrient deficiencies are always possible, these can and should be remedied. What SRI does NOT support is trying to drive up yields by ‘forced feeding’ of the plants, giving an excess of supply of nutrients (esp. N) more than the plants’ own natural demand.

Sufficient N should be made available by biological processes in well-managed soil systems. K is usually relatively abundant, so soil with good structure (aggregation and porosity) and lots of ‘life’ in it should not have this deficiency; and the same applies for phosphorus, as most soils will have 10, 20, 30 times more ‘unavailable P’ in them than is ‘available’ (in the soil solution) at any one time. The activity of soil organisms (phosphate-solubilizing bacteria) will transfer P from the unavailable pool to the available pool. But the key to all this is promoting the abundance and diversity of soil organisms. I would thus be cautious about drawing any firm conclusions from the first-year results reported by Mr. Reddy Ganta. I would like to see what the relationships are after 3 or 4 years. To be sure, we should look at each year’s results – I value and consider any systematic data that I can get from any reliable source — but to make interim assessments.

On the matter of converting tiller number into effective panicles: this is an area where I don’t think crop scientists have yet any very good explanation. As Dr. Barah points out in his response, it is total number of effective tillers per m2 — plus grains/panicle and grain weight — that accounts for yield. If the plant produces a lot of ineffective tillers, but these get returned to the soil, while one can harvest a larger number of total panicles (and more and heavier grains) on an area basis, this is good for the farmer and good for the cattle and/or soil.

I think that the more we go toward fully organic soil fertilization and maintenance, the higher will be the percentage of effective tillers. In an evaluation of rainfed SRI in the southern Philippines, using a popular local variety and fully organic fertilization plus foliar seaweed spray, it was found that effective tillering was as high as 99% with wide spacing (http://ciifad.cornell.edu/sri/countries/philippines/binuprst.pdf) In China, on the other hand, where SRI colleagues still have great faith and reliance on inorganic fertilizer, esp. N, their effective tillering rate is often as low as 50%. The find that SRI methods are giving higher yield but not as much higher as I would expect. So far, I haven’t been able to persuade them to focus on producing and applying organic matter for their rice paddies. Indian colleagues should do their own experimentation and evaluation on this relationship. Let me propose a simple (and falsifiable) hypothesis: that the percent of effective tillers will increase in response to an increase in organic fertilization.

This does not mean that SRI should be only or always organic. While there are many merits in this, many farmers face a variety of constraints in terms of labor availability, biomass availability, etc. So promotion of organic agricultural production is something to be approached non-dogmatically. There has been many times less research and experimentation on how to produce, process and apply biomass in its various forms to enhance the structure and functioning of soil systems — compared to the huge amount of resources that have gone into developing and promoting inorganic fertilization. Large commercial interests have a stake in continuing India’s dependence on their products. They benefit from large government subsidies, but as important, they have the support of public opinion, which attributes almost miraculous powers to fertilizers. Journalists reinforce this message. Politicians make a big deal out of distributing fertilizer. Teachers teach the need for chemical replacement of soil nutrients. Etc. etc. Simply exalting ‘organic agriculture’ is not going to change thinking. We need to have more and more systematic evidence.

Very few policy makers can yet imagine the organic alternative being practiced effectively and economically on a large scale. Most farmers also have accepted the verdict that: ‘organic agriculture cannot feed India (or the world)’ so they don’t even contemplate that avenue. Fortunately, this conventional wisdom is changing within the farming community. To shift opinion and practice, however, there will need to be much innovation (a) in the mobilization and use of organic materials for the soil, (b) in the tools and implements for this (cutters, shredders, digesters, wheelbarrows and wagons, etc.) to make labor much more efficient now with often-antiquated equipment, (c) in knowing what plants, within farming system and within landscapes, can give most benefit, and (d) in policies, to shift subsidization from inorganic to organic soil amendments, to reward healthy food in the marketplace rather than junk food or other food that has less nutritional value than it could and should have.

As important, farmers and researchers should be looking at the effects of ‘healthier soil’ with rich organic endowments on crops’ resistance (a) to pests and diseases and (b) to the adverse effects of climate change (drought, heat, storms, flooding, cold snaps, etc.). There should be very thorough and rigorous evaluation of how SRI and more-organic crop management can reduce crops’ vulnerability to adverse weather conditions. As important, there should be systematic evaluations on the effects of such management on crops’ vulnerability to pest and disease losses.

A book, now available in paperback from Amazon, by a French agricultural scientist, Francis Chaboussou, HEALTHY CROPS (Jon Anderson Press, Charnley, UK, 2004 – first published, in French, in 1985), should be widely read and should become a best seller in India (and elsewhere). Maybe WASSAN or some other organization can get copyright permission to publish an inexpensive Indian edition. I am sure that the holders of copyright, the Gaia Foundation in the UK, would welcome this. These kinds of management strategies are going to be necessary, I think, for Indian (and other) agricultural sectors and practitioners to succeed in the decades ahead.

But this goes far beyond the queries raised by Mr. Reddy Ganta. His experimentation and reporting are very welcome, and I salute his efforts. Such analytical encounters with ‘the real world’ are a source of continuous challenge to our present thinking and practice. Happy New Year!
Norman (Uphoff)

admin says:

Jan 18, 2011

Thank you M.S. Vani for your comments. Janisha Farms did conduct soil tests and there is not much variability within fields with heavy soils. Fields with light soils have a different quality compared to heavy soils. Thanks for sharing your observations on percentage of productive tillers. We will see how the next season turns out to be.

admin says:

Jan 18, 2011

Thank you Dr. Norman for your valuable comments and insight. We will continue to practice SRI and experiment on single seedling at 20×20 the next season. We totally agree with you on improving the soil microbial populations organically and will provide you the data in forthcoming seasons.

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