The System of Rice/Crop Intensification Utilizes simple principles to provide plants an ideal growing environment
Interview by Paul Meyer
The System of Rice Intensification is an agronomic approach that was serendipitously discovered in Madagascar by a French priest and popularized by a university in New York, utilizing a discovery — made by Japanese scientists in the 1930s but, due to WWII, never translated into English — that follows the pattern in nature we now call the Fibonacci sequence. This is the unlikely and fascinating story of SRI — a set of principles that has enable increased profitability and improved yields for growers of rice and other crops across the world since the 1980s. It is only now beginning to be picked up among growers in industrialized nations like the United States. Dr. Erika Styger is one of the researchers at Cornell who has been working to promote SRI for the past several decades. She is beginning to work with growers here in the states as well to implement these principles. SRI/SCI is applicable on operations of all scales and offers a framework to allow plants to best express their natural traits.
Acres U.S.A. How does a professor of tropical agronomy end up in New York State at Cornell?
Erika Styger: Good question! Cornell has a big agriculture school, with many tropical specialists. There’s not much local fieldwork, but I have actually been working with some farmers in the Hudson Valley on growing SRI rice. Acres U.S.A. Do you get to travel regularly to tropical places, though? Styger. Oh, yes, that is where my work is. With COVID it was very difficult, but travels are picking up again.
Acres U.S.A. Where do you have research projects right now?
Styger: I work mostly in West Africa, and I have a research project in Suriname on rice diversity. I also have started to work in the south of the U.S.
Acres U.S.A. Great. So, for those who’ve never heard of it, what is SRI, and why is it important?
Styger: SRI — the System of Rice Intensification — is an agronomic approach. It’s a management approach to rice production, although the same approach can apply to many other crops. It’s about managing plants, soil, nutrients and water: how the farmer manages the crop.
The goal of the method is for the plant to express its full genetic potential. I think that SRI shows us — it showed me, when I first learned about it — that most of the time, when implementing common agricultural practices, we don’t actually listen to the plant or give it what it wants and needs.
Acres U.S.A. Why did SRI start with rice?
Styger: Rice is a very interesting crop because it has a high plasticity. It can be planted in highly unfavorable conditions — you can produce a seedling, cut its roots, cut its leaves, and stick it in the mud. Any other crop might die, but rice will recover and regrow. Sometimes growers don’t pay much attention to it because rice is so robust.
But when you start using the SRI method, you realize that these rice plants have something to offer that we never realized. I’ve traveled to 30 countries and have met with SRI farmers in Asia, Africa and Latin America, and that’s what I hear. When farmers first see an SRI plant, they’re like, “Wow, I’ve been growing rice my whole life, but I have never seen a plant grow like that.”
SRI is an agro-ecological approach because it has a lot to do with how we optimize the ecological processes, so that the plant can express its potential. But SRI is not a given, boxed-in method. It’s more like a process of approaching agronomy and agriculture a little differently.
Acres U.S.A. In the regenerative livestock world, we talk about the “pigness of the pig” — giving the pig or the chicken or the cow the environment they want to be in. So, SRI is kind of similar, but with plants.
Styger: Yes, exactly.
Acres U.S.A. Can you talk about the history of SRI — how it was developed?
Styger: The SRI method was developed in Madagascar in the 1980s by a French Jesuit priest named Father Henri de Laulanié. He was working with farmers, and his goal was to help people to have a better life through improved agriculture. Together, they were experimenting with rice planting. At one point, the rainy season started early and the plants in the nursery were still too young and too small to transplant, plus they didn’t have enough seedlings. They had to decide whether to plant or to wait — because if you wait, yields will most likely decline.
So, they planted, and because they had fewer seedlings, they gave each plant more space than was their usual practice. To everyone’s surprise, that year the yield was higher than it had ever been. So, they continued experimenting and synthesizing different practices — although SRI is more than just the practices.
The usual practice planting rice, in many countries, is to produce seedlings in nurseries for 30-60 days. Seedlings may get even older before transplanting, if the rainy season starts late or when farmers’ soil preparation is delayed. During transplanting, farmers usually take several seedlings — three to five, and I’ve even seen 10 to 15 — clump them together, and plant them into the mud or in standing water. Because the plants are already old and weak, growers space them close together: around 15 centimeters apart. After planting, the field is flooded from the beginning to the end of the growing season, then often drained two weeks before harvest. Growers may use a variety of fertilizers, especially urea.
With SRI, though, seedlings are transplanted much earlier. They are at the two-leaf stage: eight to 12 days old, instead of 30 to 60. Single seedlings are planted — not clumps of seedlings — and there’s a wide spacing — 25 by 25 centimeters or more. That reduces seed use by 90 percent. Then, in the vegetative phase, irrigation is only done intermittently. Growers irrigate a bit, let the paddy dry, and then come back and irrigate a little more.
Acres U.S.A. And compost is typically used as fertilizer, correct?
Styger: Yes. Compost and organic matter are added ahead of the growing season. SRI doesn’t have to be organic, but it emphasizes building up soils, which will allow growers to reduce their chemical inputs. I’ve seen farmers who no longer need to apply any fertilizers, but in many instances, farmers may still add a little urea later in the growing process. Father Laulanié didn’t say much about organic fertilization because growers in Madagascar were already doing that. He did recommend to continue using organic manure, so that there wouldn’t be any need to move toward chemical fertilizers.
Cornell University had a project in Madagascar in the mid-1990s. The project team worked to prevent deforestation by introducing improved agricultural practices as an alternative to the traditional slash-and-burn farming. They heard about SRI, and although surprised and a bit skeptical about claims that it increases yields by 50 or 100 percent, the Cornell team, led by Dr. Norman Uphoff, began testing the SRI method. After three consecutive years of confirmed improved rice productivity, they decided to make the method known beyond Madagascar. Dr. Uphoff, who had previously worked on rice production, had a large international network and traveled a lot, so he began to give talks about the method. People started to test SRI in different countries. I think the first reports came out in the year 2000. Today SRI has been validated and adopted, at different levels, in more than 60 countries.
Acres U.S.A. We’ve touched on some of the key principles — transplanting an eight- to 15-day-old seedling at wider spacings, less irrigation than normal, the addition of organic matter. Can you talk about cultivation as well — aeration with a tool as opposed to simple hand weeding? That’s a key aspect, too, isn’t it?
Styger: It is. We are making a distinction between principles of SRI and the associated practices. It’s important to anchor the method in principles, because when SRI started to spread around the world, everybody began doing a slightly different version of it. People would adapt SRI to their own environments, whether a desert or a rainforest, the uplands or the lowlands. Some would irrigate and some could not, and some would use 12-day-old seedlings and others 15. The variety of practices started a great debate among researchers (not among farmers), which unfortunately cast doubt upon the method and for a time distracted from the task of developing innovations that work for farmers. It is therefore important to step back, look at the bigger picture, and think about the principles that guide the practices.
So, we came up with four SRI principles that are practical to apply. Principle one is to encourage early and healthy plant establishment. The second is to minimize competition among plants. The third is to build up soils so that they become richer in organic matter and beneficial soil biota. And one aspect of beneficial soil biota is that it needs aerated soil, which gets back to your question about cultivation. We can call it regenerating soils, because we know how essential it is to build back the soils that we have been degrading for so long. Finally, the fourth principle is to manage water in a way that reduces flooding and does not induce water stress.
You can apply these four principles in any environment and adapt the practices to your farming conditions. Take, for example, early healthy plant establishment — one farmer would say, “I’m going to direct-seed my rice, and I inoculate it with beneficial microorganisms so that it gets a healthy start.” Another farmer uses seedlings. Careful seed selection supports this principle. So, there are many different practices that can go with it. If you follow the principle of enriching your soil — we’re talking about 60 countries — most everyone will take a different approach. Some farmers have cattle manure, some do compost, some plant green manure. The practices can vary, and if they follow the four guiding principles, the plants can express themselves much better, become healthier and more productive, and therefore follow the SRI method. …
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