Effect of Different Nutrient Management Options on Rice under System Method of Cultivation – A review

Author(s): P. Sri Rajitha and K.I. Reddy | International Journal of Plant, Animal and Environmental Sciences | January – March 2014

Rice (Oryza sativa (L.)) is one of the most important stable food crops in the world. In Asia, more than two billion people are getting 60-70 per cent of their energy requirement from rice and its derived products. In India, rice occupies an area of 44 million hectare with an average production of 90 million tonnes with productivity of 2.0 tonnes per hectare. Demand for rice is growing every year and it is estimated that in 2010 and 2025 AD the requirement would be 100 and 140 million tonnes respectively. To sustain present food self-sufficiency and to meet future food requirements, India has to increase its rice productivity by 3 per cent per annum [21]. Rice cultivation requires large quantity of water and for producing one kg rice, about 3000 – 5000 litres of water depending on the different rice cultivation methods such as transplanted rice, direct sown rice (wet seeded), alternate wetting and drying method (AWD), system of rice intensification (SRI) and aerobic rice. Owing to increasing water scarcity, a shifting trend towards less water demanding crops against rice is noticed in most part of the India and this warrants alternate methods of rice cultivation that aims at higher water and crop productivity. There are evidences that cultivation of rice through system of rice intensification (SRI) can increase rice yields by two to three fold compared to current yield levels.

Download link: http://www.ijpaes.com/admin/php/uploads/447_pdf.pdf

‘Climate Smart’ Farms Key To Feeding The World

http://www.forbes.com/sites/bethhoffman/2014/02/07/climate-smart-farms-key-to-feeding-the-world/
A family in Orissa, India plants 'climate smart' rice using a System of Rice Intensification. Photo by Beth Hoffman.
A family in Orissa, India plants ‘climate smart’ rice using a System of Rice Intensification. Photo by Beth Hoffman.
 
The bad news is that it looks like climate change is here to stay.  The good news is that there are a number of cost effective, sustainable methods farmers can adopt immediately to lessen the blow.
 
I talked with Sonja Vermeulen, Head of Research for the CGIAR Research Program on Climate Change, Agriculture and Food Security about what farmers can do in the face of a changing climate. [See “With Climate Change, What’s Better For The Farm Is Better For The Planet” for more information and a related graphic].
 
Beth Hoffman: Can you summarize – What are some of the main “take aways” from the data CGIAR has collected over the years regarding climate adaptation and mitigation for farmers?  If you were going to relate just a few things that were most important, what would you tell people?
 
Sonja Vermeulen: One of the key messages is that there are potential triple wins – for adaptation, mitigation and food security – which is increasingly being called “climate smart agriculture.”
 
A simple example is, if a farmer increased the organic matter in their soil, that increases the carbon storage – a mitigation function – but more organic matter also means better water capacity.  So that means you are much better able to deal with delayed onset of rains or dry spells, which are the kinds of problems farmers are dealing with under climate change.  The increased organic content would also raise the fertility of the soil which would also be better for yields and for food security.
 
There are also many things that farmers can do on their own, by themselves, soon, like increasing the diversity of what they’ve got planted, or changing the planting dates and what they feed to animals.  That’s very good within near term.
 
But for longer term climate change on a wider scale, we need bigger actions – what people are calling “transformative adaptation.”  An example would be that coffee systems are extremely sensitive to temperature, and science is predicting that in countries like Nicaragua and Colombia as soon as 2030 farmers might lose up to 50% of their growing area or more.  So there you need much bigger adaptation actions – farmers would have to move out of coffee and into a different crop and coffee companies would need to change where they are sourcing their beans.
 
It is also important to note that there is also a lot that government policies and companies can do to help.  For example, farmers often need support in order to make changes.  Sometimes that is with direct investment, as we can see with the example of mangrove improvements or improving infrastructure. Access to better roads or inputs, for example, can really help farmers, particularly in developing nations.
 
Policy changes too,  like promoting agroforestry, can also make a big difference.  In Niger, for example, over 5 million hectares – an additional 20 million trees – have been planted by farmers themselves on their own farms.  What allowed that to happen, among other things, was a simple change in law that allowed farmers to have a resource ownership over the trees, whereas before it was owned by the Forest Department and there wasn’t much incentive to plant trees.  So this simple change in policy at a national level allowed this huge scale to be reached and farmers reaped the benefits of that.
 
BH: It strikes me that most of the techniques CCAFS talks about are very “low tech” – mixing cropping systems, rotating crops and livestock, using wild plant varieties, etc.  Is it true that many of the solutions CCAFS found to help in the face of climate change are not high tech?
 
Certainly in terms of moving quickly and effectively on adaptation in low resource, small holder, developing countries, the largest gains are with fairly low tech, established technologies. Many of those practices have been used for decades, if not centuries.  For example, digging terraces to manage erosion and making sure there are buffers of mangroves – these are things we already knew about.
 
But in some cases there are new techniques, like alternate wetting and drying of rice fields.  In 2005, farmers and researchers learned that if you drain rice fields periodically, and re-wet, farmers can get a lot of savings in irrigation and energy costs.  A side benefit was that it also lowers methane emissions from rice (rice fields are one of biggest methane emitters).  A great additional win was higher yields.  There are also very high tech, more sophisticated farming methods that can help, like micro dosing – pumping in exactly the right amount water and nutrients directly to the roots.
 
For the most part, the “new” technologies specific to climate are focused on – how can we predict patterns better and communicate that information effectively to farmers?   Farmers – particularly in poorer countries – are very widely dispersed and may not have high literacy.  And so we need to do a lot of work to get farmers better climate information so they can make better decisions on a day by day, year by year basis.
 
Thinking about the future of food security and feeding the 9 billion under climate change doesn’t just require attention to how much food we are producing.  There are also trade barriers, rising food prices, and distribution which are also issues.  Can we also find better ways to distribute and waste less food?  An FAO report last September found we throw away 1/3 of food, and so solving consumption patterns is also part of the puzzle.
 
BH: What makes these methods “sustainable”?  How are you using the term?
 
A big theme that is emerging is an idea of sustainable intensification.
 
The idea here is that one of the biggest impacts farming has on greenhouse gas emissions – but also on biodiversity – is its impact on forest clearance.  It actually makes more sense to grow more on smaller area – even if that means using more inputs like fertilizer – so as long as what you do at the same time is leave a larger area of forest.  You need to think at the landscape level when you are thinking about if what is going on on the farm is sustainable or not.
 
That said, we also want to think about what can be done to increase yields on smaller areas while increasing inputs as little as possible.  You want to not use more fertilizer, not to use more energy, but in some cases you will have to do a little of that, especially in very low input systems in Africa where they use less than 5% of fertilizer levels used in Asia for instance.
 
And so we might see things which have not traditionally counted as “sustainable” or “ecolological” in this case considered good practice, as long as it saves forests.  What we are saying is what we don’t have a vision of absolute perfection, where we want every farm to be self contained with internal recycling on farm – we just don’t think that is achievable.  But we do think that almost any farming system in world can improve its sustainability.  They can all improve their environmental management.
 
Advanced economies have made huge gains here as well.  Between 1990-2010, Denmark decreased its agricultural emissions by 20 percent, with no loss whatsoever in profitability.  So there is enormous scope in becoming more sustainable in almost any farming system.
 
Sustainability also needs to take into account the whole food chain.  For example, you might argue that finding ways to grow tobacco or a similar crop with less fertilizer would be really good.  But at a larger scale you may say – maybe that is not really the best use of our agricultural land, and in fact the best thing we can do for sustainability is to grow something else.  Tobacco is particularly unpopular now around the world, but that would also apply to the amount of meat we produce or dairy.  You would need to weigh the benefits as compared to more plant based diets.

How can we grow more rice – with less land, water and pollution?

http://www.edf.org/blog/2013/07/31/how-can-we-grow-more-rice-%E2%80%93-less-land-water-and-pollution

Kritee / Published July 31, 2013 in Economics

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(This post was co-authored by Richie Ahuja.)

Rice feeds the world. It provides more calories to humans than any other food, and more than a billion people depend on rice cultivation for their livelihoods.

In fact, rice is central to existence in many nations. For example, in 2008, when rice prices tripled, the World Bank estimated that an additional 100 million people were pushed into poverty. No wonder that changes in the price and availability of rice have caused social unrest in developing countries.

To keep rice prices affordable as populations increase, the International Rice Research Institute estimates that anadditional 8-10 million tons of rice will need to be produced worldwide every year. But a report from the International Food Policy Research Institute estimates that by 2050 rice prices will increase some 35% because of yield losses due to climate change. Some 90% of the world’s rice is grown in Asia, on more than 200 million small scale farms, most no larger than an acre.

These colliding trends mean that the world must learn to produce more rice – and to do it with less land, less water and less labor. That means devising more efficient and profitable production systems that are resilient to climate change and contribute less to it. This is exactly the challenge EDF and its partners have taken up in India, a country where roughly 500 million of the world’s 2.3 billion people in small-scale farming families live and earn $2 – $4 a day.

Rice farming releases greenhouse gasses more potent than carbon

When organic material decays without oxygen, as it does in water-logged rice paddies, soil microbes generate methane, a greenhouse gas with 25 times more warming potential than CO2. In India, rice methane emission account for about 10% of the nation’s total greenhouse gas (GHG) emissions.

Lately there is growing awareness that when rice is grown under dryer and aerated conditions, nitrous oxide emissions from rice can be as (or even more) significant as methane emissions. Nitrous oxide has about 300 times more warming potential than CO2. It has not yet been estimated what percentage of nitrous oxide emissions in India, or for that matter other rice growing regions in Asia, come from rice cultivation.

Partnering with NGOs in India yields a promising future

The rice farmers in South India are working with non-governmental organizations that are part of a broad coalition called the Fair Climate Network. EDF’s science team is working with these NGOs to develop an environmentally sustainable and economically profitable way to farm rice that will increase climate resilience and decrease GHG emissions.

With our partners, we are developing rice farming practices that change water, fertilizer and organic matter management such that GHG emissions go down as rice yield and farm profitability stay stable or go up. Our partners are working with thousands of rice farmers to record all the farm level data (methods of tilling and weeding, types of fertilizer used, amount of water used and harvest yields) necessary to understand the economic and environmental impacts of their work.

We have also developed protocols to quantify everything: yields, production costs, and emissions of nitrous oxide and methane from the rice fields. Our partners have even set up field laboratories in rural South India to constantly monitor GHG emissions. Our preliminary research work in fields “adopted” by EDF’s partners shows that there is potential to reduce GHG emissions by 2-5 metric tons per acre per year which is same as taking of an average American car off the road for a year.

Eventually, we expect to have enough data to make a case for low carbon farming of rice throughout all of South India. If low carbon rice farming becomes the standard just in all rice growing farms in South Indian states where we are currently active, we can decrease GHG emissions by 40-100 million tons of CO2e per year while saving water, improving farm incomes and protecting rice yields. This reduction is roughly equal to taking 10 million American cars off the road or taking 10-20 coal power plants off the grid. To make this possible, we will have to raise resources for outreach and the transactions costs of monitoring and verifying the GHG reductions.

The potential for this kind of research to support development, food and political security, while mitigating climate change is enormous. That’s something to think about the next time you have a bowl of rice.

The Whole Truth On A Grain Of Rice – An international row over a ‘world record’

 

TI
Sow be it Paddy crop being laid out in Gaya

AGRICULTURE: RICE PRODUCTION

UTTAM SENGUPTA, OUTLOOK, MARCH 11, 2013

“It’s 120 per cent fake,” Professor Yuan Long Ping (82), hailed as the father of ‘hybrid rice’ in China, had fumed last week in reaction to the claim that five farmers from Bihar had all individually grown more rice per hectare than the ‘world record’ of 19.4 tonnes per hectare in China—the best figure being 22.4 ton­nes. He would believe the claim, he said, only if the record was repeated.

He had reasons to be sceptical. With average yield being 6.5 tonnes per hectare in China and only 3.3 tonnes in India, it was certainly too good to be true. Moreover, the claim dated back to 2011 but had just been validated by the international community of scientists. Prof Yuan had also examined photographs of the crop and found the grains to be deficient. And one Bihar farmer was quoted by some reports as saying that they had very little sunshine in 2011, which the professor pointed out was essential for a good crop.

Even more importantly, it had taken him 40 years of research and fieldwork to achieve the world record in China. But the farmers in Bihar had taken to the System of Rice Intensification (SRI) for the first time in 2010-11.

Multinational seed corporations, rice research institutes funded by the World Bank and scientists have been struggling for the past several decades to improve the yield, without much success. But SRI, which was first initiated in 1983 by a French Jesuit priest in Madagascar, seems to have finally achieved a breakthrough and without much assistance from them either.

Officials in Bihar brush aside the cri­ticism from China. “There was a stream of scientists from India and abroad, but no Chinese scientist visited Nalanda to examine the claim,” says Rajiv Ranjan, a young agriculture gra­duate posted in Nalanda. “The world record was set on a dem­onstration plot and measured before both scientists and farmers.” Ranjan has now written to Prof Yuan and explained the details.

Dr Norman Uphoff of Cornell Univer­sity goes on to elaborate, “These results were achieved with hybrid var­ieties which derive from Yuan’s own innovation of hybridising rice, considered for decades by most rice scientists to be impossible.” Adds Amir Kassam of the Food and Agriculture Organisation, “Go to the fields and see the evidence.”

Nitish Kumar—not the Bihar chief minister, but a farmer with a land holding of just over an acre—told Outlook that the last few years had made a definite difference. “Earlier I used to struggle to feed even four people. But now I am comfortable feeding eight,” he said. Teacher and farmer Farrukh Nadim echoes the claim. “The new technique has certainly doubled, even trebled, the yield and farmers who could barely afford a bicycle are now seen on motorcycles. The prosperity is very visible.” Expec­tedly, land prices too have skyrocketed in the district.

As a technique, SRI requires much less water and does not use chemical fertilisers or GM seeds. Since every kilo of rice has traditionally required 4,000-5,000 litres of water, a 20 to 30 per cent of water saved is considered a major leap forward indeed. Being labour-intensive, the technique has been dismissed as “a waste of time” in much of the Western world. But in the populous rice-growing areas in Asia, where the average plot size is often less than a hectare, it promises to be nothing short of revolutionary.

SRI, as Louisiana State University pro­fessor emeritus Dr Manjit Kang told Outlook in an e-mail, involves transplan­ting very young seedlings, much younger than used in the traditional system; placing only one germinating seed in the field instead of bunching them tog­ether; keeping the soil just wet and not flooding it with water; and keeping the seeds equidistant between and within rows so that each seed gets its share of air, moisture and sunshine.

With rice being the staple of half the world, we may just have seen the begi­nning of the next green revolution.

India’s rice revolution

#SRI #AgrarianCrisis #RiceRevolution

In a villager in India’s poorest state, Bihar, farmers are growing world record amounts of rice – with no GM, and no herbicide. Is this one solution to world food shortages?

  • Sumant KumarView larger picture
Sumant Kumar photographed in Darveshpura, Bihar, India. Photograph: Chiara Goia for Observer Food Monthly

Sumant Kumar was overjoyed when he harvested his rice last year. There had been good rains in his village of Darveshpura in north-eastIndia and he knew he could improve on the four or five tonnes per hectare that he usually managed. But every stalk he cut on his paddy field near the bank of the Sakri river seemed to weigh heavier than usual, every grain of rice was bigger and when his crop was weighed on the old village scales, even Kumar was shocked.

This was not six or even 10 or 20 tonnes. Kumar, a shy young farmer in Nalanda district of India’s poorest state Bihar, had – using only farmyard manure and without any herbicides – grown an astonishing 22.4 tonnes of rice on one hectare of land. This was a world record and with rice the staple food of more than half the world’s population of seven billion, big news.

It beat not just the 19.4 tonnes achieved by the “father of rice”, the Chinese agricultural scientist Yuan Longping, but the World Bank-funded scientists at the International Rice Research Institute in the Philippines, and anything achieved by the biggest European and American seed and GM companies. And it was not just Sumant Kumar. Krishna, Nitish, Sanjay and Bijay, his friends and rivals in Darveshpura, all recorded over 17 tonnes, and many others in the villages around claimed to have more than doubled their usual yields.

The villagers, at the mercy of erratic weather and used to going without food in bad years, celebrated. But the Bihar state agricultural universities didn’t believe them at first, while India’s leading rice scientists muttered about freak results. The Nalanda farmers were accused of cheating. Only when the state’s head of agriculture, a rice farmer himself, came to the village with his own men and personally verified Sumant’s crop, was the record confirmed.

A tool used to harvest riceA tool used to harvest rice. Photograph: Chiara GoiaThe rhythm of Nalanda village life was shattered. Here bullocks still pull ploughs as they have always done, their dung is still dried on the walls of houses and used to cook food. Electricity has still not reached most people. Sumant became a local hero, mentioned in the Indian parliament and asked to attend conferences. The state’s chief minister came to Darveshpura to congratulate him, and the village was rewarded with electric power, a bank and a new concrete bridge.

That might have been the end of the story had Sumant’s friend Nitish not smashed the world record for growing potatoes six months later. Shortly after Ravindra Kumar, a small farmer from a nearby Bihari village, broke the Indian record for growing wheat. Darveshpura became known as India’s “miracle village”, Nalanda became famous and teams of scientists, development groups, farmers, civil servants and politicians all descended to discover its secret.

When I meet the young farmers, all in their early 30s, they still seem slightly dazed by their fame. They’ve become unlikely heroes in a state where nearly half the families live below the Indian poverty line and 93% of the 100 million population depend on growing rice and potatoes. Nitish Kumar speaks quietly of his success and says he is determined to improve on the record. “In previous years, farming has not been very profitable,” he says. “Now I realise that it can be. My whole life has changed. I can send my children to school and spend more on health. My income has increased a lot.”

What happened in Darveshpura has divided scientists and is exciting governments and development experts. Tests on the soil show it is particularly rich in silicon but the reason for the “super yields” is entirely down to a method of growing crops called System of Root Intensification (SRI). It has dramatically increased yields with wheat, potatoes, sugar cane, yams, tomatoes, garlic, aubergine and many other crops and is being hailed as one of the most significant developments of the past 50 years for the world’s 500 million small-scale farmers and the two billion people who depend on them.

People work on a rice field in BiharPeople work on a rice field in Bihar. Photograph: Chiara GoiaInstead of planting three-week-old rice seedlings in clumps of three or four in waterlogged fields, as rice farmers around the world traditionally do, the Darveshpura farmers carefully nurture only half as many seeds, and then transplant the young plants into fields, one by one, when much younger. Additionally, they space them at 25cm intervals in a grid pattern, keep the soil much drier and carefully weed around the plants to allow air to their roots. The premise that “less is more” was taught by Rajiv Kumar, a young Bihar state government extension worker who had been trained in turn by Anil Verma of Professional Assistance for Development Action, an Indian NGO which has introduced the SRI method to hundreds of villages in the past three years.

While the “green revolution” that averted Indian famine in the 1970s relied on improved crop varieties, expensive pesticides and chemical fertilisers, SRI appears to offer a long-term, sustainable future for no extra cost. With more than one in seven of the global population going hungry and demand for rice expected to outstrip supply within 20 years, it appears to offer real hope. Even a 30% increase in the yields of the world’s small farmers would go a long way to alleviating poverty.

“Farmers use less seeds, less water and less chemicals but they get more without having to invest more. This is revolutionary,” said Dr Surendra Chaurassa from Bihar’s agriculture ministry. “I did not believe it to start with, but now I think it can potentially change the way everyone farms. I would want every state to promote it. If we get 30-40% increase in yields, that is more than enough to recommend it.”

The results in Bihar have exceeded Chaurassa’s hopes. Sudama Mahto, an agriculture officer in Nalanda, says a small investment in training a few hundred people to teach SRI methods has resulted in a 45% increase in the region’s yields. Veerapandi Arumugam, the former agriculture minister of Tamil Nadu state, hailed the system as “revolutionising” farming.

SRI’s origins go back to the 1980s in Madagascar where Henri de Laulanie, a French Jesuit priest and agronomist, observed how villagers grew rice in the uplands. He developed the method but it was an American, professor Norman Uphoff, director of the International Institute for Food, Agriculture and Development at Cornell University, who was largely responsible for spreading the word about De Laulanie’s work.

Given $15m by an anonymous billionaire to research sustainable development, Uphoff went to Madagascar in 1983 and saw the success of SRI for himself: farmers whose previous yields averaged two tonnes per hectare were harvesting eight tonnes. In 1997 he started to actively promote SRI in Asia, where more than 600 million people are malnourished.

“It is a set of ideas, the absolute opposite to the first green revolution [of the 60s] which said that you had to change the genes and the soil nutrients to improve yields. That came at a tremendous ecological cost,” says Uphoff. “Agriculture in the 21st century must be practised differently. Land and water resources are becoming scarcer, of poorer quality, or less reliable. Climatic conditions are in many places more adverse. SRI offers millions of disadvantaged households far better opportunities. Nobody is benefiting from this except the farmers; there are no patents, royalties or licensing fees.”

Rice seedsRice seeds. Photograph: Chiara GoiaFor 40 years now, says Uphoff, science has been obsessed with improving seeds and using artificial fertilisers: “It’s been genes, genes, genes. There has never been talk of managing crops. Corporations say ‘we will breed you a better plant’ and breeders work hard to get 5-10% increase in yields. We have tried to make agriculture an industrial enterprise and have forgotten its biological roots.”

Not everyone agrees. Some scientists complain there is not enough peer-reviewed evidence around SRI and that it is impossible to get such returns. “SRI is a set of management practices and nothing else, many of which have been known for a long time and are best recommended practice,” says Achim Dobermann, deputy director for research at the International Rice Research Institute. “Scientifically speaking I don’t believe there is any miracle. When people independently have evaluated SRI principles then the result has usually been quite different from what has been reported on farm evaluations conducted by NGOs and others who are promoting it. Most scientists have had difficulty replicating the observations.”

Dominic Glover, a British researcher working with Wageningen University in the Netherlands, has spent years analysing the introduction of GM crops in developing countries. He is now following how SRI is being adopted in India and believes there has been a “turf war”.

“There are experts in their fields defending their knowledge,” he says. “But in many areas, growers have tried SRI methods and abandoned them. People are unwilling to investigate this. SRI is good for small farmers who rely on their own families for labour, but not necessarily for larger operations. Rather than any magical theory, it is good husbandry, skill and attention which results in the super yields. Clearly in certain circumstances, it is an efficient resource for farmers. But it is labour intensive and nobody has come up with the technology to transplant single seedlings yet.”

But some larger farmers in Bihar say it is not labour intensive and can actually reduce time spent in fields. “When a farmer does SRI the first time, yes it is more labour intensive,” says Santosh Kumar, who grows 15 hectares of rice and vegetables in Nalanda. “Then it gets easier and new innovations are taking place now.”

In its early days, SRI was dismissed or vilified by donors and scientists but in the past few years it has gained credibility. Uphoff estimates there are now 4-5 million farmers using SRI worldwide, with governments in China, India, Indonesia, Cambodia, Sri Lanka and Vietnam promoting it.

Sumant, Nitish and as many as 100,000 other SRI farmers in Bihar are now preparing their next rice crop. It’s back-breaking work transplanting the young rice shoots from the nursery beds to the paddy fields but buoyed by recognition and results, their confidence and optimism in the future is sky high.

Last month Nobel prize-winning economist Joseph Stiglitz visited Nalanda district and recognised the potential of this kind of organic farming, telling the villagers they were “better than scientists”. “It was amazing to see their success in organic farming,” said Stiglitz, who called for more research. “Agriculture scientists from across the world should visit and learn and be inspired by them.”

A man winnows rice in Satgharwa villageA man winnows rice in Satgharwa village. Photograph: Chiara GoiaBihar, from being India’s poorest state, is now at the centre of what is being called a “new green grassroots revolution” with farming villages, research groups and NGOs all beginning to experiment with different crops using SRI. The state will invest $50m in SRI next year but western governments and foundations are holding back, preferring to invest in hi-tech research. The agronomist Anil Verma does not understand why: “The farmers know SRI works, but help is needed to train them. We know it works differently in different soils but the principles are solid,” he says. “The biggest problem we have is that people want to do it but we do not have enough trainers.

“If any scientist or a company came up with a technology that almost guaranteed a 50% increase in yields at no extra cost they would get a Nobel prize. But when young Biharian farmers do that they get nothing. I only want to see the poor farmers have enough to eat.”

http://www.guardian.co.uk/global-development/2013/feb/16/india-rice-farmers-revolution

Doing Different Things or Doing It Differently? – Rice Intensification Practices in 13 States of India

Can the System of Rice Intensification be the answer to meet the country’s future rice demand? A macro-level study covering 13 major rice-growing states indicates that fields with SRI have a higher average yield compared to non-SRI fields. Out of the four core SRI components typically recommended, 41% adopted one component, 39% adopted two to three components, and only 20% adopted all the components. Full adopters recorded the highest yield increase (31%), but all adopters had yields higher than those that used conventional practices. They also had higher gross margins and lower production costs compared to non-SRI fields. Though the rice yield of the country can significantly increase under SRI and modified SRI practices, there are major constraints that have to be tackled before this can be achieved.
 
Vol – XLVIII No. 08, February 23, 2013 | K Palanisami, K R Karunakaran, Upali Amarasinghe, and C R Ranganathan Special Articles

http://www.epw.in/system/files/pdf/2013_48/08/Doing_Different_Things_or_Doing_It_Differently.pdf

 

Differential responses of system of rice intensification (SRI) and conventional flooded-rice management methods to applications of nitrogen fertilizer

Author(s): Amod Kumar Thakur, Sreelata Rath, Krishna Gopal Mandal
Abstract
 
Background
 
Rising food demand, slowing productivity growth, poor N-use efficiency in rice, and environmental degradation necessitate the development of more productive, environmentally-sound crop and soil management practices. The system of rice intensification (SRI) has been proposed as a methodology to address these trends. However, it is not known how its modified crop-soil-water management practices affect efficiency of inorganic nitrogen applications.
 
Methods
 
Field experiments investigated the impacts of SRI management practices with different N-application rates on grain yield, root growth and activity, uptake of N and its use-efficiency, leaf chlorophyll content, leaf N-concentration, and photosynthetic rate in comparison with standard management practices for transplanted flooded rice (TFR).
 
Results
 
Overall, grain yield with SRI was 49 % higher than with TFR, with yield enhanced at every N application dose. N-uptake, use-efficiency, and partial factor productivity from applied N were significantly higher in SRI than TFR. Higher leaf nitrogen and chlorophyll contents during the ripening-stage in SRI plants reflected delayed leaf-senescence, extension of photosynthetic processes, and improved root-shoot activities contributing to increased grain yield.
 
Conclusions
 
Rice grown under SRI management used N fertilizer more efficiently due to profuse root development and improved physiological performance resulting in enhanced grain yield compared to traditional flooded rice.