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Encouraging microorganisms that improve the soil February 16th, 2020 by

Vea la versi√≥n en espa√Īol a continuaci√≥n

We have written earlier in this blog about ‚ÄúEffective Microorganisms¬ģ‚ÄĚ or EM, a branded, commercial preparation. In both of those previous stories, people were using EMs in pig pens, to reduce the odor and to quickly turn the manure to a rich, black compost. 

This week I learned how you can culture your own microorganisms, using some simple equipment and a few inexpensive ingredients. Ing. Abrah√°n Mujica showed me and a small group at his agroecology course that you can start by collecting some leaf litter. We gathered the leaves and top soil from the base of two or three molle trees in the city of Cochabamba.

We put some 5 kilos of leaf litter and black soil on a plastic table. We added a kilo of raw sugar and a kilo of bran (rich in proteins), to feed the microorganisms, and just enough water to turn the mix to a paste. It should be just moist enough that it will release a couple of drops when you press it in your hand

As we mixed up the ingredients, a smell like bread yeast soon filled the room.

‚ÄúSmell the yeast!‚ÄĚ Abrah√°n said. ‚ÄúThe yeast are the first microorganisms to respond to the sugar.‚ÄĚ

‚ÄúNot just yeast,‚ÄĚ I said. ‚ÄúThere must be 10,000 species of microbes in there.‚ÄĚ Abrah√°n happily agreed.

We filled a third of a 20-liter bucket with this paste, and covered it with plastic bags, tied on with a rubber tie, to keep out the air. The mix will rot if it is exposed to the air, Abrah√°n stressed. Fermentation is without oxygen.

After a month, Abrah√°n will mix the fermented paste with water in a 200-liter barrel, seal it again for another month, and then drain off the water, which by then will be full of microorganisms.

He filters this solution through an ordinary cloth and bottles the liquid for sale. The label reads ‚ÄúThe Life of the Soil‚ÄĚ. It can be sprayed on the soil to make it healthier, or added to compost to speed up decomposition, or used as fertilizer on plant leaves. He said it is intended mainly for soil that has been killed by pesticides, to bring the soil back to life.

Abrah√°n‚Äôs home also doubles as a small shop, where he sells √°cido pirole√Īoso (liquid smoke distilled during charcoal making‚ÄĒwhich is mixed with water and sprayed onto crops as natural insect and fungus control). He also makes potassium soap (which he makes by mixing potassium sulfate with cooking oil), sulfur-lime blend, Bordeaux mix, and other products for protecting plants without toxic chemicals.

Although Abrahán makes the products he sells, he is happy to teach others. On his agroecology course, he teaches others his trade secrets about how to make each product. There will always be lots of people who don’t want to mix these brews. And those who do make their own will also help to make the world a better place, by reducing the use of toxic pesticides, which Abrahán explains are a danger to farmers and consumers.

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FOMENTANDO MICROORGANISMOS QUE MEJORAN EL SUELO

Por Jeff Bentley

16 de febrero del 2020

Hemos escrito antes en este blog sobre “Microorganismos Efectivos¬ģ” o EM, una marca comercial. Los dos blogs anteriores explican el uso de EMs en camas de cerdos para reducir el olor y ayudar a la descomposici√≥n del esti√©rcol. 

Esta semana aprend√≠ c√≥mo uno puede multiplicar sus propios microorganismos, usando un equipo simple y unos pocos ingredientes baratos. El Ing. Abrah√°n Mujica me mostr√≥ a m√≠ y a un peque√Īo grupo en su curso de agroecolog√≠a. Recogimos tierra vegetal o sach‚Äôa wanu, como decimos en Bolivia, del pie de un molle, en plena ciudad.

En una mesa de pl√°stico, pusimos como 5 kilos de sach‚Äôa wanu. A√Īadimos un kilo de chancaca (az√ļcar moreno) y un kilo de salvado (cascarilla de cereal rica en prote√≠nas), para alimentar a los microorganismos, y s√≥lo el agua suficiente para convertir la mezcla en una pasta, que al apretarla, debe soltar un par de gotas.

Mientras mezclábamos los ingredientes, un olor a levadura de pan llenó el ambiente.

“¬°Sientan la levadura!” Abrah√°n dijo. “La levadura es el primer microorganismo que responde al az√ļcar y nutrientes”.

“No s√≥lo la levadura”, dije. “Debe haber 10.000 especies de microbios ah√≠”. Abrah√°n estuvo plenamente de acuerdo.

Llenamos un tercio de un tacho de plástico de 20 litros con esta pasta y lo tapamos con hojas de plástico, atadas con una liga de goma, para evitar que entre el aire. La mezcla se pudrirá si se expone al aire. Abrahán recalcó que la fermentación es sin oxígeno.

Después de un mes, Abrahán la mezclará con agua en un turril de 200 litros; lo sellará de nuevo por otro mes, y luego drenará el agua, que para entonces estará llena de microorganismos.

√Čl filtra esta soluci√≥n a trav√©s de un pa√Īo ordinario y embotella el l√≠quido para su venta. La etiqueta dice “La vida del suelo”. Puede ser fumigado en el suelo para devolverle vitalidad, o puesto en la abonera para acelerar la descomposici√≥n, o aplicado a las plantas como abono filiar. Dijo que est√° destinado principalmente a los suelos que se han muerto por los plaguicidas, para devolverles la vida.

La casa de Abrah√°n tambi√©n funciona como una peque√Īa tienda, donde vende √°cido pirole√Īoso (humo l√≠quido destilado durante la fabricaci√≥n de carb√≥n vegetal, que se mezcla con agua y se fumiga sobre los cultivos para controlar los insectos y los hongos de forma natural). Tambi√©n hace jab√≥n pot√°sico (que elabora mezclando sulfato de potasio con aceite de cocina), caldo sulfoc√°lcico, caldo bordel√©s y otros productos para proteger las plantas sin productos qu√≠micos t√≥xicos.

Aunque Abrah√°n fabrica los productos que vende, le gusta ense√Īar a los dem√°s. En su curso de agroecolog√≠a, ense√Īa a otros sus secretos sobre c√≥mo hacer cada producto. Siempre tendr√° mercado, porque habr√° mucha gente que no quiere hacer estas mezclas. Y aquellos que hacen la suya tambi√©n ayudar√°n a hacer del mundo un lugar mejor, reduciendo el uso de agroqu√≠micos mucho m√°s t√≥xicos, que Abrah√°n est√° convencido son un peligro para los agricultores y consumidores.  

Previamente en nuestro blog

La agricultura con √°rboles

Effective micro-organisms

Smelling is believing

Videos relacionados

Buenos microbios para plantas y suelo

Better seed for green gram

Farming with trees January 19th, 2020 by

Vea la versi√≥n en espa√Īol a continuaci√≥n.

On a rocky hillside an hour from the city of Cochabamba, agronomist Germán Vargas points out a molle tree. It’s growing from a crack in a sandstone boulder with little or no soil. Native trees are well adapted to such conditions and don’t need much to survive, Germán observes.

Molle can be cut for good firewood, but it also casts an inviting shade, with a thick carpet of fallen leaves. Trees grown on farms also have multiple uses. Some have deep roots that bring up nutrients from beneath the top soil. Even in places like Cochabamba, with a long dry season, many trees stay green all year round. The trees have found water to keep their leaves moist, despite the bone-dry subsoil. Germ√°n explains that farming with trees, or agroforestry, mimics natural forests, where rich soils are created without irrigation or fertilizer.

Four years ago, Germ√°n and two colleagues bought some land to put their ideas on agroforestry into practice. They now have 1500 apple trees in a 4-hectare orchard, on a former onion farm, where the intensive use of chemical fertilizers and pesticides had depleted the soil of nutrients.

Germ√°n and his friends bought some apple seedlings from a local nursery. They chose improved Brazilian apple varieties, such as Eva and Princesa, which do well in the highland tropics of South America, where it can get cool, but does not freeze.

Germ√°n and his colleagues plant a few more trees every year. They start each new planting by digging a trench every two to three meters (depending on the slope), to let water infiltrate the soil. They throw the soil just uphill of the trench to create a barrier, slowing down the runoff of water and trapping sediment.

Germ√°n is careful not to scrape the soil surface with hand tools; the top soil is so thin that rough handling could remove it all. They add a little compost to the soil, mimicking a natural forest, where fallen leaves and trees rot and release nutrients back into the soil. However, forests also have an understory, so potatoes, maize, lettuce, amaranth, rye and other plants are sown between the trees. After planting the vegetables, a straw mulch keeps down the weeds.

Other trees are planted among the apples, including natives like molle and exotic species, which are monitored to see if they can make a positive contribution. Germ√°n brought seed of the chachafruto tree from Colombia, for example. The plant is adapting well. When the only date palm in Cochabamba, another non-native species, dropped a cluster of dates in a city park, Germ√°n salvaged the seed and planted some on the farm. The non-fruit trees make useful leaf litter, adding nutrients and helping to keep the soil moist.

The apples were remarkably free of mildew, mites, fruit flies and other common pests, but even if they were to appear, Germ√°n avoids using pesticides. The team managing the orchard makes a spray with cow manure, raw sugar, bone meal, sulfur, ash and lime. Reasoning that all stone has mineral nutrients, they add a little ‚Äúrock flour,‚ÄĚ made by grinding a soft, local, sedimentary stone (shale). A culture of beneficial microorganisms is added to ferment the mix in sealed drums. The agroforesters culture the microorganisms themselves, but they get the starting culture in the local forest, bringing in a few handfuls of fallen leaves that have started to decompose. The sulfur and the lime come from the farm supply store. This sulfur blend is sprayed about 5 times a year on the trees, and it seems to be working, since the apples have almost no pests, except for birds, and the annual plants are thriving.

This innovative agroforestry system needs regular attention and it is obviously a lot of work, especially at first, because it is established by hand, without machinery. Some of the radishes have gone to seed, and in a few beds the weeds are lush and healthy, waiting to be cut down for the next vegetable crop.

Farmers can learn from forests to make better use of water, conserve the soil and manage pest and disease naturally, thanks to the diversity of plants. Farming with trees can yield a good harvest of fruits and vegetables, while building and sustaining soils.

Related blog stories

Apple futures

What counts in agroecology

Gardening against all odds

Enlightened agroecology

Watch some related videos

SLM02 Fanya juu terraces shows how to make infiltration trenches, that form terraces.

SLM03 Grevillea agroforestry

SLM08 Parkland agroforestry

Scientific names

The molle tree is Schinus molle

The chachafruto tree (widespread in South America) is Erythrina edulis

Note

Sulfur deficiency is a problem in apples. The symptoms are similar to nitrogen deficiency, including pale leaves. Sulfur deficiency can be corrected by sprays (Westwood 1993: 200-201).

Westwood, Melvin Neil 1993 Temperate-Zone Pomology: Physiology and Culture. Third edition. Portland, Oregon: Timber Press.

Acknowledgements

Thanks to Germán Vargas, Marcelina Alarcón and Freddy Vargas, the agroforesters. Germán is the executive administrator of the NGO Agroecología y Fe.

LA AGRICULTURA CON √ĀRBOLES

En una ladera rocosa a una hora de la ciudad de Cochabamba, el ingeniero agr√≥nomo Germ√°n Vargas se√Īala un molle. Crece en una grieta de una roca arenisca, con poca o ninguna tierra. Los √°rboles nativos est√°n bien adaptados a estas condiciones y no necesitan mucho para sobrevivir, observa Germ√°n.

El molle hace buena le√Īa, pero tambi√©n da una rica sombra, con una gruesa alfombra de hojas ca√≠das. Los √°rboles en el agro tambi√©n tienen m√ļltiples usos. Algunos tienen ra√≠ces profundas que traen los nutrientes de debajo del suelo. Incluso en lugares como Cochabamba, con una larga √©poca seca, muchos √°rboles se mantienen verdes durante todo el a√Īo. Los √°rboles han encontrado agua para mantener sus hojas h√ļmedas, a pesar del subsuelo seco. Germ√°n explica que la agricultura con √°rboles, o la agroforester√≠a, imita a los bosques naturales, donde se crean suelos ricos sin irrigaci√≥n ni fertilizantes.

Hace cuatro a√Īos, Germ√°n y dos colegas compraron un terreno para poner en pr√°ctica sus ideas sobre agroforester√≠a. Ahora tienen 1500 manzanos en un huerto de 4 hect√°reas, en una antigua granja de cebollas, donde el uso intensivo de fertilizantes qu√≠micos y pesticidas hab√≠a agotado los nutrientes del suelo.

Germ√°n y sus compa√Īeros compraron algunos plantines de manzana en un vivero local. Escogieron variedades mejoradas de manzanos brasile√Īos, como Eva y Princesa, que se desarrollan bien en los tr√≥picos de las alturas de Am√©rica del Sur, donde puede hacer fr√≠o, pero no se congela.

Germ√°n y sus colegas plantan unos pocos √°rboles m√°s cada a√Īo. Comienzan cada nueva plantaci√≥n cavando una zanja cada dos o tres metros (dependiendo de la pendiente), para dejar que el agua se infiltre en el suelo. Lanzan la tierra justo cuesta arriba de la zanja para crear una barrera, frenando el escurrimiento de agua y atrapando el sedimento.

Germ√°n tiene cuidado de no raspar la superficie del suelo con herramientas; el suelo negro de la superficie es tan delgado que sin tener cuidado ser√≠a posible quitarlo todo. A√Īaden un poco de abono al suelo, imitando un bosque natural, donde las hojas y los √°rboles ca√≠dos se pudren y liberan nutrientes de nuevo al suelo. Sin embargo, los bosques tambi√©n tienen un sotobosque, por lo que las papas, el ma√≠z, la lechuga, el amaranto, el centeno y otras plantas se siembran entre los √°rboles. Despu√©s de plantar las verduras, un mantillo de paja mantiene las malas hierbas.

Entre las manzanas se plantan otros √°rboles, incluyendo especies nativas como el molle y especies ex√≥ticas, que son monitoreadas para ver si pueden hacer una contribuci√≥n positiva. Germ√°n trajo semillas del √°rbol de chachafruto de Colombia, por ejemplo. La planta se est√° adaptando bien. Cuando la √ļnica palmera datilera de Cochabamba, otra especie no nativa, dej√≥ caer un racimo de d√°tiles en un parque de la ciudad, Germ√°n recuper√≥ algunas semillas y las plant√≥ en la finca. Los √°rboles no frutales botan hojas, a√Īadiendo nutrientes y ayudando a mantener el suelo h√ļmedo.

Las manzanas estaban notablemente libres de mildiu, √°caros, moscas de la fruta y otras plagas comunes, pero incluso si aparecieran, Germ√°n evita el uso de pesticidas. El equipo que maneja el huerto fumiga con un biol hecho de esti√©rcol de vaca, chancaca, huesos molidos, azufre, cenizas y cal. Razonando que toda piedra tiene nutrientes minerales, le agregan un poco de “harina de roca”, hecha al moler una piedra sedimentaria suave, local (lutita). Para fermentar la mezcla, agregan un cultivo de microorganismos buenos a los tambores sellados. Los agroforestales cultivan sus propios microorganismos, pero obtienen la cultura inicial en el bosque local, trayendo unos pocos pu√Īados de hojas ca√≠das que han comenzado a descomponerse. Compran el azufre y la cal en la tienda agropecuaria. Fumigan el biol con azufre unas 5 veces al a√Īo en los √°rboles, y parece que funciona, ya que las manzanas casi no tienen plagas, excepto los p√°jaros, y las plantas anuales est√°n prosperando.

Este innovador sistema agroforestal necesita atención regular y obviamente es mucho trabajo, especialmente al principio, porque se establece a mano, sin maquinaria. Algunos de los rábanos han empezado a echar semilla, y en algunas camas las hierbas silvestres son exuberantes y saludables, esperando ser cortadas para el siguiente cultivo de hortalizas.

Los agricultores pueden aprender de los bosques a hacer un mejor uso del agua, conservar el suelo y manejar las plagas y enfermedades de forma natural, gracias a la diversidad de plantas. La agricultura con √°rboles puede producir una buena cosecha de frutas y verduras, a la vez que construye y mantiene los suelos.

Otros blogs sobre el tema

Manzanos del futuro

Lo que cuenta en la agroecología

Un mejor futuro con jardines

La luz de la agroecología

Videos relacionados

SLM02 Terrazas fanya juu muestra cómo hacer zanjas de infiltración, que forman terrazas.

SLM03 Agroforestería con grevillea

SLM08 Agroforestería del bosque ralo

Nombres científicos

El molle es Schinus molle

El chachafruto (árbol bien distribuido en Sudamérica) es Erythrina edulis

Nota

La deficiencia de azufre es un problema com√ļn en los manzanos. Los s√≠ntomas son parecidos a los de la deficiencia de nitr√≥geno, incluso las hojas p√°lidas. La deficiencia de azufre puede ser corregida con fumigaciones (Westwood 1993: 200-201).

Westwood, Melvin Neil 1993 Temperate-Zone Pomology: Physiology and Culture. Third edition. Portland, Oregon: Timber Press.

Agradecimientos

Gracias a Germán Vargas, Marcelina Alarcón y Freddy Vargas, por su ejemplo con la agroforestería. Germán es el administrador ejecutivo de la ONG Agroecología y Fe.

The old cat and mouse game November 24th, 2019 by

Did ancient farmers domesticate cats to catch mice? If so, this would have been a classic example of biological pest control, but so far the evidence is largely circumstantial.

Evidence for domestication of a crop or animal is generally based on two lines of study, genetic and archaeological. When both types of research are well and thoroughly done, they tend to support each other. In the case of cats, we still have a ways to go for archaeology to match the genetics.

Oxford zoologist Carlos Driscoll and colleagues explain that there are five living sub-species of wildcats, from Europe to Africa to Asia. Modern domesticated cats are genetically quite close to the Near Eastern wild cat; they even share the same mitochondrial DNA. Based on genetic evidence Driscoll suggests that cats were domesticated some 10,000 years ago in the Fertile Crescent (modern Turkey and Iraq) about the same time that grain farming and livestock tending started there.

Cat domestication at the dawn of agriculture would suggest that early farmers appreciated the wildcats as mousers. With early farming came stores of grain, attracting mice.  

Yet cats are a poor candidate for domestication, because they are obligate carnivores and solitary. Driscoll agrees with archaeologists that ancient farmers did actively domesticate herd animals (sheep, goats and cattle), i.e. penning them, culling undesired individuals, selecting for smaller, tamer, food animals. But Driscoll says that cats were different: cats domesticated themselves‚ÄĒmuch like dogs, pigs and even swallows, rats and mice. Cats were attracted to the food scraps, the fat mice, and the warm nest sites to be found on small farms. Cats moved in with the farmers, who tolerated them.

This is of course just a hypothesis, consistent with (but not demonstrated by) the genetic evidence and there is little archaeology to back it up.

Some of the earliest cat bones from an archaeological site are much later and far from the Fertile Crescent, in China, from a 6000-year-old site where Yaowu Hu of the Chinese Academy of Sciences and colleagues found cat bones tossed into the refuse pits of Quanhucun village. One cat bone was from an old individual, suggesting that the individual had been cared for by farmers.

Ancient farmers quite possibly gave kittens to their neighbors, spreading cats of Near Eastern extraction from Ireland to China to South Africa. Cats then reached the Americas with the Spanish Conquest.

Cats are not universally appreciated as mice killers. Pest control advice books encourage homeowners to get traps to control mice, writing that cats bring in fleas and disease, kill songbirds, and that their effectiveness as biological control agents of mice is not scientifically documented.

My own experience suggests that if you bring a kitten into a mice-infested household, you will have no rodents left in the house or garden by the time the cat is half grown.

Modern smallholders I have met from Portugal to Honduras to Bolivia do keep cats expressly to control mice, and the cats are often treated with a respectful distance, not petted, not given medical attention and not fed (although they may be allowed to eat scraps). Even today, in the large, informal market of Cochabamba, La Cancha, kittens are sold in little wire cages, along with chickens, guinea pigs and other small farm animals.

To get back to the dawn of agriculture, if ancient farmers perceived cats as mice-killers, that may have been enough to earn cats a space to live on farms, where they could domesticate themselves.

Further reading

Driscoll, Carlos A., Marilyn Menotti-Raymond, Alfred L. Roca, Karsten Hupe, Warren E. Johnson, Eli Geffen, Eric H. Harley, Miguel Delibes, Dominique Pontier, Andrew C. Kitchener, Nobuyuki Yamaguchi, Stephen J. O‚ÄôBrien, and David W. Macdonald. 2007 ‚ÄúThe Near Eastern origin of cat domestication.‚ÄĚ Science 317(5837): 519-523.

Driscoll, Carlos A., David W. Macdonald, and Stephen J. O’Brien. 2009 “From wild animals to domestic pets, an evolutionary view of domestication.” Proceedings of the National Academy of Sciences 106. Supplement 1: 9971-9978.

Hu, Yaowu, Songmei Hu, Weilin Wang, Xiaohong Wu, Fiona B. Marshall, Xianglong Chen, Liangliang Hou, and Changsui Wang. 2014 ‚ÄúEarliest evidence for commensal processes of cat domestication.‚ÄĚ Proceedings of the National Academy of Sciences 111(1): 116-120.

The problem with water hyacinth November 17th, 2019 by

The Pantanal wetland, shared by Bolivia and Brazil, is the size of a small sea. In the Pantanal it rains for six months, followed by a half year drought. During the rainy season the rivers overflow their banks, creating a seemingly endless sheet of shallow water reaching to the horizon. In the dry season the water retreats to the river courses. There are few trees in the Pantanal, but there are dense stands of a delicate-looking purple flower, the water hyacinth.

In the twentieth century, gardeners innocently spread the water hyacinth to Asia, Africa and elsewhere. Water hyacinth has striking blue flowers and was used to adorn ornamental fountains. But it escaped and was soon clogging lakes, ponds and municipal water supplies.

Water hyacinth is such a survivor that you can drain ponds, let the plants dry out and burn them ‚Äď then watch them grow again when the pond is refilled. It‚Äôs not surprising that control options are limited, particularly in open water, such as lakes and rivers.

The plants can be hand removed, by people willing to do heavy labor in the mud, cutting and dragging water hyacinth to the shore. Even this drudgery only works if you repeat it every year.

When the water hyacinth is removed, people tend to leave it in heaps at the edge of the water, where it is unsightly and gets in the way.

I recently saw another solution for water hyacinth in Benin, in West Africa. At Songhai, a training center in Porto Novo, they harvest water hyacinth, chop it, mix it with manure and use it to make methane (biogas) for cooking. Songhai also keeps a large tank of methane to run an electrical generator when the power is out.

Making biogas isn’t for everyone, as we saw in a previous blog. The Moreno family in Peru has trained people for years to make biogas from guinea pig manure, but few if any of the trainees later made biogas at home. For this to happen you need to buy equipment, provide labor, and pay close attention to managing the microorganisms that ferment the organic matter and give off the gas.

I liked the Songhai method because they don‚Äôt just remove the water hyacinth. They treat it like raw material and they make something with it.  But I wondered if using it to make biogas was profitable. A more detailed study is needed to gauge its potential to make money. The Songhai solution has one key advantage: the water hyacinth does not need to be dried, a plus because the big heaps of flesh plants hold retain a lot of water.

Water hyacinth is a water thief in some of the thirstier parts of the world. Finding uses for it may help to defray the costs of weeding it out.

Related blog story

The guinea pig solution

The juice mobile

Harsh and healthy

Floating vegetable gardens

Videos

Learn how to use water hyacinth to make a floating garden

Floating vegetable gardens

Learn how to make biogas

Zero-grazing and biogas

Scientific name

Water hyacinth is Eichhornia crassipes.

Poisoning our friends October 20th, 2019 by

Except for entomologists, no one knows more about insects than farmers. Wherever researchers have bothered to talk to smallholders about insects, whether in Honduras, Nepal, or among the Dogon of Mali, or the Kayap√≥ of the Brazilian rainforest, we see that rural people know the names of hundreds of insects and spiders. This is especially true of critters that are conspicuous (such as the big ones that are active during the day) or those that make themselves important, e.g. by eating crops.  

However, a recent, quantitative global literature review by Kris Wyckhuys and colleagues confirms that farmers know little about beneficial insects, especially in industrialized countries. As we saw in this blog last week, it is fairly easy to notice toads and other relatively large animals eating insect pests. Many farmers know that birds, frogs and cats are natural enemies of pests. Yet Wyckhuys found that worldwide, farmers mention on average only 0.9 insects or spiders that help to control insect pests.

Farmers can have sophisticated knowledge of certain, individual insect species. For example, Paul Van Mele and colleagues have described Vietnamese farmers who used weaver ants to control pests in fruit orchards. Such cases are, however, disappointingly rare. Weaver ants are big, diurnal, and easy to spot in their treehouse nests sewn together from leaves. Farmers were also motivated to watch weaver ants because they prey on insects like fruit flies in high-value orchards.  Most other natural enemies of insect pests, ‚Äúfarmers‚Äô friends‚ÄĚ go unnoticed. Hardly any rural people know about other common natural enemies of pests, such as parasitic wasps, insect-eating fungi and nematodes.

Farmers tend to use more pesticides in cash crops, and know fewer natural enemies for these crops, than in food staples. The use of pesticides is growing worldwide, while the pest problems are as bad as ever. Farmers are born experimenters, but to find alternative to pesticides, they need to know more about the natural enemies of insect pests.

Wyckhuys suggests that some of the world’s half trillion-dollar subsidies for agriculture could be devoted to agro-ecological education. Farmers will never find alternatives to pesticides unless they understand that most insects are beneficial. As farmers use insecticides to kill pests, they unwittingly poison their friends, the insects that eat and kill those pests.

Further reading

Van Mele, P 2008 ‚ÄúThe importance of ecological and socio-technological literacy in R&D priority setting: the case of a fruit innovation system in Guinea, West Africa.‚ÄĚ International Journal of Agricultural Sustainability 6: 183‚Äď94.

Wyckhuys, K.A.G., K.L. Heong, F. Sanchez-Bayo, F.J.J.A. Bianchi, J.G. Lundgren and J.W. Bentley 2019 ‚ÄúEcological Illiteracy Can Deepen Farmers‚Äô Pesticide Dependency.‚ÄĚ Environmental Research Letters 14: 093004

Related videos

Promoting weaver ants in your orchard

Weaver ants against fruit flies

The wasp that protects our crops

Killing fall armyworms naturally

See also the many other farmer learning videos about Integrated Pest Management on www.accessagriculture.org.

Related blog stories

Toads for watermelon

Battling the armyworm

Biological pest control in the Galapagos forest

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