Chapter 20: INTENSIFYING FARMING SYSTEMS AND
CAPITALIZING ON AGROECOLOGICAL RELATIONSHIPS
SRI was developed to improve irrigated rice cropping systems in Madagascar, but its ideas and methods were subsequently extended to rainfed rice cropping in a number of Asian countries (Chapter 13) and then to improving the production of finger millet, wheat, teff and other crops in Asia, Africa and Latin America (Chapter 14). In these various developments, attention was focused on a particular crop, except for the Sustainable Sugarcane Initiative in India which built into its methodology the intercropping of leguminous and other crops between the widely-spaced rows of SSI sugarcane.
This practice of intercropping sugarcane with different crops provides ground cover for the soil, curbs weed growth, and reduces soil moisture evaporation. It enhances the soil’s fertility while giving farmers additional sources of income and their families a more diversified diet. A study in Kashmir state of India, of intercropping a bean crop with SRI rice has showed that both crops can benefit from their being grown together. There can be benefits for both people and the environment from this practice of making farming systems more diverse as well as more intensive.
In recent years, the purview of SRI has been expanding from a crop-centered perspective to fit and even embed SRI ideas and methods into more complex and encompassing farming systems. In this chapter we consider how SRI’s intensification has been linked to the diversification of farmers’ production systems, connecting it with both aquaculture and horticulture as a specific example. It is illuminating to see how similar but separate initiatives arose in Cambodia and in India, one from an NGO and the farmers associated with it, and the other from a national government research institute.
In this chapter we also discuss and show examples of how SRI management is converging with Conservation Agriculture (CA), an emergent and parallel agroecological farming system. CA is part of a growing family of innovative systems that integrate biologically-based processes and potentials. Like SRI, these other farming systems are contributing to what can be characterized as a ‘re-biologization’ of agriculture.
As SRI has evolved, we are seeing beyond the synergies that have effect within the SRI system of crop management. There are further synergies to be capitalized upon within more complex farming systems. These systems by employing other crops in addition to rice make the resources of land, water, seeds, and nutrients more productive while economizing as much as possible on labor inputs.
INTENSIFICATION WITH DIVERSIFICATION, LINKING SRI WITH AQUACULTURE AND HORTICULTURE
As its name indicates, SRI focuses on helping farmers improve their rice production. But it can also be made part of more encompassing efforts to raise farms’ productivity. We consider here two matching initiatives that have sought to combine the productivity gains of SRI with raising fish, fruits and vegetables, with remarkable synergistic effect. By moving SRI beyond a cropping-systems framework and into a broader farming-systems approach it is possible to improve households’ nutrition as well as their income significantly.
One initiative was in Southeast Asia, initiated by farmers and the NGO working with them, while the other was in South Asia, where researchers who were already engaged with the evaluation of SRI undertook rigorous, replicated trials to assess what could be achieved by combining the utilization of SRI with complementary agricultural activities.
Once farmers working with the NGO CEDAC found that they could raise the productivity of their land, labor and water by employing SRI methods, some of them began to ‘complexify’ their farming systems. They sought to take more advantage of the gains in productivity that they were obtaining with the new methods of rice farming. In what CEDAC called ‘multi-purpose farming’ (MPF), first dozens and then hundreds of innovative farmers redeployed some of their limited land resources out of rice production and into other productive activity having seen that they could meet their families’ staple food needs with less area than previously.
On some of the land area that these pioneering farmers had been using to grow rainfed rice, they each constructed a small pond to capture and store rainwater runoff during the rainy season, to use in the subsequent dry season. Previously they had been raising just one crop of unirrigated rice each year, sowing it after the rains started. But once they had some capacity to store water, they could grow rice and other crops in both the wet and the dry seasons.
The productivity gains that these farmers derived from using SRI methods permitted them to diversify their farming systems. They took about a third of their paddy land out of rice production and with this land diversified their farming activities to give them year-round streams of output and income.
In 2007, when the number of farmers practicing MPF had grown from about 200 in 2002 to almost 400, CEDAC put together and produced a manual that explained this strategy of ‘intensification with diversification.’ The manual published in both Khmer and English contained diagrams of the redesigned production systems that five of the best MPF farmers had devised for themselves, as well as details on their kinds, amounts and costs of production. These smallholding farmers had, on average, only two-thirds of a hectare of land. Sixty percent of this, about one acre, they kept in rice production, while the rest was devoted to the installation of a pond and canals (about 15%) and to producing fish, vegetables, fruit, and small livestock (about 25%).
On average, the investment that the 5 farmers had to make to convert their all-rice operation to diversified production cost only about US$ 300. An important consideration for these farmers was that this investment could be made incrementally, over several years. It was modest enough so that the farmers did not have to borrow money and go into debt. The income stream that the farmers could generate from their newly-configured uses of their land, labor, water and capital was close to US$ 600 per year, compared with less than US$ 200 before they converted their farms to MPF, making this a very profitable investment.
CEDAC’s director, Y.S. Koma, twice took me to see the MPF operations on the farm of one of these five innovators, Roas Mao, who showed us around his small farm with evident pride. In his pond, for example, he was raising frogs and eels in addition to fish because there was good local market demand for both frogs and eels, he explained.
Above a part of the pond’s area Roas had constructed a bamboo trellis onto which pumpkins and squash were being grown. This expanded his horticultural area for harvesting sunlight; it also shaded the pond with the trellis and vine plants, thereby somewhat lowering the pond’s water temperature. This shading benefited the growth of the fish and the other aquatic life in the pond; and the vegetative material that dropped into the pond served as additional food for the creatures below.
Several comments that Roas made during my second visit to his MPF farm stood out in my memory.
Earlier when monocropping rainfed rice, his household had had to depend entirely upon the income that it got each year from an uncertain rice harvest, which was subject to the vagaries of weather, pests, and diseases. Now with the pond providing supplementary water for multiple crops, every week of the year his household had at least some income coming in from vegetable or other sales. He was growing, for example, more than 10 kinds of beans, each of which had a different growth cycle. This means they were harvested in different months throughout the year.
Because the net income that he derived from his diversified farming operations had quintupled, Roas had hired two of his five children to work on the family farm at a higher wage than they would have earned if they went to Phnom Penh for urban employment. Here in the village they enjoyed a better quality of life than if they were living in crowded, cramped quarters in the capital city. His other children were still in school, and paying their school fees was now easy, he said.
As we were leaving his farm in 2007, Roas commented that with this diversified system, farming was now “more fun.” Making rural life and agriculture more psychologically rewarding is in itself a significant benefit to be considered with such a diversified system.
During the rainy seasons in 2009/10 and 2010/11, Amod Thakur and colleagues at the ICAR-Indian Institute of Water Management in Bhubaneswar (Chapter 9) set up and conducted replicated trials to evaluate four different rice-based farming systems under rainfed conditions. Their fourth treatment resembled the MPF systems in Cambodia just discussed, although the system evaluated was simpler than CEDAC’s complex multi-purpose farming.
The four systems that were compared and evaluated over the two seasons were:
rainfed rice cultivation using the methods commonly employed by farmers in the region,
rainfed rice cultivation with SRI methods as considered in Chapter 13,
rainfed SRI cultivation with supplemental irrigation for the rice crop, pumped from tubewells installed on the plots being evaluated with this treatment, and
rainfed SRI cultivation with supplementary irrigation for rice plus other cropping; water was supplied from a water-harvesting pond constructed with catchment bunds around it.
All of the trial plots were the same size (350 m²), and each of the four treatments was replicated three times in each season, making 12 plots in all (24 for the two years). On the plots devoted to the fourth treatment, only three-fourths of the area (270 m²) was planted with rice. A pond was constructed on 10% of these plots (35 m²), while sloping bunds to capture rainfall runoff were made around the pond on the remaining 45 m² of the plot. On these bunds, bananas and papayas were planted (15 plants each). The pond was stocked with three species of Indian carp to be able to practice remunerative aquaculture.
The yield of paddy rice from the second treatment (rainfed SRI) was 52% greater than was obtained from the first-treatment plots (conventional rainfed rice). By adding supplemental tubewell irrigation, third-treatment plots had a paddy yield higher by another 29%. With the fourth treatment, using catchment-pond water for supplemental irrigation instead of tubewell water added a further 8% to rice yield. Why the difference between the two sources of water? The pond water was ‘less pure’ than the groundwater. Suspended or dissolved organic materials in the pond water enhanced the soil’s fertility and thus its rice production, compared to irrigating with ‘pure’ well water.
Comparisons of the phenotypical effects of SRI management practices showed the same kind of improvements in rice plants’ structure and functioning as had Thakur’s preceding research on phenotypes of irrigated SRI rice, summarized in Chapter 11. Both the leaf area index and light interception by the canopy of SRI plants were significantly higher in the fourth treatment compared to the other three. SRI plant leaves had higher levels of chlorophyll and higher rates of photosynthesis. Also rice root systems’ dry weight and exudation were significantly greater when the rice plants were grown not just with SRI methods but also in conjunction with complementary and synergistic farming activities.
An unexpected finding arose from having two years of trial results. In the first season, only about half as much rainfall was received as fell in the second season (650 mm vs. 1150 mm). Thus, there was considerable water stress in the first year. Yield from the conventional rainfed rice cropping was 30% lower in that water-short year, whereas the yield of rainfed SRI was only 9% lower, showing its greater resistance to climate-stress.
In the water-stressed first season, the yield from the rainfed SRI plots that had supplemental tubewell irrigation (third treatment) was actually 10% higher than in the second year, when there was more rainfall. Yield from the SRI plots with pond-water supplementation was 2% greater, perhaps because pond water was not quite as reliable and controllable as water sourced from a tubewell. This evaluation was consistent with the reports in Chapter 12 of the greater climate-resilience of rice under SRI management, true for rainfed as well as for irrigated rice production.
An economic evaluation of the four alternative farming systems was even more contrasting. The costs of production for the integrated system (treatment 4) were calculated to be more than four times greater than with typical rainfed rice production. Diversified production certainly requires more effort and expenditure than simple rainfed rice production. However, the economic value of its total output of rice, fish, and fruits was more than 10 times greater. This made investment in pond construction and management together with complementary aquacultural and horticultural activity very profitable.
The impact that an integrated, SRI-based cropping system could have on water productivity was very dramatic, denominated in terms of rupees earned per cubic meter of water that was available for use. In conventional rainfed rice production, only a fraction of the total rainfall is put to any productive purpose, whereas with the integrated farming system, the rainfall was intensively managed and utilized in several productive ways.
The net income from standard rainfed rice cultivation per cubic meter of water was trivial, just 0.31 Rs. Practically nothing. Under the integrated management, on the other hand, the net income generated per cubic meter of rainfall was Rs. 18.91 (US$ 0.25), which was 60 times more.
More research remains to be done on these kinds of synergy for SRI practices within farming systems. But these two examples -- one a bottom-up innovation by farmers, and the other evaluated by a multi-disciplinary team of researchers -- point to additional avenues for the evolution of SRI ideas and methods, having both economic advantages and climate-change buffering impacts. There is some on-going work in Vietnam to integrate use of SRI methods for rice-growing with fish culture for synergistic effects. Other synergies among farming activities are also being experimented with, such as integrating SRI rice with home gardens and/or pig production in Tripura state of India.
The picture below was received from Indonesia in March 2021. Jatika wanted us to see a novel land and water management adaptation that is being evaluated at the SRI training center he has established at Nagrak. Young SRI seedlings are planted singly on the sides of narrow raised beds, really ridges, with water maintained in the furrows between the beds for the fish. The planting on ridges keeps the plants from being submerged as this is more favorable for root growth than flooding. Results remain to be reported.
DEVELOPING SRI WITHIN A BROADER CONTEXT
Convergence with Conservation Agriculture
One of the first agricultural scientists of international standing to understand SRI and appreciate its potentials was Amir Kassam, an agroecologist by profession and at the time a member of the staff of the secretariat that supported the CGIAR’s Technical Advisory Committee (TAC) based at FAO in Rome. During his time with the TAC Secretariat, Amir took leave for two years (1998-2000) to serve as Deputy Director-General for programs at WARDA (now AfricaRice).
Amir subsequently served as interim executive secretary of the CGIAR’s Science Committee before stepping down from that position for health reasons. Amir has also been one of the most active and effective proponents for what was initially called ‘zero-till’ or ‘no-till’ agriculture. This, like SRI, has evolved over time, with its current form widely referred to as Conservation Agriculture (CA), a more encompassing and instructive designation.
One of the things that first attracted Amir to SRI when he first arrived at WARDA was SRI’s congruence with CA as both share the same basic agronomic principles. These account for their respective improvements in factor productivity, and both are good examples of agroecological reasoning and practice. Agroecological principles map out ways for agriculture to become not only more productive, but also more sustainable and more climate-resilient.
The initial focus of CA strategy was on stopping the recurring tillage of soil, which for millennia has been a defining characteristic of agriculture. But tillage was really just a practice, not a system of production. The more holistic Conservation Agriculture as now understood is based on three interlinked pillars of practice: no or minimal mechanical disturbance of the soil; keeping the soil continually covered with vegetative material; and crop diversification with crop rotation and/or associations.
The combination of these three practices puts an end to:
Repeated breaking up and turning over of the topsoil, which contributes to wind and water erosion, to the loss of carbon, nitrogen and other nutrients, and to destruction in the soil of both plant roots and beneficial soil biota so that the soil’s structure becomes less supportive of crop success.
Exposure of the topsoil to the sun, wind and rain which heats up the soil, inhibits the life in the soil, and facilitates nutrients and fine particles being blown or washed away. Protecting the soil with green manures, cover crops, mulch, compost or any other vegetative cover, on the other hand, helps to maintain soil temperature within a more favorable range and protects the soil, supplying nutrients in organic forms.
Monocropping with the same kind of crop plants being grown on the soil year after year. This current practice reduces the diversity of root exudation (Chapter 4) and the diversity and abundance of the soil biota (Chapter 5). Increasing the life in the soil can fix, solubilize, immobilize (conserve), and mobilize a variety of macro- and micronutrients to provide better plant nutrition.
Traditionally, irrigated rice production has involved the puddling and tilling of paddy soils before seedlings are transplanted into them. This practice when repeated breaks down the soils’ structure and creates an impermeable layer of soil, called a pan, below the depth to which the plough reaches. The soil above the pan is pulverized so that its particles become finer and finer and more compacted. When the soil is flooded, organisms that need oxygen cannot survive or cannot flourish. The soil becomes a very different environment for plant roots and for the organisms living there.
Conservation Agriculture purposefully creates a below-ground environment that has an abundance of life in well-structured soil, with pervasive pore spaces between larger, better aggregated soil particles and with more space created throughout the soil by the growth of roots and a variety of soil fauna like earthworms, ants and termites. Both air and water can circulate freely through such spaces that make the soil healthier and less dense. This mirrors the reduction in plant density above-ground which is an SRI precept.
Paddy soils that have been managed conventionally with puddling and flooding become quite dense. This is why the mechanical weeding with SRI, which breaks up the soil surface and effectively vents it, restores conditions of soil aeration that favor the proliferation of roots and beneficial aerobic organisms in the soil.
The benefits from frequently disturbing the soil surface via mechanical weeding (different from plowing), together with the other practices that established SRI, probably masked the benefit that can be achieved by stopping or at least minimizing the tillage of paddy soils. Fr. Laulanié did not recommend that farmers make any change in their soil management when they were preparing their rice paddies for planting.
Perhaps Laulanié thought that when he was proposing so many changes in the rice-growing practices with which farmers were familiar, he should not try to change also their time-honored practices of flooding and repeatedly tilling rice paddies before planting rice seedlings in them. Changing land preparation would be introducing even more modification of familiar practices at one time. Laulanié focused on how to get the best results from managing plants, soil, water and nutrients differently after the transplanting of widely-spaced young rice seedlings.
Our understanding of how to optimize rice crop management arising from SRI experience and theory was consistent with what people engaging with unirrigated no-till agriculture were learning and accomplishing, especially as permanent soil cover and rotation or associations of crops were incorporated into the recommendations for Conservation Agriculture. In both CA and SRI, there was a growing appreciation for what the soil biota can contribute to making soil systems healthy, fertile and sustainably productive. This led to a realization that the application of SRI principles and practices could benefit from ceasing the age-old prescription of repeatedly breaking up and breaking down paddy soils by ploughing or other forms of tillage.
It became understood that once the life in the soil is enhanced by no longer keeping the soil continuously submerged, the soil biota through their multiplication and activity can accomplish soil-improvement effects similar to what had been achieved through mechanical weeding. Soil aeration can result from biological processes and activities of soil organisms that make the soil more porous and less dense, not just through mechanical disturbance of the soil.
One element of convergence identified by Amir Kassam is reduced plant density. With CA, over time farmers use less seeds, a 50% reduction in the seeding rate is often mentioned by farmers depending on their spacing. For example, farmers in Australia have told him that after 10 years, their seed rate has been reduced by 40% compared to conventional tillage system. With rice, CA systems are that seed rates can be cut down to 10-40 kg/ha without losing yield.
By introducing a whole diversified cropping system in space and time, CA returns a lot of biomass to the soil, sustaining excellent soil health with large numbers of microorganisms and mesofauna interacting with massive root systems. Practitioners of CA have found that with higher ratios of fungi-to-bacteria, especially with masses of mycorrhizal networks, weeds are suppressed, and more carbon is sequestered in the soil, unlike with tillage or puddled systems where bacterial-rich soils have greater weed infestation and also less carbon is sequestered.
As Conservation Agriculture and SRI converge, we are seeing benefits from introducing permanent raised beds with mulch cover, as done in the Pakistan example in the preceding chapter. These beds configure the top layers of the soil so that an elevated volume of soil is established above the previous ground level. This makes it easier for crop plants’ root zones to be kept well-drained and not saturated, avoiding hypoxic soil conditions that provide insufficient or no oxygen to sustain roots and aerobic soil organisms.
With raised beds, furrows are created alongside and between them, to have channels for the distribution and drainage of water. Gardeners have known for ages that having raised-bed configurations of their gardens’ soil surface does desirable things for their horticultural production. Rice farmers are learning that there can be similar benefits from managing their fields in this way.
Weed control remains a problem for any agricultural practice except where the stock of weed seeds in the soil has become attenuated and depleted through management practices (repeated removal of unwanted plants) or by chemical means. As seen in the examples below of convergent SRI and CA practices, weed control can be undertaken on raised beds by mechanical means with minimal soil disturbance, or by employing vegetative or material ground cover that suppresses the growth of weeds. Chemical suppression of weeds remains an option, with both SRI and CA the preference is for organic or biological methods of production that make chemical means of weed control not a favored practice.
The most effective and economical means of weed control are still being worked out for no-till SRI. The principle of crop rotation is easier to follow in places like large parts of India and China where the cropping system already alternates rice crops in the wetter, warmer summer season with wheat or other crops in the drier, colder winter period. In many regions, rice is already alternated with vegetables or some other crop.
There are already some interesting examples reported from China and Vietnam where SRI rice is being grown in rotation with mushrooms or potatoes, the latter innovation winning a national award for innovation in Vietnam. In both instances, the more voluminous yield of rice straw with SRI is used to increase the farmers’ scale of production and/or to save them labor. Here we consider two examples where ‘no-till SRI’ has emerged as a convergence between SRI and CA, alternating rice with other crops.
We saw in the preceding chapter how Asif Sharif at Amir Kassam’s suggestion combined SRI ideas and principles with those of Conservation Agriculture in what Asif calls ‘paradoxical agriculture’ (PA). With PA’s high degree of mechanization, weeding and surface-soil aeration can be accomplished effectively by a self-propelled, radio-controlled tractor-weeder, shown in Chapter 19. Its effectiveness is enhanced by the precision with which seedlings are established in exactly-spaced rows on top of the raised beds, which have been made by machine. With good inter-row cultivation, there is no need for perpendicular weeding across the rows, i.e., across the beds.
As Asif’s methods curb the growth of weeds and reduce the stocks of weed seed in the soil over time, the weed control requirements recede while surface-soil aeration continues. That the crop is increasingly managed without chemicals enhances the life in the soil, creating better structured soil within the beds, and a more favorable environment for root and crop growth.
Below is seen a picture of the kind of effect that SCI-SWI changes in cultivation are having on wheat plant roots. The plant grown with PA methods is obviously the one on the left. On the right is a field of SWI wheat that was established with the practices of paradoxical agriculture, showing mulch and vigorous growth.
As noted previously, for economic reasons Asif’s PA methods are currently being used in Punjab mostly with crops like wheat, maize, sugarcane, potatoes and carrots, rather than with rice. As seen in the table below, PA management is proving to be very profitable for these other crops when they are grown on mulch-covered raised beds with no tillage after the beds have been formed and planted by machine, and with crop rotations. Soil fertilization is mostly organic and soil cover is maintained as much as possible through crop residues or cover crops.
This table was constructed from data that Asif gathered from farmers who were using and adapting the methods that he had developed based on his SRI experience. He has specially-designed machines for the various operations and for different crops. The crops that can be rotated with these main crops include legumes, garlic, melons, cucumbers, tomatoes, chilies, and sunflower. Since this system is suitable for large-scale operations, it should begin to make commercial production of many crops more agroecologically-based.
A less mechanized version of no-till SRI has been developed in Sichuan province based on raised-bed methodology. It uses clear plastic film to cover the mulched raised beds to buffer the low temperatures that significantly stunt rice seedlings in the springtime when they are transplanted. Young rice seedlings are planted through holes in the film, which conserves soil moisture and warmth, reducing evaporation, while also suppressing weed growth.
Below on the left is seen a wooden tool made by farmers to punch regularly-spaced holes into the soil for transplanting rice seedlings. In the center we see another wooden implement being used to level the tops of the raised beds, and on the right is a different roller that lays down plastic film through which seedlings are planted. The summer rice crop is alternated with rapeseed (mustard) in the winter. Rice straw residues are used for ground cover for the beds for the winter crop, and rapeseed residues are mulched under the plastic for rice.
Compared with traditional flooded rice cultivation, this use of plastic film on raised beds with widely-spaced plants promotes more abundant rice tillering by beneficially raising soil temperatures, with accompanying greater root growth. In 2006 when there was a serious drought in the province, those farmers who had adopted these no-till SRI methods were able to maintain their usual yield, and some even increased their yield, while those farmers who did not use these methods suffered substantial losses of yield.
This led to the innovation receiving support from the provincial government, and by 2009 the area where these methods were applied in Sichuan reached 66,700 hectares. The average yield increase with this combination of SRI and CA was calculated to be 2,383 kg of paddy rice per hectare, a 31% increase over farmers’ usual practice where average paddy yields are already quite high, 7.66 tonnes per hectare. With raised-bed CA technology and SRI methods, farmers’ average yield of little over 10 tonnes per hectare was achieved with less water, less fertilizer, fewer seeds, less fuel, and less labor. At the same time, environmental conditions were improved by reducing the chemical pollution of soil and water.
An analysis of the data that beyond the fourth year of using plastic film with biomass mulch on SRI rice, the yield was no longer higher than from plots where only biomass mulch was applied. This suggests that the methodology improves soil conditions over time enough so that by the fifth and sixth years the plastic film is no longer needed. This underscored that evaluations need to keep the time dimension in mind. Conditions in biological systems are dynamic, changing for better or for worse more easily than they remain the same.
Connections with other agroecological approaches
The convergence of SRI with Conservation Agriculture does not create something new. Instead, it capitalizes on and facilitates the expression of potentials that are already intrinsic in crops and in the soil systems that support them. This is why SRI methodology and CA both can give positive results in diversified farming systems with a variety of crops, not just rice.
SRI and CA are both part of a larger family of agroecological approaches to raising and sustaining the productivity of agricultural pursuits. The first agroecological revision of conventional agricultural thinking and practice was something called ‘integrated pest management’ (IPM), conceived over 60 years ago. Over the past three decades, IPM has gained wide acceptance worldwide as evidence has accumulated that chemical protection against pests and disease vectors was often counterproductive as well as increasingly costly.
This acceptance was spurred by a realization that reliance on agrochemical means of crop protection elicited resistance within target species, often quickly, so that the pesticides used became ineffective, and were replaced by new ones. The agrochemicals also adversely affected plants’ ability to resist predation and infection. Indeed, it can make them more attractive and vulnerable to pests, bacteria, fungi and even viruses. IPM practices nurtured and mobilized natural predators and beneficial microbes (‘the good guys’) to keep pests and pathogens (‘the bad guys’) in check.
Conservation Agriculture began its life about a decade after IPM began to take shape, and a decade before SRI was assembled. It required 15 years for SRI to get much attention and traction outside of Madagascar. Conservation Agriculture has always been about ten years ahead of SRI in terms of scientific, institutional and popular acceptance.
There are other management systems that have built upon the basic principles of agroecology to mobilize and benefit from crop and soil systems’ inherent biological processes and potentials. Rather than focus just of individual and separate crop species, agroecological approaches benefitted from the species’ many associations with each other and with other species -- plant, animal, and microbial.
Agroforestry is a set of practices that is grounded in agroecological thinking and precepts like CA and SRI. So is aquaculture when it is integrated with other kinds of farming, as seen in the first part of this chapter. (Aquaculture practiced as monoculture does not come into the agroecological category.) Livestock production with poultry, pigs, sheep and/or goats and with animals that contribute manure to maintaining the fertility of fields can also come under the heading of agroecology if not practiced in isolation from other farming operations. As seen in the first part of this chapter, increasingly SRI is being thought of as a member of the larger family of agroecological systems rather than as a stand-alone innovation.
Modifications of the original and subsequent versions of SRI are still being made, experimented with, and evaluated. SRI emerged specifically to improve smallholders’ irrigated rice production, attempting to reduce poor households’ hunger and poverty. But as seen in this and preceding chapters, SRI ideas and methods have been adapted to a considerable variety of crops and conditions, with the most important adjustments now being made to deal with changing climates in the world around us.
Mechanization to deal with constraints of labor supply and cost is also progressing and will be very important for expanding the scale of SRI use. These various changes are making SRI and many of its applications different from the original formulation. But it was the original ideas that set in motion the curiosity and innovation that have diversified and enriched what is today associated with the name of SRI around the world.
The aspiration of those who work with SRI ideas and methods is to make food production more robust and resilient, responding better to the conditions of this 21st century than is possible with present ‘mainstream’ agricultural technologies. Learning how to produce food with less water and other purchased inputs is becoming urgent, by enabling fewer plants to grow bigger and better root systems that support more productive and healthier plants, and by management practices that nurture more abundant and active life in the soil. Relying less on agrochemical inputs because of their adverse impacts on ecosystems and on human health is important because publics are becoming more conscious of the downsides of using inorganic, often synthetic materials to protect and stimulate crops.
Much more needs to be done and learned to produce and sustain an adequate food supply that is good not just for our sustenance, but also for our own health and for the health of natural ecosystems. While many people in the world, indeed too many, must now deal with the consequences of their overconsumption of food, even more persons are still undernourished and suffering under-fulfillment of their lives as a consequence.
Once the merits of SRI became clear several decades ago, the first requirement was to be certain that these benefits are real. Then it became important to understand how and why this higher productivity is achieved. Readers should have found ample evidence in Part I to satisfy themselves that this innovation is both real and intelligible, as well as something important for most, if not all of the world’s population.
This said, it becomes interesting and important to know how SRI as an innovation has come to be planted if not yet flourishing in more than five dozen countries around the world, countries that produce about 98% of the world’s rice. SRI is still not fully accepted by all rice scientists, and government decision-makers, donor agencies and foundations still give it less support than they give the conventional strategy of promoting new varieties and agrochemical inputs. And most important, SRI still remains to be accepted and utilized by a majority of rice farmers.
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The chapters that follow in Part II carry the SRI story forward, reporting on how a great number and variety of persons associated with a wide range of institutions have, some more and some less, advanced the acceptance of SRI’s ideas, while some others have resisted these ideas and have constrained the utilization of SRI opportunities.
Part II is not just about rice and food, or even just about agriculture. It is very much about how our current institutions and knowledge systems are functioning, and about how well they are functioning or not. The SRI story moves beyond rice with far-reaching implications for our present and our future ability to meet human aspirations and needs.
The annex that follows this chapter synthesizes and summarizes what has been learned about why SRI plants have the productivity and resilience that can be easily seen in an SRI field. Having such knowledge has not proved sufficient to get established institutions to take advantage of SRI’s new opportunities, however.
To conclude this part, we show two pictures from India. On the left is a comparison of SRI and conventional rice plants in the hands of a ‘progressive’ farmer in the state of Punjab. The profuse growth of SRI rice plant held on the left surpassed anything seen with Green Revolution technology. On the right, at the other end of the technological spectrum we see an SRI plant grown from a single, tiny 13-day-old seedling, held proudly by a tribal farmer in the state of Odisha. This expression of genetic potential improves and makes more secure the life that he and his family lead under their current subsistence conditions.
These plants are visible representations of SRI effects which are explainable by scientific research and publications, with beneficial results demonstrated around the world. Institutions working in and with the agriculture sector have been called upon to give support to the dissemination of SRI knowledge and opportunities. Their responses, reviewed in the next part of the SRI story, have evoked much satisfaction as well as disappointment.
NOTES AND REFERENCES
 See thesis by Tavseef Shah, ‘Agroecological Engineering Interventions and Sustainable Rural Development: The Case of Rice Farming in Kashmir,’ Technische Universität Hamburg, Germany (2020).
 Lim Soviet, Experiences in Multi-Purpose Farm Development: Raising Household Incomes in Cambodia by Utilizing Productivity Gains from the System of Rice Intensification, CEDAC, Phnom Penh (2007).
 A subsequent study by C. Thong and J.-C. Diepart surveying farmers in three locations of Takeo province (8 full MPF, 18 incomplete MPF, and 26 non-MPF), where farmers hired heavy machinery to dig their ponds rather do it with own or hired labor showed higher investment, about US$ 830 also favorable returns on the investment. ‘The contribution of multi-purpose farming to the food security of small-scale farmers: An agro-economic analysis in the lowland Mekong alluvial plain,’ in J.-C. Diepart, ed., Learning for Resilience: Insights from Cambodia’s Rural Communities, The Learning Institute, Phnom Penh, pp. 79-100 (2015).
 See trip reports from my visits to Cambodia in 2006, pages 19-20, and 2007, pages 6-8. See also ALiSEA report, A Model Farm for Agro-Ecology and a video posted on YouTube which show and discuss Roas Mao’s farming system.
 One thing not seen in the above picture is Roas’ ingenious use of space. He had taken discarded 2-liter plastic soda bottles and cut off their top half, filling the bottom half with soil. Into this he planted seeds of squash or other vine vegetables like bitter gourd (or bitter melon). The bottle-bottoms were suspended by wire from horizontal poles or roof edges all around the farm. The plants grew over the edge of the plastic bottle, eventually growing as much as meter or more downward to the ground.
This layout enabled the plants to harvest sunlight and produce good-quality vegetables, contributing to the household’s diet and/or income. There was little of SRI in this manner of cropping apart from the ideas of maximizing plant growth and careful management, utilizing space and sunlight that would otherwise have been unproductive.
 A.K. Thakur, R.K. Mohanty, R. Singh and D.U. Patil,’ Enhancing water and cropping productivity through Integrated System of Rice Intensification (ISRI) with aquaculture and horticulture under rainfed conditions,’ Agricultural Water Management, 161: 65-76 (2015).
 Analysis of the water from these respective sources showed more dissolved oxygen in the pond water, and multiples more of dissolved organic matter and suspended solids. There were also much higher levels of plankton, chlorophyll, and both nitrate and nitrite sources of nitrogen.
 The yield increases of rainfed SRI, the 2nd, 3rd and 4th treatments, over usual rainfed rice production in the more normal rainfall years were, respectively, 35%, 59% and 78%. In the water-stressed year, the respective increases were 78%, 152% and 163% (Figure 5 of the reference in endnote 4).
 Starting in 2013, the Center for Community Capacity Building and Rural Development in Vietnam, with support from the International Society of Environmental and Rural Development (ICERD) and in cooperation with the Thai Field Alliance, began working with farmers in three provinces to apply SRI principles in rice-fish intercropping. In recent years, due to extreme weather events, some rice cultivation areas have been badly affected by flooding so it was hoped that farmers would no longer be dependent only on rice.
One response has been to make adjustments in the usual SRI recommendations for water management to enable farmers to produce fish in SRI rice paddies. The reduced use of agrochemicals made fish culture in SRI paddies more feasible. By 2015, there were 60 farmers applying this model, as reported in a summary of 10 years of SRI experience in Vietnam (sections III.11 and V.3).
Already 20 years ago, some farmers in Madagascar were managing to produce fish in their SRI rice paddies by constructing refuges (small ponds) in a corner of their SRI fields to which fish could retreat during the periods when the rice paddies had little water and the soil was starting to dry up. When the fields were reflooded, the fish could range over the whole field, returning to the refuges as the water level ebbed.
 G.S. Yadav et al., ‘Enhancing livelihood security of small and marginal farmers in Tripura through integrated farming systems,’ Biotechnica Research Today, 2, 1302-1304 (2020). Poor households with limited land access by switching to SRI rice-growing methods with fish pond, home gardens and pig-raising, have raised their net cash input per year from less than US$ 100 to nearly US$ 600. These integrated operations require more household expenditure, but the income is increased by much more to produce large net benefits. Investments can be made incrementally, so little or no loans are needed.
 See Erick Fernandes, Alice Pell and Norman Uphoff, ‘Rethinking agriculture for new opportunities,’ in N. Uphoff, ed., Agroecological Innovations: Increasing Food Production with Participatory Development, pages 21-30, Earthscan, London.
 On this practice, see a widely-cited lecture by Felix Ponnamperuma ‘Puddling and Its Effects on Rice’ (1981).
 Another practice for which Laulanié seems to have ‘pulled his punches’ was his recommendation that farmers keep a thin layer of water (2 cm) on SRI rice paddies after the plants have flowered, rather than continue the alternate wetting and drying done before flowering (anthesis).
Amod Thakur’s research on this recommendation, comparing it with continuing alternate wetting and drying of SRI plots after flowering and re-issuing irrigation water 3 days after the field has no more standing water, has shown that when AWD is continued throughout the entire crop cycle, rice plants are phenotypically superior and more productive. A.K. Thakur, K.G. Mandal, R.K. Mohanty and S.K. Ambast, ‘Rice root growth, photosynthesis, yield, and water productivity improvements through modifying cultivation practices and water management,’ Agricultural Water Management, 206: 67-77 (2018). This modification in SRI water management should be further evaluated and adapted to local soil and climatic conditions, but it probably represents a substantial improvement in the original SRI model.
 This has been studied more with wheat than with rice, though similar agronomic effects should be similar for both. Our Cornell colleague John Duxbury has evaluated raised beds with colleagues in Bangladesh, India and Nepal for both grain crops and horticulture, documenting productivity benefits. See poster at the 4th International Crop Science Congress in 2004 which reported wheat yields on raised beds increased 18% with 32% less irrigation water compared to flat-field cultivation; also M.A.M. Miahi, Moniruzzaman, S. Hossain, J.M. Duxbury and Julie Lauren, ‘Adoption of raised bed technology in some selected locations of Rajshahi district of Bangladesh,’ Bangladesh Journal of Agricultural Research 40: 551-556 (2015).
A review of raised beds’ yield advantage for rice and wheat found this to be 29% on average for the same soil and same season. K.D. Sayre and P. Hobbs, ‘The raised-bed system of cultivation for irrigated production conditions,’ in R. Lal, P. Hobbs, N. Uphoff and D. Hansen, eds., Sustainable Agriculture and the International Rice-Wheat System, 337-355, Marcel Dekker, New York (2004).
 My first encounter with such a crop rotation for SRI was with a rice-mushroom rotational system to which Zheng Jiaguo introduced me while visiting Sichuan province in China in 2004. Farmers found that this rotation could benefit both crops. Growing a winter mushroom crop on raised beds enhanced the soil fertility for the rice crop grown on them in the summer. Not using agrochemicals with the rice crop then promoted better mushroom growth, as discussed in a trip report.
Proof that soil fertility was improved in this crop-rotation system was that farmers found their highest SRI rice yields were achieved when they spaced their rice plants more widely, at 40 × 45 cm, having only 6 plants per square meter rather than 16. This alternation of rice and mushrooms had been developed before SRI was introduced in Sichuan. However, farmers found that with SRI methods they could produce 50% more straw, which permitted them to raise 50% more mushrooms in the winter season when they had this much more straw as a substrate for growing mushrooms.
During a 2007 visit to Sichuan province, I happened to meet the president of the China Academy of Agricultural Sciences who said that an SRI rice-mushroom rotation raised the yields of the rice as well as the mushrooms. The highest rice yield in Sichuan province the previous year had been with this rice-mushroom rotation, 11.67 tonnes per hectare.
In Vietnam, Ngo Tien Dung, who gave national leadership for SRI as director of the Ministry of Agriculture and Rural Development’s Plant Protection Department (having been the country’s leader for establishing integrated pest management) started working with farmers in 2008 to develop a no-till SRI rice-potato rotation which had multiple advantages.
Within two years, this production system called ‘Growing potatoes by minimum ground disturbance method using straw’ was raising crop yields by 8-25% while reducing plant protection chemicals by 75% and water requirements by 25-67%. 28-47% less labor was required because with raised beds, there was no ploughing. The potatoes were simply covered by rice straw. This system is reported in H.V. Phu et al., ‘Adapted research on rice/potato rotation model (SRI for rice and minimum tillage method for potato) in paddy land of Phu Binh district, Thai Nguyen province,’ Thai Nguyen University Journal of Science and Technology, 226:9 (2021). http://jst.tnu.edu.vn/jst/article/view/4422 The article posted is in Vietnamese, but it can be easily machine-translated into English.
These results gave farmers an incentive not to burn their rice straw after harvest, so the new farming system reduced air pollution, an environmental hazard in Vietnam. These modifications in practice were increasing farmers’ profitability by 19-31%. In 2013, this methodology was recognized by the Ministry of Agriculture and Rural Development as a technical improvement, and by the next year, 4,500 farmers were applying this system in 22 provinces. The next year this innovation was given a national environmental prize by the Ministry of Natural Resources and Environment, and then another national award by the Ministry of Agriculture and Rural Development the following year. These events are included in a chronology of SRI development in Vietnam.
 This table is reproduced from Adhikari et al., ‘System of crop intensification for more productive, resource-conserving, climate-resilient and sustainable agriculture: Experiences with diverse crops in varying agroecologies,’ International Journal for Agricultural Sustainability (2017). See discussion on pages 21-24 of that article for more details.
 Details are given in S.H. Lu, Y.J. Dong, J. Yuan, H. Lee and H. Padilla, ‘A high-yielding, water-saving innovation combining SRI with plastic cover on no-till raised beds in Sichuan, China,’ Taiwan Water Conservancy, 61: 94-109 (2013), so the discussion here is a summary.
 This information comes from Lu et al. cited in the preceding endnote.
 Six years of data are reported in S.H. Lu, Y.J. Dong, Y. Jiang, H. Padilla, J. Li and N. Uphoff, ‘An opportunity for regenerative rice production: Combining plastic film cover and plant biomass mulch with no-till soil management to build soil carbon, curb nitrogen pollution, and maintain high-stable yield,’ Agronomy, 9 (2019). (doi 10.3901/agronomy9100600)
 As noted in Chapter 12, despite a 14-fold increase in the volume of chemical insecticides used for agricultural crop protection in the US in the last half of the 20th century, the percent of crops that were lost to insects almost doubled. David Pimentel, Techniques for Reducing Pesticides: Environmental and Economic Benefits, John Wiley, Chichester, UK (1997).
 This is explained with research justification by Francis Chaboussou in his book Healthy Plants: A New Agricultural Revolution, Jon Anderson Publishers, Charnley, UK (2004), discussed in Chapter 12. This book was published in French in 1985, but Chaboussou died shortly thereafter, so the book received little attention (except in Brazil) until an English translation was produced almost 20 years later.
 These principles are summarized by Miguel Altieri in ‘Agroecological principles for sustainable agriculture,’ in N. Uphoff, ed., Agroecological Innovations: Increasing Food Production with Participatory Development, 31-40, Earthscan, London.
 The strategy for livestock management as proposed by Allan Savory, with Jodi Butterfield, in Holistic Management: A New Framework for Decision-Making, 2nd ed., Island Press, Washington, DC, exemplifies agroecological thinking applied to livestock rearing. Savory’s insights and recommendations have value even if their merits can be and sometimes are considered to be overstated, like any new set of ideas. We have made efforts to treat SRI in a continually factual and empirical way, since any exaggeration works against the interests of farmers and their families.
 An analysis of the grants made by the Bill and Melinda Gates Foundation, the largest foundation in the world making grants for agricultural development, found that 85% of its grants went to what was classified as ‘industrial agriculture, while only 13% was granted to support agroecological initiatives. Money Flows: What Is Holding Back Investment in Agroecological Research in Africa, Biovision Foundation for Ecological Development, Zürich (2020).
PICTURE CREDITS: CEDAC (Cambodia); Asif Sharif (Pedaver); Lu Shihua (China); Amrik Singh (India); PRAGATI-Koraput (India).