Legume crops are best known for their protein-rich pulses and leaves. But some legumes are not eaten, they are called â€śgreen manureâ€ť because they are grown to fix nitrogen and add organic matter to the soil. These gifts from nature offer farmers opportunities to improve their soil, but it is still a challenge to find out which legumes work best under given conditions, as a recent experience suggests.
In two Southeast Asian countries that I visited last year, Thailand and Vietnam, farmers growing cassava on hillsides had seen their fertile topsoil washed away by torrential downpours. In some places, the soil had been further impoverished by years of using mineral fertiliser without also enriching the soil with organic matter.
Soil erosion control and soil fertility management techniques are the topics of two farmer training videos that Agro-Insight developed with CIAT (The International Center for Tropical Agriculture).
We learned that national institutes were trying to get crotolaria seed in farmersâ€™ hands while suggesting that farmers sow the seed at the first rains, and then plough the plants under six weeks later, as a green manure, just before planting the cassava.
Some farmers were eager to try out the green manure but couldnâ€™t get enough seed. As one explained: â€śWe only get one lot of crotolaria seed, and we donâ€™t know how to multiply the seed.â€ť Like other legumes, crotolaria seed is fairly easy to grow, but it will mean setting aside small seed plots, and ensuring that the harvested seed is properly stored for the next season.
Green manures may improve cassava production, benefitting farmers and cassava buyers, processors and consumers. But this will only work if more farmers know how to multiply and conserve seeds of crotolaria and other green manures. But while green manures may work well under certain conditions, other innovations with legume crops may be an even better bet.
Four years ago, I worked with ICRISAT (International Crops Research Institute for the Semi-Arid Tropics) in West Africa on a series of videos to help farmers improve soil fertility and fight striga, a parasitic weed. Cereal-legume intercropping was promoted as one way to improve soil fertility, but farmers struggled to keep their cowpea seed viable. Seed is a living thing, and so inherently delicate, but legume seeds have more oil than most seeds, and can easily become rancid. ICRISAT accepted our suggestion to develop a farmer learning video on storing cowpea seed. Farmers who watched the video were inspired to intercrop cowpeas with cereals as a way to restore soil fertility.
This time around in Thailand a similar need came up, and farmers and researchers all saw the importance of improving the soil to boost cassava harvests. But even though crotolaria looked like a promising green manure crop, farmers who made their living on small plots of land were not in a position to set aside land for producing seed of a green manure crop. Producing food is a more urgent need and requires all available land. While producing the videos we learned that some farmers grow a legume crop, such as cowpea, peanuts or soya beans in between their cassava.
In the end, we decided not to mention crotolaria in our video: it was still an idea at infant stage, needing more effort to be grounded with farmers. Over time, some farmers may turn into crotolaria seed growers, making the green manure a viable option for cassava farmers, but until that time nurturing the idea in a training video without proper access to seed would only create frustration.
The success of this innovation will depend on more farmers and scientists putting their heads together, and on then allowing the farmers to get used to crotolaria as a new, green manure crop. Researchers are well intentioned when they promote their ideas, but even good ideas need more ground work than most researchers realize.
Some 4,000 years ago, native North Americans of what is now Arkansas, Missouri, Kentucky, Tennessee and surrounding states were domesticating a whole set of crops, most of which you have probably never heard of.
For reasons we do not fully comprehend, when ancient peoples made the transition to agriculture, they never domesticated just one crop by itself. In the first stage of agriculture, first farmers planted and tended wild plants, species which they and their ancestors had been gathering for generations. Within a few centuries, the farmers would select for larger seeds or roots, depending on which part of the plant they ate. This change in form is usually what archaeologists refer to as domestication. By more stringent definitions, domestication is when the plant can no longer reproduce on its own, in the wild, as is the case with maize and potatoes.
The native North Americans domesticated the sunflower (Helianthus annuus), but also the summer squashes (yellow and green varieties) and the acorn squash, all derived from Cucurbita pepo. The other ancient North American crops included the little barley (Hordeum pusillum), goosefoot or lambsquarters (Chenopodium berlandieri), erect knotweed (Phalaris caroliniana) and sumpweed or marsh elder (Iva annua).
Besides the little squashes and the radiant sunflower, the other native crops now survive only as weeds. As North America was one of the last centers of domestication, the crops may still have been robust enough, just wild enough, to reproduce themselves as weeds. As my wife Ana noticed, the sunflower itself is a hardy, fast-growing, weedy-looking plant before it starts to flower (pictured).
Except for the sunflower and the squashes, all the other North American crops were slowly abandoned, probably because they were much less productive than other crops (maize, beans and the larger squashes) which arrived from Mexico, about 100 BC. But the sunflower was valued for food (including oil), dye and even medicine.
Another 1700 years later, the settlers in North America were uninterested in growing the sunflower, although they happily adopted maize, beans and squash. The settlers certainly knew of the sunflower, but they had a diet that was fairly rich in animal fats, especially from pork, and may have found it too tedious to process the oily little sunflower seeds. But many wild species of sunflower still thrived all over the continent.
The sunflower was taken from Mexico to Spain in the 1500s and slowly spread across Europe, largely as an ornamental, eventually reaching as far east as Russia. The sunflower might have ended as an obscure garden flower, if religious taboo had not dealt it a winning hand. During lent, the Russian Orthodox Church banned butter and lard, but sunflower oil was too new to appear on the list of banned oils. The demand for sunflower oil surged, leading V. S. Pustovit of Krasnodar to breed a sunflower with a much larger seed head. Named the Russian Mammoth, this variety was introduced to the USA in 1893. The sunflower slowly gained in importance, but did not become an important crop in the USA until the 1950s
At first the crop was almost entirely exported as oil to Europe, but stiff competition from Europe and Argentina ended that market, and most US sunflower is consumed domestically.
Modern plant breeding saved the sunflower. By 2010 there were 750,000 hectares of sunflower planted in the USA, worth $634 million at the farm gate. About 60% of the crop is used as oil and meal, and 10 to 20% is for snack food and baking. About a quarter of the sunflower harvest is made into birdseed: in 2006 the USA spent $3.35 billion feeding wild birds, roughly equal to the GDP of Fiji.
Under the changing pressure of economic demand, a crop can evolve quickly, from garden flower to Lenten oil to bird food. Once abandoned as a crop in its center of origin, the sunflower is now here to stay, thanks to a little love from Russia and plant breeders.
Selig, Ruth Osterweis 2004 Origins of agriculture in Eastern North America, pp. 258-272. In Ruth Osterweis Selig, Marilyn R. London and P. Ann Kaupp Anthropology Explored (Second Edition). Washington: Smithsonian Books. 473 pp.
Smith, Bruce D. 2014 The domestication of Helianthus annuus L. (sunflower). Vegetation History and Archaeology 23(1):57-74
USDA 2015 Sunflower seed. http://www.ers.usda.gov/topics/crops/soybeans-oil-crops/sunflowerseed.aspx
The red onion variety, Violet de Galmi, originally comes from the village of Galmi, a small community in Niger, about 500 kilometres east of Niamey close to the Nigerian border, where it has been grown for over 100 years. Its pungent flavour and thick bulbs, combined with the vast, informal Hausa trading network, has made this onion popular across West Africa. In fact, onions are Nigerâ€™s second most important export product after uranium, making Niger the largest exporter of onions in the entire region.
While companies sell packaged seed of this variety across the USA, India and Southeast Asia, in the 1990s, a private seed company in Senegal, Tropicasem, a subsidiary of the French seed company Technisem, further bred the Violet de Galmi onion and obtained rights to exclusively market it in nine West African countries. When farmers in Niger found out that a company had claimed exclusive rights to their onion, they were outraged and asked their government to act on their behalf in this case of bio piracy. The farmers won.
But monopolies can go beyond seed.
While thousands of farmers across West Africa grow this variety in the dry season, flooding the market with onions and making prices drop, Violet de Galmi is prone to diseases in the rainy season. This reduces the supply of onions, which become a sought after, precious commodity.
Although Violet de Galmi onions do poorly in the rainy season, there is one place in Niger where they thrive: the valley of Agadez, known as the gateway to the desert, some 500 kilometres north of Galmi. In the rainy season, the trade of red onions in West Africa has been in the hands of the Hausa people, all the way from collection at farm gate to the street hawkers in African towns, thousands of miles away from the Agadez onion fields.
While making a series of farmer training videos on onions in northern Ghana, I was impressed once more with the ingenuity of farmers, trying out seed of new varieties, adjusting their planting calendars and cropping practices to fill a market niche. Salifu, one of the farmers I talked to in Bawku, smiled as he told how he travelled as far as Kumasi, 600 kilometres south, to get seed of a new onion variety.
Seeds of new onion varieties are now making their way into West Africa, and more onions are now being grown in the rainy season, spurred by farmersâ€™ ingenuity and their drive to make the most of high prices. With this expanded supply, the trade monopoly of the harvested onions is also bound to be broken.
Food is too precious a commodity to stay in the hands of a few.
Related farmer training videos:
When you think of Bolivia, peanuts are not the first thing that comes to mind. Yet peanuts are a native crop, domesticated and grown in lowland South America (east of the Andes) for at least 7000 years. The ancient Moche people of Peru even honored the peanut by making gold and silver jewelry of it.
Although peanuts are an oil crop in many countries, in Bolivia the peanut is grown more for food. South Americans have many delightful local dishes based on the peanut, such as peanut soup, peanut drinks, and anticuchosâ€”grilled beef heart covered in a thick peanut sauce.
Despite its popularity in Bolivia, the peanut was neglected by researchers. Now the crop is getting the attention it deserves, although this love comes with its own risks, as I learned recently at the First National Congress and Forum on Peanuts in Bolivia.
There were few peanut specialists when research began in 2004 and no dedicated institution. So Bolivian researchers got together, formed a network, and began building links to specialists in other countries, where peanut research was well established.
In 2007, Bolivia had one of the worldâ€™s lowest peanut yields, barely a ton per hectare. R&D paid off, and now yields are up to 1.6 tons per ha, a remarkable increase in such a short time.
The peanut was first domesticated in the Chaco, the dry lowlands where Bolivia, Paraguay and Argentina meet. Peanuts are well adapted to the short rains followed by a blistering hot dry season. A remarkable genetic diversity emerged from these challenging conditions. Today there are around 100 land races (locally adapted varieties) of peanuts still grown in and near the Bolivian Chaco. The genetic diversity is important for plant breeders around the world who seek improved disease resistance or drought tolerance.
Twelve thousand families grow almost all the peanuts in Bolivia, about 21,000 tons, and perhaps 60% is exported, mostly to Peru. Accounts vary, but only eight to 18 peanut varieties are grown commercially in Bolivia. The other 80 or 90 land races are grown in very small amounts, by isolated people in marginal areas, so most of these land races are at risk of extinction.
Some of this rich genetic diversity is represented in the two major, international peanut gene banks which breeders rely on. The largest collection, of 14,968 accessions, is held by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in Patancheru, India. Most of their accessions are from local land races that arose in Asia. The USDA gene bank in Griffin Georgia, has 9027 accessions, based in part on collections made in Bolivia in the 1990s.
It was encouraging to learn that the Bolivians have their own gene bank with 1050 accessions, potentially representing a greater genetic diversity than the other two gene banks combined. In their typically generous fashion, the Bolivians have placed the data on the internet, in English and Spanish, for public inspection, and possibly for sharing seed www.iniaf.gob.bo and http://184.108.40.206/gringlobal/search.aspx
Gene banks are an invaluable resource but storing seeds is not the same as growing a crop on a farm. Seeds in gene banks don’t last forever and peanuts (and many other crops) need to be planted and harvested every few years to get fresh stock. Over generations of this artificial selection, the seeds are selected for life in the gene bank, not for life on the farm, where it really matters. Itâ€™s crucial to keep any crop growing, in as many varieties as possible, especially in its native homeland.
Research may be improving in Bolivia, but farmersâ€™ concerns are still rooted in profitability. At the Bolivian Peanut Congress, when we split up to attend sessions, almost all of the farmers attended the one on peanut marketing and repeatedly asked for help finding new markets. The sessions on genetics were attended largely by researchers with interests in conservation and breeding.
Farmers who maintain land races are performing a public service that’s taken for granted. Many land races have limited commercial value and could be displaced and lost as higher yielding varieties take over. Commercial growing can really improve rural livelihoods, but only a handful of varieties will become commercial. What will happen to the other 90 varieties grown in very small amounts? There is a real risk is that land races could disappear, causing an irreplaceable loss of genetic diversity.
There is a contradiction here. Agricultural researchers, especially the plant breeders, would like farmers to maintain traditional land races of crops, for future research and development. Yet researchers can offer farmers little or no support to do that. As farmers in remote parts of tropical countries begin to sell more of their crop, these growers are less inclined to grow non-commercial land races.
I began to imagine a system that could preserve endangered crop varieties. Boliviaâ€™s INIAF has already listed the peanut varieties on-line. Through the Internet, and personal contacts, different people could be persuaded to adopt a variety, or a few. They wouldnâ€™t need to grow very many, a few plants each. They could include farmers, hobbyists, gardeners, peri-urban farmers: anyone who loves plants and who wants to share them. This network could share the seeds, and one person would be enough to monitor the flow and population of these precious plants. A moderator could keep track of where each variety was being grown.
There are some precedents for such an idea. For example, in Britain, the Royal Horticultural Society (RHS) maintains a â€śseed schemeâ€ť; members write in, and request packets of seed from the botanical gardens. The members only pay for the postage, and excess seed from the gardens is distributed to people who will raise the plants.
Acknowledgements. The Congress (El Primer Congreso y Foro del ManĂ Boliviano) was moderated by Edwin Mariscal and Juan ArĂ©valo. It was sponsored by the FundaciĂłn Valles, INIAF (Instituto Nacional de InnovaciĂłn Agropecuaria y Forestal) and by the Collaborative Crops Research Program of the McKnight Foundation.
Holbrook, C.C. 2001 â€śStatus of the Arachis Germplasm Collection in the United Statesâ€ť Peanut Science 28:84-89
Williams, D.E. 2001 â€śNew Directions for Collecting and Conserving Peanut Genetic Diversity.â€ť Peanut Science 28:135-140.
Before the discovery of quinoa as a wonder food, in about the year 2000, Andean farmers were starting to abandon it. The brightly colored grains were considered a poor personâ€™s food, a crop to be ashamed of. One of quinoaâ€™s saving graces is that it grows well at altitudes of up to 5000 meters, where little else grows, not even the hardy potato.
As early as 2003 some researchers helped the farmers to realize the value of quinoa, showing them that by adding a bit of fertilizer the traditional intercrop of quinoa and oats yielded much more. (Read related paper Unspoken demands for farm technology).
Even earlier, before anyone thought that quinoa was cool, Bolivian plant breeder Alejando Bonifacio and colleagues had been conserving varieties of the crop. Dr. Bonifacio, born and raised on the Bolivian Altiplano, realized the importance of quinoa when few others did. In 1997, the research agency he worked for collapsed when World Bank support ended, and most agricultural stations were closed.
Researchers often fail to communicate the value of their work with their nearest neighbors, and after the stations closed, local farmers vandalized some, and ate the collections of crop varieties.
The quinoa collection avoided this fate, because Dr. Bonifacio took the 300 or so seed samples home, and saved them in little jars until he found work later with another agency.
When the market for quinoa boomed, there was little demand for the whole diversity held in those 300 jars. The market only wanted â€śroyal quinoa:â€ť large, white sweet grains, not the small ones, or colored ones or the ones with the soapy-tasting saponine.
Quinoaâ€™s success has been good in many ways. It has given impoverished family farmers a new cash crop. Quinoa as a crop has been saved from extinction. Family businesses have grown up around quinoa processing and exporting.
Urban Bolivians have a new appreciation for quinoa and are eating it in cereals, pasta and snacks, made in Bolivia for the local market.
One of my favorites is â€śquinutriĂłnâ€ť, a snack bar made with popped quinoa, honey and Brazil nuts (from lowland Bolivia). The label shows a cartoon armadillo, which Bolivians associate with the high plains, or Altiplano, where most quinoa is grown.
But fame and popularity can also be dangerous. Market preference for just a few varieties has made it harder to preserve the other types of quinoa. This loss of variety within a species is called â€śgenetic erosion.â€ť
Quinoa, like other crops, needs to keep all the genetic diversity it has. Future markets will require new traits, and new varieties will have to be bred for resistance against specific diseases (such as mildew) or for resistance to problems like hail (quite a problem at this high altitude). Keeping this genetic diversity into the future will be a challenge.
Quinoaâ€™s success is also leading to that other form of erosion: lost soil. Instead of fertilizing and caring for a patch of quinoa every ear, farmers find it easier to plow up a fresh field with tractors, grow quinoa, and then abandon the land, leading some to fear that the Altiplano is being turned into a desert for the sake of quinoa.
Dr. Bonifacio and colleagues are now studying ways of conserving soil, including native legumes and grasses, planted with quinoa as live barriers, or as â€śimproved fallowâ€ť to be planted after quinoa is harvested, to allow the soil to regenerate. New technologies, such as tractors, make labor more productive, although, they create new problems that demand research of their own.
Bonifacio, Alejandro, Genaro Aroni, & Milton Villca 2012 CatĂˇlogo EtnobotĂˇnico de la Quinua Real. Cochabamba, Bolivia: Proinpa. http://www.proinpa.org/tic/pdf/Quinua/Variedades%20de%20quinua/pdf33.pdf
Bonifacio,Â Alejandro Flores 2015. Traditional fallows support resilient farming on semi-arid sandy soils. Farming Matters 31(1): 34-36.