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Trying it yourself May 24th, 2020 by

Helping to write a script for a farmer training video on vermiwash triggered my interest in trying it out myself, as I began to wonder if ideas from tropical India could work in temperate Belgium.

As the video explains, vermiwash is the liquid that is collected after water passes through compost made by earthworms. It is rich in plant growth hormones, micro-nutrients like iron and zinc, and major nutrients like nitrogen, phosphorous and potassium. Vermiwash increases the number of beneficial micro-organisms in the soil and helps plants to grow healthy.

After showing the problem of declining soil health due to the overuse of agrochemicals, the video quickly moves on to some powerful, motivational interviews by some local farmers in Tamil Nadu, in southern India.

“When you want to mix vermicompost with the soil, you need large quantities. But vermiwash can be applied directly to plant leaves, so you need less and you can see the effect on plant growth faster. It is also cheaper than compost,” says farmer Sivamoorthi.

Besides the liquid vermiwash, I had also helped another of our Indian partners, WOTR, develop a video on vermicompost, which is solid, and stronger than normal compost . But, I was more attracted to the idea of making vermiwash, as it requires little space and I could easily use it as a foliar spray on my vegetables, berry shrubs and fruit trees.

At the local hardware store, I bought a barrel with a tap at the bottom. The first drafts of the script mentioned that it is best to fill the bottom of the barrel with small stones, so the tap doesn’t get blocked. I did exactly that. In the final version of the video, this part was removed. When I asked Shanmuga Priya, who made this video, she said: “After I talked to farmers it seems no one is doing this, because after three months they empty the barrel, remove the earthworms and then put the compost on their field. Of course, they don’t want stones to be mixed with the compost.”

Indian farmers just use a small piece of mosquito netting or cotton cloth as a filter. Right, that was a good lesson; farmers always find a way to improve any technique they learn from extension staff. I still have the bottom of my barrel filled with pebbles, and so far so good. I will have to make the extra effort of sorting out the stones when setting up a new batch of vermiwash.

The video says to fill the bottom with some 10-15 centimetres of dried leaves, not green ones, which would slow down decomposition. As I had plenty of dried oak leaves, and even though they decompose slowly, I wondered if they would work, but hey, that’s what I have, so that’s what I will try.

Then the video shows how an equal amount of rice straw is added. Instead, I used wheat straw, as I still have plenty of bundles in the attic of our shed.

The next part was also a little tricky. While the video suggested using 5 to 10 kg of decomposed cow dung, I wondered if the dung of my sheep would work just as well. It was a discussion I had had several times with Indian partners, who always say that only cow dung is a useful source of beneficial microorganisms. I asked a friend of mine, who is soil scientist, and still did not get a clear answer to this. Soil scientists are trained more in the physical and chemical properties of soil and are less familiar with its complex biology. But that is food for another blog story.

After adding some water to the barrel, I collected a few handfuls of earthworms from my compost and put them into the barrel. I would soon see if my set up would work or not. While farmers in India can collect vermiwash after just 10 days, I realised that the early days of spring in Belgium are still too cold, so the worms are not that active yet. Six weeks later, though, we happily collected our first litre of brown vermiwash.

After diluting it with ten litres of water, I sprayed the vermiwash on the leaves of my rhubarb as an experiment, before putting it on any other plants. In just a few days the leaves turned a shiny, dark green. The plants looked so healthy, that neighbours even remarked on it and asked what I had given them.

My wife, Marcella, had been rearing vegetable seedlings in a small glass house, and when the time came to transplant them to the garden, she decided to set up a small experiment. One batch of mustard leaf seedlings would be planted straight in the soil, the other batch she would soak the roots of the seedlings for 15 minutes in pure vermiwash. After all, the video shows that this works with rice seedlings, so why not with vegetable seedlings?

And again, the effect was striking: all of the seedlings dipped in the vermiwash took root quickly, while in the other batch only a fraction did.

As Jeff has written in some earlier blogs, the Covid-19 crisis has stopped people from travelling, affecting many farmers (see: Travelling farmers), students (see: A long walk home) and society at large. It has also forced people to creatively use their time. Like many other people, we have been able to spend more time in the garden, and in our case, we were able try out some of the things we learned from farmers in the global South.

As we tried oak leaves, wheat straw and sheep dung instead of the ingredients used by Indian farmers, we found that vermiwash works as well in Flanders as it does in Tamil Nadu. Good training videos inspire people to experiment with new ideas and adapt these to their own conditions. That is the philosophy and approach of Access Agriculture: using video as a global source of inspiration.

Related blogs

Earthworms from India to Bolivia

Encouraging microorganisms that improve the soil

Effective micro-organisms

Friendly germs

Related videos, freely downloadable from www.accessagriculture.org

Vermiwash: an organic tonic for crops

Making a vermicompost bed

Good microbes for plants and soil

Training trees May 10th, 2020 by

Many people are familiar with pruning trees, but on a recent course organised by the association of ecological gardeners (VELT) in Bocholt, Limburg, Belgium, I learned another important trick to shape trees and harvest more fruit. By training trees, you make branches grow in the direction you want. That sounds easy enough, but back home, when trying to apply this to our own fruit trees, I learned once more the importance of understanding the principles, and then adapting them to the local conditions.

Pierre Zanders, the trainer from VELT, explained to us that branches that grow straight upright have tremendous vigour and just continue growing up without giving fruits. The more you can get a branch to grow horizontally, the more fruit it will produce. Young branches that are weighed down by too much fruit can break, so ideally you should aim to train branches to grow at angles between 45 and 60 degrees.

Pierre is such an expert on fruit trees that he is often asked to travel to share his skills. He proudly told us a story about the time he was invited to the USA to train thousands of mature fruit trees. While the job was scheduled to take 6 weeks, Pierre finished the job in just two weeks. In disbelief, the owner of the groves had to accept that Pierre had a much faster way of training branches.

“If you have to train older trees,” Pierre told us, “you don’t need any branch spreaders that cost money. The only thing you need is a very sharp knife. Up in the trees, you find enough wood that can be used as a branch spreader. Prune a stick that is as thick as the twig you want to bend lower. In the stick you have removed from the tree, cut a notch at one end of the stick and then cut the stick to the right length. Fix one end of the stick onto the main tree trunk, and place the end with the notch around the twig you want to bend. Gently push the stick down until the twig reaches the desired angle.” The owner was amazed. This seasoned fruit expert from Belgium had not used any of the commercial branch spreaders the owner had bought to train his trees.

Pierre laughingly provokes us: “why pay money if you can do it much simpler and much faster? Besides, with my technique nobody needs to go back into the orchard a few months later to collect any tree training devices. Over time, the branches will start to grow in the desired direction and the little sticks that I used as branch spreader can stay in the tree or may eventually be blown away by the wind. So, you save money twice.”

During Pierre’s pruning course, we learned that for younger trees it is useful to hang weights to the branches, or to tie strings and use pegs to fix the string down to the soil. After the course I talked to my friend, Johan Hons, an organic farmer, and he kindly gave me a roll of string and taught me a useful knot to loosely tie the string around twigs and branches.

A few days after training my 20 or so fruit trees, I saw in dismay how some of the branches had snapped. “Terrible, how could this happen,” I wondered. “Did I bend them too much?” Taking a closer look at the damage, I noticed some wool on the strings. Apparently, the sheep grazing under my fruit trees had started rubbing themselves against these strings. It was too much for some of the young branches to take.

That was the time I had to come up with my own solution. All my fruit trees have a mesh wire tree shelter guard around their trunk to protect their bark from the sheep. By placing a bamboo stick through the holes at the top of the mesh, I could fix my strings to the bamboo, above reach of the sheep. The two short strings down from the bamboo to the mesh ensure that the bamboo does not snap in half with the pulling forces from the branches.

Farming is about observing what works and what doesn’t work…. If you understand the basic principles of a technology, it is easier to make workable adaptations. Pierre and Johan both gave me good ideas about how to spread branches so they do not grow straight up. But after my sheep undid their good suggestions, I could still invent my own technique, because Pierre had taught me the underlying principle: more horizontal branches produce more flowers and therefore more fruit.

Related videos

Staking and pruning passion fruit

Growing annual crops in cashew orchards

Coffee: stumping & pruning

Strawberry fields once again March 15th, 2020 by

Vea la versión en español a continuación

Like many Bolivians, Diego Ramírez never thought about remaining in the village where he was born, and starting a business on his family’s small farm. As a kid, he loved picking fruit on his grandparents’ small strawberry patch in the village of Ucuchi, and swimming with his friends in a pond fed with spring water, but he had to leave home at a young age to attend high school in the small city of Sacaba, and then he went on to study computer science at the university (UMSS) in the big city of Cochabamba, where he found work after graduation.

Years later, Diego’s dad called his seven children together to tell them that he was selling their grandparents’ farm. It made sense. The grandparents had died, and the land had been idle for about 15 years. Yet, it struck Diego as a tragedy, so he said “I’ll farm it.” Some people thought he was joking. In Ucuchi, people were leaving agriculture, not getting into it. Many had migrated to Bolivia’s eastern lowlands or to foreign countries, so many of the fields in Ucuchi were abandoned. It was not the sort of place that people like Diego normally return to.

When Diego decided to revive his family farm two years ago, he turned to the Internet for inspiration. Although strawberries have been grown for many years in Ucuchi, and they are a profitable crop around Cochabamba, Diego learned of a commercial strawberry farm in Santo Domingo, Santiago, in neighboring Chile, that gave advice and sold plants. Santo Domingo is 2450 km from Cochabamba, but Diego was so serious about strawberries that he went there over a weekend and brought back 500 strawberry plants. Crucially, he also learned about new technologies like drip irrigation, and planting in raised beds covered with plastic sheeting. Encouraged by his new knowledge, he found dealers in Cochabamba who sold drip irrigation equipment and he installed it, along with plastic mulch, a common method in modern strawberry production.

Diego was inclined towards producing strawberries agroecologically, so he contacted the Agrecol Andes Foundation which was then organizing an association of ecological farmers in Sacaba, the small city where Diego lives (half way between the farm and the big city of Cochabamba). In that way Diego became a certified ecological farmer under the SPG PAS (Participatory Guaranty System, Agroecological Farmers of Sacaba).  Diego learned to make his own biol (a fermented solution of cow dung that fertilizes the soil and adds beneficial microbes to it). Now he mixes biol into the drip irrigation tank, fertilizing the strawberries one drop at a time.

Diego also makes his own organic sprays, like sulfur-lime brew and Bordeaux mix. He applies these solutions every two weeks to control powdery mildew, a common fungal disease, thrips (a small insect pest), red mites, and damping off. I was impressed. A lot of people talk about organic sprays, but few make their own. “It’s not that hard,” Diego shrugged, when I asked him where he found the time.

Diego finds the time to do a lot of admirable things. He has a natural flair for marketing and has designed his own packing boxes of thin cardboard, which he had printed in La Paz. His customers receive their fruit in a handsome box, rather than in a plastic bag, where fruit is easily damaged. He sells direct to customers who come to his farm, and at agroecological fairs and in stores that sell ecological products.

Diego still does his day job in the city, while also being active in community politics in Ucuchi. He also tends a small field of potatoes and he is planting fruit trees and prickly pear on the rocky slopes above his strawberry field. Diego has also started a farmers’ association with his neighbors, ten men and ten women, including mature adults and young people who are still in university.

The association members grow various crops, not just strawberries. Diego is teaching them to grow strawberries organically and to use drip irrigation. To encourage people to use these methods he has created his own demonstration plots. He has divided his grandparents’ strawberry field into three areas: one with his modern system, one with local varieties grown the old way on bare soil, with flood irrigation, and a third part with modern varieties grown the old way. The modern varieties do poorly when grown the way that Diego’s grandparents used. And Diego says the old way is too much work, mainly because of the weeding, irrigation, pests and diseases.

Ucuchi is an attractive village in the hills, with electricity, running water, a primary school and a small hospital. It is just off the main highway between Cochabamba and Santa Cruz, an hour from the city of Cochabamba where you can buy or sell almost anything. Partly because of these advantages, some young people are returning to Ucuchi. Organic strawberries are hard to grow, and rare in Bolivia. But a unique product, like organic strawberries, and inspired leadership can help to stem the flow of migration, while showing that there are ways for young people to start a viable business in the countryside. Diego clearly loves being back in his home village, stopping his pickup truck to chat with people passing by on the village lanes. He also brings his own family to the farm on weekends, where he has put a new tile roof on his grandparents’ old adobe farm house.

Agriculture is more than making a profit. It is also about family history, community, and finding work that is satisfying and creative.

Related blog stories

The right way to distribute trees

No land, no water, no problem

To drip or not to drip

Related video

Drip irrigation for tomato


Por Jeff Bentley, 15 de marzo del 2019

Como muchos bolivianos, Diego Ramírez nunca pensó en quedarse en la comunidad donde nació, y empezar un emprendimiento agrícola en las pequeñas chacras de su familia. Diego cuenta que de niño le encantaba recoger fruta en la pequeña parcela de frutillas de sus abuelos en la comunidad de Ucuchi, y nadar con sus amigos en una poza de riego, llena de agua de manantial, pero de joven tuvo que vivir en la ciudad pequeña de Sacaba para estudiar en colegio. Luego se fue a estudiar a la Universidad UMSS, la carrera de ingeniería de sistemas. Culminado los estudios, empezó a trabajar en la ciudad de Cochabamba.

Años más tarde, el padre de Diego llamó a sus siete hijos para decirles que estaba vendiendo el terreno de sus abuelos. Tenía sentido. Los abuelos habían fallecido, y nadie había trabajado la tierra durante unos 15 años. Sin embargo, a Diego le pareció una tragedia, así que dijo: “Yo la voy a trabajar”. Algunos pensaron que era un chiste. En Ucuchi, la gente estaba en plan de dejar la agricultura, no meterse en ella. Preferían emigrar al Oriente de Bolivia y muchos se habían ido del país. Por esta razón muchas de las parcelas están abandonadas. No es el tipo de lugar al que la gente como Diego normalmente regresa.

Cuando Diego decidió revivir su finca familiar ya hace dos años, buscó inspiración en el Internet. Aunque la frutilla es un cultivo ancestral de la comunidad de Ucuchi y muy rentable en Cochabamba, Diego se enteró de una empresa productora de frutillas en Santo Domingo, Santiago, en el vecino país de Chile, que daba consejos y vendía plantas. Santo Domingo está a 2450 km de Cochabamba, pero Diego se tomó tan en serio las frutillas que fue allí un fin de semana y trajo 500 plantas de frutillas. Crucialmente, también aprendió sobre el cultivo tecnificado de frutillas, aplicando el riego por goteo y plantado en camas tapadas con plástico. Movido por sus nuevos conocimientos, buscó distribuidores en Cochabamba que vendían equipos de riego por goteo y los instaló, junto con el mulch plástico, un método común en la producción moderna de fresas.

Diego se inclinó más en la producción agroecológica para producir frutillas, así que se contactó con la Fundación Agrecol Andes que estaba organizando una asociación de productores ecológicos en Sacaba, la pequeña ciudad donde Diego vive, a medio camino entre su terreno y la ciudad grande de Cochabamba. Diego ya tiene certificación de productor ecológico con SPG PAS (Sistema Participativo de Garantía Productores Agroecológicos Sacaba), Diego aprendió a hacer su propio biol (una solución fermentada de estiércol de vaca que fertiliza el suelo mientras añade microbios buenos). Ahora mezcla el biol en el tanque de riego por goteo, fertilizando las frutillas una gota a la vez.

Diego también hace sus propias soluciones orgánicas, como el sulfocálcico y el caldo bordelés. Fumiga estas preparaciones cada dos semanas para controlar el oídium, los thrips (un pequeño insecto), la arañuela roja, y la pudrición de cuello. Me impresionó. Mucha gente habla de aplicaciones orgánicos, pero pocos hacen las suyas. “No es tan difícil”, Diego dijo cuando le pregunté de dónde hallaba el tiempo.

Diego encuentra tiempo para hacer muchas cosas admirables. Tiene un talento natural para el marketing y ha diseñado sus propias cajas de cartón delgado, que ha hecho imprimir en La Paz. Sus clientes reciben la fruta en una bonita caja, en lugar de en una bolsa de plástico, donde la fruta se daña fácilmente. Vende directamente a los clientes que vienen a la misma parcela, en las ferias agroecológicas y en tiendas que comercializan productos ecológicos.

Diego todavía hace su trabajo normal en la ciudad, mientras que también tiene una cartera en la comunidad de Ucuchi. También cultiva una pequeña chacra de papas y está plantando árboles frutales y tunas en las laderas pedregosas arriba de su frutillar. Diego también ha iniciado una asociación de agricultores con sus vecinos, diez hombres y diez mujeres, incluidos adultos mayores y jóvenes que todavía están en la universidad.

Los miembros de la asociación cultivan diversos cultivos, no sólo frutillas. Diego les enseña a cultivar frutillas orgánicamente y a usar el riego por goteo. Para animar a la gente a usar estos métodos, ha creado sus propias parcelas de demostración. Ha dividido el frutillar de sus abuelos en tres áreas: una con su sistema moderno, tecnificado, otra con variedades locales cultivadas al estilo antiguo en suelo desnudo, con riego por inundación, y una tercera parte con variedades modernas cultivadas a la manera antigua. Las variedades modernas no rinden bien cuando se cultivan al estilo de los abuelos. Y Diego dice que la forma antigua es mucho trabajo, principalmente por el desmalezado, el riego y las enfermedades además de las plagas.

Ucuchi es una atractiva comunidad en las faldas del cerro, con electricidad, agua potable, una escuela primaria y un pequeño hospital. Está justo al lado de la carretera principal a Santa Cruz, a una hora de la ciudad de Cochabamba donde se puede comprar o vender casi cualquier cosa. En parte por estas ventajas, algunos jóvenes se están volviendo a la comunidad de Ucuchi. Las frutillas orgánicas son difíciles de cultivar, y son raras en Bolivia. Pero un producto único, como las frutillas orgánicas, y un liderazgo inspirado pueden ayudar a frenar el flujo de la migración, al mismo tiempo de mostrar que hay maneras viables para que los jóvenes empiecen con un emprendimiento personal en el campo. A Diego le encanta estar de vuelta en su comunidad: para su camioneta para charlar con la gente que pasa por los caminos del pueblo. También trae a su propia familia a la finca los fines de semana, donde ha puesto un nuevo techo de tejas en la vieja casa de adobe de sus abuelos.

La agricultura es más que la búsqueda de lucro. También se trata de la tradición familiar, la comunidad y de sentirse realizado con un trabajo satisfactorio y creativo.

Otros blogs que le podrían interesar

La manera correcta de distribuir los árboles

Sin tierra, sin agua, no hay problema

To drip or not to drip

Video sobre el riego por goteo

Riego por goteo para el tomate

American bees March 1st, 2020 by

Vea la versión en español a continuación

When the Spanish conquered the New World, the colonists who followed them brought honey bees. These European bees carried out their own version of the conquest, displacing a wide variety of stingless, native American bees. The native American people had known about these stingless bees and used their honey for centuries. Some, such as the Maya, kept bees for their honey, and many other peoples gathered honey from the wild.

The European honey bee is more aggressive and bigger than the American bees. The African honey bee and the European honey bee are sub-species of the same species, Apis mellifera. The European bee lives in large colonies of some 80,000 individuals, while the native bees live in smaller hives, of 3,000 or so. The American bees have suffered from the loss of forest habitat, and from competition with the European bees, which gather nectar from the same sources that the native bees need.

But the native American bees are making a comeback, as I learned recently on a course taught by two biologists who are experts in native American bees: Marcia Adler Yáñez from the Gabriel René Moreno Museum of Natural History in Bolivia and Oscar “Rupa” Amaya, who is Colombian, but a long-time resident of Brazil.

The American honey bees are a diverse lot, of at least 400 species. Some of the larger ones are as big as European honey bees, while some of the smaller ones are the size of a grain of rice.

The native American bees are gentle (some more than others) and although they do not have stingers, some species will bite to defend their nests. Unlike European bees, which put their honey in combs, native American bees keep their honey and pollen in little wax pots. The American bees have a complex nest structure. The queen lays her eggs in cells in a horizontal comb (unlike the vertical ones the European bees make). The combs of native bees can be disk shaped, or spiral or amorphous. The brood chambers, full of eggs in cells, are surrounded by a wax labyrinth, the involucrum, made to discourage ants and other predators. The pots of honey and pollen are placed around the involucrum.

One species of bee, called señorita, is known from Mexico to Argentina for its fine honey, widely regarded to be an eye ointment. A drop in each eye relieves pain and irritation.

Rupa and Marcia teach their students various techniques to care for native American bees. While keepers of European honey bees have made wooden boxes, or hives, for bee colonies, this was not a common practice for native American bees. In the past 30 years, bee experts in Brazil have adapted bee boxes for native American bees. These bee hives are smaller than those for European bees, but the boxes have thicker walls to keep the bees warm in the winter and cool in the summer.

Rupa and Marcia also teach the use of a simple trap for capturing wild colonies. A plastic soda pop bottle, two-liters or larger, is covered in newspaper (to keep the nest warm) and black plastic (to keep it dark). A tube is placed in a small opening in the side of the bottle, making an inviting door to entice a young queen to set up her nest in the bottle. The bottle is hung on a tree in a forest with bees. In good bee habitat, bees may colonize the bottle within weeks. A skilled beekeeper can later transfer the colony to a proper, wooden hive.

Struggling colonies can be encouraged with an extra food supply. On the bee course, we learned how to make wax pots and fill them with honey or pollen gathered by European honey bees, which you can buy in the store. The native bees will eat the honey and convert the pollen to “bee bread” by using special enzymes. They will also use the wax from the pots to make their own brood cells and food pots.

Bees make wax with an organ in their abdomen, but wax is expensive. The bees need six or eight grams of honey to make a gram of wax. So, putting wax in the nests gives the bees a head-start and lets them start a colony faster.

Brazilian universities have been studying native American bees since the 1950s, and the techniques for keeping these bees are slowly spreading to other Latin American countries. There are also native bees in Australia, where some quite keen beekeepers use bee boxes similar to the Brazilian ones.

Native honey is thin, but sweet and it has a fine flavor. The larger species of native bees can make up to eight liters of honey a year, but the small species can only make about one liter, so this honey is expensive, but it is starting to appear in specialty shops.

We also met a Bolivian forester, Juan Carlos Aruquipa, who works on a project to teach women in the rainforest (the Yungas) to manage native bees, and to sell the honey. This is important, because many of the small flowers of tropical American trees must be pollinated by bees to set seed. And the bees feed on the nectar from the trees. So, without bees there are no trees, and without trees there are no bees.

This is a case where agriculture is moving forward in an imaginative direction, learning to care for wild bees, and to produce valuable honey. Bees need a lot of care, so they are difficult to handle on a massive, corporate scale. But they are perfect for smallholders, especially for women, who find the smaller hives and the gentle bees easier to handle. The little hives are ideal to keep at home. Native American bees are a new, creative direction for agroecological farming.

Scientific names

All bees, American, European, and others, belong to the family Apidae. The European, African and Asian bees with stingers belong to the genus Apis. The stingless, American, Australian and African bees belong to the tribe Meliponini. The large native bees are in the genus Melipona and the small ones are grouped into several genera, including Trigona, Scaptotrigona, Nannotrigona, and Tetratrigonisca. The señorita is Tetragonisca angustula. All of these bees are social. In the Americas and elsewhere there are many other bee species that are solitary, such as bumble bees.

Further reading

I have been interested in Native American bees for a long time, and give a short account of them in:

Bentley, Jeffery, W. and Gonzalo Rodríguez 2001 “Honduran Folk Entomology.” Current Anthropology,42(2):285-300.


Por Jeff Bentley, el primero de marzo del 2020

Cuando los españoles conquistaron el Nuevo Mundo, los colonos que los siguieron trajeron abejas. Estas abejas europeas hicieron su propia versión de la conquista, desplazando a una gran variedad de abejas nativas americanas sin aguijón. Los indígenas conocían a estas abejas nativas y usaron su miel durante siglos. Algunos, como los mayas, guardaban abejas para su miel, y muchos otros pueblos recolectaban miel de la naturaleza.

La abeja europea es más agresiva y más grande que las abejas americanas. La abeja africana y la abeja europea son subespecies de la misma especie, Apis mellifera. La abeja europea vive en grandes colonias de unos 80.000 individuos, mientras que las abejas nativas viven en colmenas más pequeñas, de unos 3.000. Las abejas americanas han sufrido la pérdida de su hábitat forestal, y la competencia con las abejas europeas, que recogen el néctar de las mismas flores que las abejas nativas.

Pero hay nueva esperanza para las abejas nativas americanas, como aprendí recientemente en un curso impartido por dos biólogos expertos en abejas nativas americanas: Marcia Adler Yáñez del Museo de Historia Natural Gabriel René Moreno de Bolivia y Oscar “Rupa” Amaya, que es colombiano pero residente en Brasil desde hace mucho tiempo.

La abeja americana es un grupo muy diverso, de al menos 400 especies. Algunas de las más grandes son del tamaño de las abejas europeas, mientras que algunas de las más chicas son tan pequeñas como un grano de arroz.

Las abejas nativas americanas son relativamente mansos y a pesar de que no tienen aguijones, algunas especies muerden para defender sus nidos. A diferencia de las abejas europeas, que ponen su miel en panales, las abejas nativas americanas guardan su miel y polen en pequeños potes de cera. Las abejas americanas tienen un nido con estructura complicada. La reina pone sus huevos en celdas en un panal horizontal (a diferencia de los verticales que hacen las abejas europeas). Los panales de las abejas nativas pueden tener forma de disco, o de espiral o amorfo. Las celdas de las crías (huevos y larvas), están rodeadas por un laberinto de cera, llamado el involucre, hecho para confundir a las hormigas y otros depredadores. Los potes de miel y polen están fuera y alrededor del involucre.

Una especie de abeja, llamada la señorita, es conocida desde México hasta Argentina por su fina miel, ampliamente considerada como un ungüento para los ojos. Una gota en cada ojo alivia el dolor y la irritación.

Rupa y Marcia enseñan a sus estudiantes varias técnicas para cuidar a las abejas nativas americanas. Mientras que los guardianes de las abejas europeas han hecho cajas de madera, o colmenas, para las colonias de abejas, esta no era una práctica común para las abejas nativas americanas. En los últimos 30 años, los expertos en abejas de Brasil han adaptado colmenas para las abejas nativas. Estas colmenas son más pequeñas que las de las abejas europeas, pero las cajas tienen paredes más gruesas para mantener a las abejas calientes en el invierno y frescas en el verano.

Rupa y Marcia también enseñan el uso de una simple trampa para capturar colonias salvajes. Una botella de refresco de plástico, de dos litros o más grande, se cubre con papel de periódico (para mantener el nido tibio) y plástico negro (para mantenerlo oscuro). Se coloca un tubo en una pequeña apertura en el costado de la botella, haciendo una puerta atractiva para atraer a una joven reina a establecer su nido en la botella. La botella se cuelga de un árbol en un bosque con abejas; en un buen hábitat para las abejas, la botella puede albergar abejas en unas semanas. Un hábil apicultor puede más tarde transferir la colonia a una colmena de madera adecuada.

Las colonias débiles pueden ser fortalecidas con comida extra. En el curso de las abejas nativas, aprendimos a hacer potes de cera y llenarlas con miel o polen recolectado por las abejas europeas, que se puede comprar en la tienda. Las abejas nativas comerán la miel y convertirán el polen en “pan de abeja” usando enzimas especiales. También usarán la cera de los potes para hacer sus propias celdas de cría y ollas de comida.

Las abejas hacen cera con un órgano en su abdomen, pero la cera es cara de hacer. Las abejas necesitan seis u ocho gramos de miel para hacer un gramo de cera. Por lo tanto, poner cera en los nidos ayuda a las abejas a establecer una colonia más fuerte, más rápido.

Las universidades brasileñas han estudiado las abejas nativas americanas desde la década de los 1950, y las técnicas para mantener estas abejas se están extendiendo lentamente a otros países de América Latina. También hay abejas nativas de Australia, donde unos ávidos apicultores hacen cajas parecidas a las brasileñas, para criar abejas.

La miel nativa es menos espesa, pero dulce y tiene un sabor fino. Las especies más grandes de abejas nativas pueden hacer hasta ocho litros de miel al año, pero las especies pequeñas sólo pueden hacer un litro, por lo que esta miel es cara, pero está empezando a aparecer en tiendas especializadas.

También conocimos a un ingeniero forestal boliviano, Juan Carlos Aruquipa, que trabaja en un proyecto para enseñar a las mujeres del bosque lluvioso (los Yungas) a manejar las abejas nativas y vender la miel. Esto es importante, porque muchas de las pequeñas flores de los árboles tropicales americanos deben ser polinizados por las abejas para que formen semilla. Y las abejas se alimentan del néctar de los árboles. Así que sin abejas no hay árboles, y sin árboles no hay abejas.

Este es un caso en el que la agricultura avanza en una dirección imaginativa, aprendiendo a cuidar a las abejas silvestres, y a producir una valiosa miel. Las abejas necesitan cierto cuidado, por lo que son perfectas para los pequeños agricultores, especialmente para las mujeres. Las colmenas más pequeñas y las abejas más mansas son más fáciles de manejar. Sería difícil que las empresas grandes las manejan, pero las colmenas pequeñas son ideales para tener en casa. Las abejas nativas americanas son una nueva y creativa dirección para la agricultura agroecológica.

Nombres científicos

Todas las abejas, americanas y europeas, pertenecen a la familia Apidae. Las abejas europeas, africanas y asiáticas con aguijón pertenecen al género Apis. Las abejas americanas, australianas, y africanas sin aguijón pertenecen a la tribu Meliponini. Las abejas nativas grandes pertenecen al género Melipona y las pequeñas se agrupan en varios géneros, entre ellos Trigona, Scaptotrigona, Nannotrigona y Tetratrigonisca. La señorita es Tetragonisca angustula. Además de estas abejas sociales, en las Américas y en otros continentes hay muchas otras especies que son solitarias, como los abejorros.

Más información

Me han interesado las abejas nativas americanas por mucho tiempo, y doy una breve reseña de ellas en: Bentley, Jeffery, W. and Gonzalo Rodríguez 2001 “Honduran Folk Entomology.” Current Anthropology,42(2):285-300.

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

Vea la versión en español a continuación

We have written earlier in this blog about “Effective Microorganisms®” 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. Abrahán 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.

“Smell the yeast!” Abrahán said. “The yeast are the first microorganisms to respond to the sugar.”

“Not just yeast,” I said. “There must be 10,000 species of microbes in there.” Abrahán 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, Abrahán stressed. Fermentation is without oxygen.

After a month, Abrahán 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 “The Life of the Soil”. 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.

Abrahán’s home also doubles as a small shop, where he sells ácido piroleñoso (liquid smoke distilled during charcoal making—which 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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Por Jeff Bentley

16 de febrero del 2020

Hemos escrito antes en este blog sobre “Microorganismos Efectivos®” 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 descomposición del estiércol. 

Esta semana aprendí cómo uno puede multiplicar sus propios microorganismos, usando un equipo simple y unos pocos ingredientes baratos. El Ing. Abrahán Mujica me mostró a mí y a un pequeño grupo en su curso de agroecología. Recogimos tierra vegetal o sach’a wanu, como decimos en Bolivia, del pie de un molle, en plena ciudad.

En una mesa de plástico, pusimos como 5 kilos de sach’a wanu. Añadimos un kilo de chancaca (azúcar moreno) y un kilo de salvado (cascarilla de cereal rica en proteínas), para alimentar a los microorganismos, y sólo 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!” Abrahán dijo. “La levadura es el primer microorganismo que responde al azúcar y nutrientes”.

“No sólo la levadura”, dije. “Debe haber 10.000 especies de microbios ahí”. Abrahán 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.

Él filtra esta solución a través de un paño ordinario y embotella el líquido 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 descomposición, o aplicado a las plantas como abono filiar. Dijo que está destinado principalmente a los suelos que se han muerto por los plaguicidas, para devolverles la vida.

La casa de Abrahán también funciona como una pequeña tienda, donde vende ácido piroleñoso (humo líquido destilado durante la fabricación de carbón vegetal, que se mezcla con agua y se fumiga sobre los cultivos para controlar los insectos y los hongos de forma natural). También hace jabón potásico (que elabora mezclando sulfato de potasio con aceite de cocina), caldo sulfocálcico, caldo bordelés y otros productos para proteger las plantas sin productos químicos tóxicos.

Aunque Abrahán fabrica los productos que vende, le gusta enseñar a los demás. En su curso de agroecología, enseña a otros sus secretos sobre cómo hacer cada producto. Siempre tendrá mercado, porque habrá mucha gente que no quiere hacer estas mezclas. Y aquellos que hacen la suya también ayudarán a hacer del mundo un lugar mejor, reduciendo el uso de agroquímicos mucho más tóxicos, que Abrahán está convencido son un peligro para los agricultores y consumidores.  

Previamente en nuestro blog

La agricultura con árboles

Effective micro-organisms

Smelling is believing

Videos relacionados

Buenos microbios para plantas y suelo

Better seed for green gram

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