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Municipal compost: Teaching city governments December 27th, 2020 by

Vea la versión en español a continuación

Much of farm produce ends up in city landfills, but with a little work and some smart ideas, towns can recycle their organic waste, as I saw recently in Tiquipaya, a small city in metropolitan Cochabamba, Bolivia.

For over ten years, Tiquipaya’s municipal composter has turned some of the city’s trash into the best organic fertilizer. Ing. Denis Sánchez, who runs the city composter, obviously loves his work and is happy to show groups around the tidy (and fly-free) operation.

The first stop is reception, where garbage trucks and cooperating citizens dump off refuse: the garden trimmings from the city’s parks, wilted flowers from the cemetery, waste from the market, and trash from nearly half of the municipality’s households. At reception, Denis’ crew does their most tedious task, separating the plastic from the organic. Cooked food waste is a nuisance because it rots quickly and has “very bad microbes,” as Denis puts it.

Denis is certain that the compost picks up good microbes from its surroundings. Compost’s good microbes smell good and the only slightly bad odor is from the fresh garbage in the reception area. The composter is only four blocks from the town square, so the city government would not tolerate any bad smells. In reception, the fresh, “green” refuse is mixed about half and half with “brown” waste, such as dried tree leaves pruned from city parks. Mixing was easier when the compost plant had a chipping machine that would chop up all the tree branches. The machine broke down a few years ago, so now the crew occasionally gets a caterpillar to come in and roll over the tree branches to break them up. The small bits go into the compost and the big pieces are sold as firewood.

From reception, the blend of brown and green trash goes to the “forced air” section. Compost needs air, which can be provided by turning over the pile, but that’s a lot of work. At the Tiquipaya plant, perforated hoses force air up into each 40-ton pile of compost. The crew waters the compost once a week, for seven weeks, and during that time they do turn it one time, for an even decomposition.

After seven weeks the compost is taken to mature, like a fine wine. It is heaped up and every week it is watered, and also turned with a little front-end loader. The aged compost is then sifted in a rotating drum to remove any big pieces. The resulting fine compost is then sold to the public.  The municipality also fertilizes Tiquipaya’s city parks with the compost, so they do not have to buy any fertilizer. The city also uses the compost as potting soil to grow ornamental plants.

Of course, it’s not all easy. One limitation is education. The municipal market has separate bins for organic and plastic garbage, but most patrons toss all their trash into one can or the other. Three of the city’s eight garbage routes send a truck one day a week to collect organic trash from households. On each ride, Denis sends a member of staff along to remind residents to leave out their plastics and cooked food waste. It’s a constant job to educate the public, so sometimes the municipality rewards cooperating families with plants.

A second limitation is labor. Even with some clever machines, the hard-working staff (three full-time and four part-time, besides Denis) can process about 5.5 tons of trash per day, of the 40 tons that Tiquipaya produces. The city could compost 20 tons of rubbish, with a bit more space, additional workers and investment.

Denis says that it costs 312 Bs. ($44) to make a cubic meter of compost, which he sells for 120 Bs. ($17), a loss he has to accept because “no one would pay its true cost.”

The plant was created with an investment of 1,734,000 Bs. ($246,000) and has an annual labor cost of 185,000 Bs. ($26,000), financed by the municipal government. The compost plant has had financial and technical support from Catalonia and Japan.

The crew seems to be enjoying their morning at the plant. It is light, active work in the glorious Andean sunshine with friendly colleagues.

Tiquipaya’s large neighbor, the city of Cochabamba, has a wretched problem with its landfill, now full and rising like a tower while the surrounding residents often protest by blockading out the garbage trucks, forcing the trash to pile up in city streets.

Cities have to invest to properly dispose of their garbage. People who make trash (including the plastics industry) can be charged for its disposal. The public needs to be taught how to buy food with less plastic wrapping and how to recycle green waste at home. The good news is that cities can recycle much of their rubbish, selling the plastics, and producing compost to improve the soil and replace chemical fertilizer.

Denis thinks of his plant as a school, where others can learn. In fact, several small cities (Sacaba, Vinto, Villazón, and some in the valleys of Santa Cruz) have started similar plants on the Tiquipaya model. Denis is proud to show his work to others.

With some enlightened investment, a city can turn its garbage into useful products and green jobs while avoiding unsustainable landfills, which simply bury the nutrients that farmers have won from the soil.

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Smelling is believing

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Good microbes for plants and soil

Compost from rice straw

Composting to beat striga

COMPOST MUNICIPAL: UNA ESCUELA PARA LAS ALCALDÍAS

Por Jeff Bentley

27 de diciembre del 2020

Mucha de la producción agrícola termina en los rellenos sanitarios urbanos, pero con un poco de esfuerzo y unas ideas claras, los municipios pueden reciclar su basura orgánica, como vi hace poco en Tiquipaya, una pequeña ciudad en el eje metropolitano de Cochabamba, Bolivia.

Hace más de diez años, la compostera municipal de Tiquipaya ha convertido parte de su basura en un excelente fertilizante orgánico. El Ing. Denis Sánchez dirige la compostera, y obviamente le encanta su trabajo y el mostrar su planta bien ordenada (y libre de moscas) a grupos de ciudadanos.

En la primera parada, la recepción, los camiones basureros y algunos vecinos colaboradores, dejan su basura, las podas del ornato público, flores marchitadas del cementerio, basura del mercado y de casi la mitad de las familias del municipio. En recepción, los trabajadores realizan lo más tedioso, separando los plásticos de los orgánicos. Los restos de la comida son una molestia porque se pudren rápidamente y tienen “algunos microbios muy malos,” como Denis explica.

Denis afirma que el compost adquiere buenos microbios de su entorno. Los microbios buenos huelen bien y el único olor un poco desagradable viene de la basura fresca en recepción. La planta está apenas a cuatro cuadras de la plaza principal, y la alcaldía no toleraría ningún mal olor. En recepción, la basura fresca, la “verde”, se llena mitad-mitad con los desechos “marrones” tales como la hojarasca de los parques urbanos. El mezclarlo era más fácil cuando la compostera tenía una máquina que picaba todas las ramas. La máquina se descompuso hace algunos años, y ahora de vez en cuando traen una oruga que pisotea las ramas para quebrarlas. Los pedazos pequeños entran al compost y las piezas grandes se venden como leña.

Después de la recepción, la mezcla de basura verde y marrón pasa a la sección de “aireación forzada”. El compost necesita aire, que se puede proveer con el volteo, pero es mucho trabajo. En la compostera de Tiquipaya, usan tubería perforada para empujar el aire a cada pila de 40 toneladas de compost. Riegan las pilas una vez a la semana, durante siete semanas, y durante ese tiempo las voltean una vez, para lograr una descomposición pareja.

A las siete semanas, llevan el compost a madurarse, como un vino fino. Hacen montones de compost que se riegan y se voltean cada semana con una máquina mini cargadora. El compost madurado es cernido en un dron rotatorio para sacar cualquier objeto grande. El compost fino se vende al público. La alcaldía fertiliza los parques de Tiquipaya con el compost, así que no tienen que comprar fertilizante. Además, usan el compost como sustrato para producir plantas ornamentales.

Claro que cuesta trabajo. Una limitación es la educación. El mercado municipal tiene basureros separados para plásticos y orgánicos, aunque los usuarios a veces mezclan todo. Tres de las ocho rutas del carro basurero recogen solo residuos orgánicos un día de la semana, y cada vez, Denis manda un funcionario de la planta para hacerle recuerdo a la gente que no incluyan sus plásticos ni sus restos de comida. La educación pública es un esfuerzo constante. De vez en cuando regalan plantas para premiar a los buenos vecinos.

Una segunda limitante es la mano de obra. Aun con maquinaria, el esmerado personal (tres a tiempo completo y cuatro a tiempo parcial, además del Ing. Denis) logra procesar unas 5.5 toneladas de basura por día, de las 40 toneladas que Tiquipaya produce. Con un poco más de espacio, personal, e inversión podrían compostar 20 toneladas.

Denis cuenta que cuesta 312 Bs. ($44) hacer un metro cúbico de compost, lo cual vende por 120 Bs. ($17), una pérdida que se acepta porque “nadie pagaría su costo real.”

La planta se creó con una inversión de 1,734,000 Bs. ($246,000) y tiene un costo anual de mano de obra de 185,000 Bs. ($26,000), financiada por la alcaldía. La compostera ha tenido apoyo financiero y técnico de Cataluña y del Japón.

Parece que los trabajadores municipales disfrutan de su trabajo en la planta. Es trabajo físico, pero liviano al aire libre mientras que permite la charla entre colegas.

La ciudad vecina a Tiquipaya, Cochabamba, tiene un problema severo con su relleno sanitario, que ahora está lleno y crece como una torre, mientras los vecinos frecuentemente protestan, bloqueando la entrada a los camiones basureros, hasta que la basura se deja en montículos por toda la ciudad.

Las ciudades tienen que invertir para deshacerse correctamente de su basura. Se puede cobrar impuestos a la gente que genera la basura, incluso a las industrias de los plásticos. Hay que enseñar al público a comprar comida con menos envases plásticos, y cómo reciclar la basura verde en casa. La buena noticia es que las ciudades pueden reciclar gran parte su basura, vendiendo los plásticos y produciendo compost para mejorar el suelo y para reemplazar a los fertilizantes químicos.

Denis piensa en su planta como una escuela, donde otros pueden aprender. De hecho, varias ciudades pequeñas (Sacaba, Vinto, Villazón, y algunas en los valles de Santa Cruz), han construido plantas similares, usando el modelo de Tiquipaya. Denis está dispuesto a compartir sus conocimientos con otra gente interesada, sintiendo mucho orgullo por lo logrado.

Con un poco de inversión inteligente, una ciudad puede convertir su basura en productos útiles e ítems de trabajo verde, mientras evita los rellenos no sostenibles, que simplemente entierran los nutrientes ganados con tanto esfuerzo por la producción agrícola.

Previos relatos en nuestro blog

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Smelling is believing

Offbeat urban fertilizer

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Compost from rice straw

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Living Soil: A film review December 20th, 2020 by

Written with Paul Van Mele

In the opening scenes of the film, “Living Soil,” we see the Dust Bowl: the devastated farmland of the 1930s in the southern plains of the USA. Thirty to fifty years of plowing had destroyed the soil, and in times of drought, it drifted like snow.

As the rest of this one-hour film shows, there is now some room for optimism. Nebraska farmer Keith Berns starts by telling us that most people don’t understand the soil, not even farmers. But this is changing as more and more farmers, large and small, organic and conventional, begin to pay attention to soil health, and to the beneficial microbes that add fertility to the soil. Plants produce carbon, and exchange it with fungi and bacteria for nutrients.

Mimo Davis and Miranda Duschack have a one-acre city farm in Saint Louis, Missouri. The plot used to be covered in houses, and it was a jumble of brick and clay when the urban farmers took it over. They trucked in soil, but it was of poor fertility, so they rebuilt it with compost, and cover crops, like daikon radishes. Now they are successful farmer-florists—growing flowers without pesticides so that when customers bury their noses in the bouquet, it will be as healthy as can be.

A few scientists also appear in the film. Kristin Veum, USDA soil scientist, says that soil organisms are important because they build the soil back up. Most people know that legumes fix nitrogen, but few know that it’s the microbes in association with the plants’ roots that actually fix the nitrogen from the air.

Indiana farmer Dan DeSutter explains that mulch is important not just to retain moisture, but also to keep the soil cool in the summer. This helps the living organisms in the soil to stay more active. Just like people, good microbes prefer a temperature of 20 to 25 degrees Celsius. When it gets either too hot or too cold, the micro-organisms become less active. Cover crops are also important, explains DeSutter, “Nature abhors a mono-crop.” DeSutter plants cover crops with a mix of three to 13 different plants and this not only improves the soil, but keeps his cash crops healthier.

Nebraska’s Keith Berns plants a commercial sunflower crop in a mulch of triticale straw, with a cover crop of Austrian winter pea, cowpeas, buckwheat, flax, squash and other plants growing beneath the sunflowers. This diversity then adds 15 or 20 bushels per acre of yield (1 to 1.35 tons per hectare) to the following maize crop. Three rotations per year (triticale, sunflower and maize), with cover crops, build the soil up, while a simple maize – soy bean rotation depletes it.

Adding carbon to the soil is crucial, says DeSutter, because carbon is the basis of life in the soil. In Indiana, half of this soil carbon has been lost in just 150 to 200 years of farming, and only 50 years of intensive agriculture. No-till farming reduces fertilizer and herbicide costs, increases yield and the soil improves: a win-win-win. This also reduces pollution from agrochemical runoff.

As Keith Berns explains, the Holy Grail of soil health has been no-till without herbicides. It’s difficult to do, because you have to kill the cover crop to plant your next crop. One option is to flatten the cover crop with rollers, and another solution is to graze livestock on the cover crop, although he admits that it’s “really hard” to get this combination just right.

USDA soil health expert Barry Fisher, says “Never have I seen among farmers such a broad quest for knowledge as I’m seeing now.” The farmers are willing to share their best-kept secrets with each other, which you wouldn’t see in many other businesses.

Many of these farmers are experimenting largely on their own, but a little State support can make a huge difference. In the 1990s in Maryland, the Chesapeake Bay had an outbreak of Pfiesteria, a disease that was killing the shellfish. Scientists traced the problem to phosphorous, from chemical fertilizer runoff. Maryland’s State Government began to subsidize and promote cover crops, which farmers widely adopted. After 20 years, as Chesapeake Bay waterman James “Ooker” Eskridge explains, the bay is doing better. The sea grass is coming back. The blue crab population is doing well, the oysters are back and the bay looks healthier than it has in years.

Innovative farmers, who network and encourage each other, are revolutionizing American farming. As of 2017, US farmers had adopted cover crops and other soil health measures on at least 17 million acres (6.9 million hectares), a dramatic increase over ten years earlier, but still less than 10% of the country’s farmland. Fortunately, triggered by increased consumer awareness, these beneficial practices are catching on, which is important, because healthier soil removes carbon from the atmosphere, reduces agrochemical use, retains moisture to produce a crop in dry years, and grows more food. The way forward is clear. Measures like targeted subsidies to help farmers buy seed of cover crops have been instrumental to help spread agroecological practices. Experimenting farmers must be supported with more public research and with policies that promote healthy practices like mulching, compost, crop rotation and cover crops.

Watch the film

Living Soil directed by Chelsea Wright, Soil Health Institute

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Vermiwash: an organic tonic for crops

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Old know-how, early warning November 22nd, 2020 by

Vea la versión en español a continuación

In the Bolivian Andes, some officials are starting using local knowledge to improve their early warning systems for natural disasters.

For centuries, local farmers have used the signs of nature (clouds, stars, the behavior of plants and animals) to predict disasters like hail, floods and droughts, and to forecast the welcome rains that make crops grow.

Then, starting in 2004, Prosuco (a Bolivian organization) began to organize farmers with an interest in weather and organic farming. These expert farmers, called Yapuchiris, were encouraged to teach other farmers.

In southwest Bolivia, high on the Altiplano, the local government and the Technical University in Oruro are collaborating with some of these organized Yapuchiris to provide early warning, as Professor Gunnar Guzmán explained in a recent webinar. As he put it: the Yapuchiris, using local knowledge of nature, are excellent at making long-term predictions, three to four months in advance. Meteorologists cannot make such predictions, although they are quite accurate at about 4 days in the future.

Olson Paravicini of the Risk Management Unit of the government of Oruro added that the Yapuchiris’ knowledge is local, so that each one forecasts the weather for his or her own community. This matters in a place as big as Oruro. At 53,558 square kilometers, Oruro is about the size of New York state, bigger than the Netherlands. To apply local knowledge of weather over such a large area, Paravicini and colleagues are collaborating with groups of Yapuchiris, gathering their predictions to compile a departmental level forecast to provide early warnings of floods and other nasty weather.

One of the Yapuchiris, Bernabé Choquetopa, also had a slot on the webinar, explaining several of the signs he looks for. For example, when the leque leque (Andean lapwing) migrates back into Oruro in September, don Bernabé looks at its wing. If the patch on the bird’s wing is green, the rains will be good. Green eggs also mean good rain, and dark eggs mean drought. The signs reinforce each other, so after explaining that the ayrampu cactus was bearing lots of fruit and that the foxes had healthy coats, don Bernabé predicted that this would be a good, normal year for rains in his part of Oruro.

Professional weather observers are now paying attention to the Yapuchiris, who are increasingly organized and well respected. Guzmán thinks that some of the local signs of nature are 90% accurate, a probability that increases as several are used together.

Plants and animals that have evolved in a harsh landscape may have behaviors that reflect the coming weather. Observant local people have the wisdom to pay attention to the local patterns of life. I’m optimistic when I see local scientists who have respect for this knowledge. That alone is a good sign for the future.

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Scientific names

Ayrampu: Opuntia soehrensii

Andean lapwing: Vanellus resplendens

Andean fox: Lycalopex culpaeus

Further reading

Unfortunately, I can’t find a recording of the webinar (16 November 2020), but the seminar, the speakers and the titles of their presentations were:

Seminario Virtual Saberes Ancestrales de Bioindicadores Naturales para la Reducción de Riesgos Agropecuarios

Ing. Naida Rufino Challa, SEDAG-GAD ORU (Servicio Departamental de Agricultura y Ganadería, Gobierno Autónomo Departamental de Oruro). Mejoramiento del sistema de alerta temprana del sector agropecuario en el departamento de Oruro.

M.Sc. Ing. Gunnar D. Guzmán Vega, FCAN-UTO (Facultad de Ciencias Agrarias y Naturales, Universidad Técnica de Oruro). Efectividad de los indicadores naturales en la predicción climática en las comunidades.

Bernabé Choquetopa Rodríguez. Informante local. Pronósticos locales 2020-2021 del sur de Oruro.

Ing. Olson C. Paravicini Figueredo, UGR-GAD ORU (Unidad de Gestión de Riesgos, Gobierno Autónomo Departamental de Oruro). Bioindicadores y tecnología informática como sistema integrado de alerta temprana.

SABERES ANTIGUOS, ALERTA TEMPRANA

Por Jeff Bentley, 22 de noviembre del 2020

En los Andes bolivianos, algunas autoridades han empezado a usar los conocimientos locales para mejorar sus sistemas de alerta temprana de desastres naturales.

Durante siglos, los agricultores locales han leído los signos de la naturaleza (las nubes, las estrellas, el comportamiento de las plantas y los animales) para predecir desastres como la granizada, las riadas y las sequías, y para pronosticar las queridas lluvias que nutren a los cultivos.

Luego, a partir de 2004, Prosuco (una organización boliviana) comenzó a organizar a los agricultores interesados en el clima y la agricultura orgánica. Se les alentó a estos agricultores expertos, llamados Yapuchiris, a que enseñaran a los demás.

En el Altiplano del sudoeste de Bolivia, el gobierno local y la Universidad Técnica de Oruro están colaborando con algunos de estos Yapuchiris organizados para dar una alerta temprana, como explicó el Ingeniero Gunnar Guzmán hace poco en un webinar. Según él, los Yapuchiris, con su conocimiento local de la naturaleza, hacen acertadas predicciones a largo plazo, con tres o cuatro meses de anticipación. A cambio, los meteorólogos no pueden hacer eso, aunque hacen buenos pronósticos a unos 4 días en el futuro.

Olson Paravicini, de la Unidad de Gestión de Riesgos del Gobierno Autónomo Departamental de Oruro, añadió que el conocimiento de los Yapuchiris es local, de modo que cada uno pronostica el tiempo para su propia comunidad. Esto es importante en un lugar tan grande como Oruro. Con 53.558 kilómetros cuadrados, Oruro es el tamaño del Costa Rica, más grande que los Países Bajos. Para aplicar el conocimiento local del tiempo en una zona tan grande, Paravicini y sus colegas están colaborando con grupos de Yapuchiris, aprendiendo sus pronósticos para compilar un sistema de alerta temprana a nivel departamental para predecir riadas y otros desastres climáticos.

Uno de los Yapuchiris, Bernabé Choquetopa, también habló en el webinar, explicando varias de los indicadores que él busca. Por ejemplo, cuando el leque rebinar vuelve a Oruro en septiembre, don Bernabé mira su ala. Si es verduzca, las lluvias serán buenas. Los huevos verdes también significan buena lluvia, pero los huevos oscuros significan sequía. Los signos se refuerzan mutuamente, así que después de explicar que el cactus ayrampu estaban cargados de frutos y que los zorros tenían buen pelaje, don Bernabé predijo que este año sería bueno y normal para las lluvias en su sector de Oruro.

Ahora algunos meteorólogos profesionales prestan atención a los Yapuchiris, que son cada vez más organizados y respetados. Guzmán cree que algunos de los signos locales de la naturaleza tienen una precisión del 90%, probabilidad que aumenta a medida que se usan varios indicadores juntos.

Las plantas y los animales que han evolucionado en una tierra inhóspita pueden tener comportamientos que reflejan el tiempo y el clima. La gente local tiene la sabiduría de observar cuidadosamente a los patrones locales de vida. Soy optimista cuando veo que los científicos locales ganan respeto por este conocimiento. Eso sí es una buena señal para el futuro.

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Cultivando orgullo en los Andes

Leyendo el nido del topo

Conocer el futuro

Videos sobre el tema

Hacer un registro del clima

Pronosticar el clima con una aplicación

Nombres científicos

Ayrampu: Opuntia soehrensii

Leque leque: Vanellus resplendens

Zorro andino: Lycalopex culpaeus

Lectura adicional

Infelizmente, no ubico una grabación del webinar (16 de noviembre del 2020), pero el seminario virtual, los discursantes y sus presentaciones eran:

Seminario Virtual Saberes Ancestrales de Bioindicadores Naturales para la Reducción de Riesgos Agropecuarios

Ing. Naida Rufino Challa, SEDAG-GAD ORU (Servicio Departamental de Agricultura y Ganadería, Gobierno Autónomo Departamental de Oruro). Mejoramiento del sistema de alerta temprana del sector agropecuario en el departamento de Oruro.

M.Sc. Ing. Gunnar D. Guzmán Vega, FCAN-UTO (Facultad de Ciencias Agrarias y Naturales, Universidad Técnica de Oruro). Efectividad de los indicadores naturales en la predicción climática en las comunidades.

Bernabé Choquetopa Rodríguez. Informante local. Pronósticos locales 2020-2021 del sur de Oruro.

Ing. Olson C. Paravicini Figueredo, UGR-GAD ORU (Unidad de Gestión de Riesgos, Gobierno Autónomo Departamental de Oruro). Bioindicadores y tecnología informática como sistema integrado de alerta temprana.

Building a better fruit fly trap August 16th, 2020 by

The Mediterranean fruit fly is a worthy enemy. This pest, also known as the medfly, is widespread over the tropics, attacking and spoiling oranges, mangos and many other fruits. Each female can lay 200 eggs in her brief lifetime—allowing rapid population growth. The medfly damages so much high value fruit, that many people would like to eradicate it entirely.

The medfly has inspired some bizarre responses, such as spraying suburban Los Angeles with Malathion (insecticide) in the 1980s. Then there is the sterile male technique, which has been used from South America to South Africa to the US citrus belt, where billion of the flies are reared in labs, and treated with enough nuclear radiation to make the males sterile. These hapless males are then dropped from airplanes to mate with wild females, who then have no offspring. These programs to eradicate fruit flies over all of Guatemala, for example) are often described as successful, cost-effective and environmentally friendly. They are also large, expensive and highly technical affairs.

Low technology has also been tried. In Bolivia, the soda pop bottle trap has been around for perhaps 20 years, although it has not been widely adopted. You take a plastic drink bottle, punch some fly-sized holes in the side, pour in half a cup of orange juice and hang the bottle from an orchard tree, about shoulder height. The flies come for the juice, fly into the hole, but usually can’t find their way out of the bottle again and drown in the juice.

It’s fine in theory, but when I saw the traps being used in the field, the farmers had quickly given up on them, allowing the orange juice to decay to a black rot. The farmers had tried a trap or two and abandoned the idea. The traps may have needed some further tweaking.

Our personal battle with the medfly began three years ago, when we couldn’t get them out of our guava tree. Entomologist Luis Crespo told us that the flies love guava so much that peach growers have to cut down their guava trees as a first step to managing the pest (The best knowledge is local and scientific). But Luis kindly gave us a pheromone trap, which attracts flies with a sexual scent lure. The flies land on the trap’s sticky surface and die.

Pheromones typically trap one particular species of fly, but we had several, and by then the soil around our guava tree was full of pupating and highly fertile fruit flies. We reluctantly pruned our guava so it wouldn’t bear fruit, but by last year we were getting fruit fly larvae in our tomatoes and even in our avocados, (not a major fruit fly host).

The war was on. We loathed the thought of fruit flies in our avocados, and this was our last chance to stamp out the fly. We uprooted all our tomatoes. Ana and her dad made dozens of traps. Even a technology made from a pop bottle can evolve. We had seen improved models displayed by students at the local fair sponsored by the agricultural college.

You can make a better trap by painting a yellow stripe around the entry holes. Fruit flies are attracted to the color yellow. Take two bottles and make a T-shaped trap. As the flies ascend from the juice to the top of the bottle, they fly into the second bottle and cannot find their way out again. During the mild winter, we may have two to four flies in each pop bottle trap, while the old traps made from a single bottle would catch one or two medflies.

It seemed like a waste to squeeze fresh juice for flies, but we learned with experience that even when the orange juice was a month old, the fruit flies still swarmed to it because they are attracted to fermenting fruits and vegetables.

Traps might also work in a commercial orchard, if you could get hundreds of pop bottles. People are starting to manufacture yellow traps and there are alternative baits (like chicha, a local, low-alcohol brew, which is already fermented and easier to get than orange juice). In spite of our improvements, one has to attack fruit flies with several weapons at once. Our traps are better for monitoring than for total fruit fly control. If not for the Covid lockdown, we would buy some low-toxic insecticide to make more lethal food traps. And we won’t know until our next avocado crop comes in if we have eradicated our fruit flies or not, but at least we have a better fly trap.

Scientific name

The Mediterranean fruit fly is Ceratitis capitata, but other fruit fly genera in Bolivia include Anastrepha and Bactrocera.

Related blog story

Guardians of the mango

Related videos

Killing fruit flies with food baits

Weaver ants against fruit flies

Collecting fallen fruit against fruit flies

Integrated approach against fruit flies

Further reading

Enkerlin, W. R., J. M. Gutiérrez Ruelas, R. Pantaleon, C. Soto Litera, A. Villaseñor Cortés, J. L. Zavala López, D. Orozco Dávila et al. 2017 The Moscamed Regional Programme: Review of a Success Story of Area‐Wide Sterile Insect Technique Application. Entomologia Experimentalis et Applicata 164(3):188-203.

Validating local knowledge July 26th, 2020 by

Vea la versión en español a continuación

Paul and I have written earlier stories in this blog about the yapuchiris, expert farmer-researcher-extensionists on the semi-arid, high plains of Bolivia. At 4000 meters above sea level (over 13,000 feet), seasoned farmers know how to observe plants and animals, clouds and stars, to predict the weather, especially to answer the Big Question on their minds: when will the rains start, so I can plant my crop?

All of the yapuchiris know some traditional ways of predicting the weather. Some yapuchiris also write their observations on a special chart they have designed with their agronomist colleagues at Prosuco, an organization in La Paz. The chart, called a Pachagrama, allows the yapuchiris to record the weather each day of the year, just by penciling in a few dots, so they can see if their predictions come true, and how the rains, frosts and hail affect their crops.

It can be daunting to prove the value of local knowledge, but it is worth trying.

Eleodoro Baldivieso is an agronomist with Prosuco, which has spent much of the past year studying the results of the Pachagrama weather-tracking charts. As he explained to me recently, Prosuco took four complete Pachagramas (each one filled out over seven years) containing 42 cases; each case is a field observed over a single season by one of the yapuchiris. Comparing the predicted weather with the recorded weather allowed Prosuco to see if the Pachagramas had helped to manage risk, mainly by planting a couple of weeks early, on time, or two weeks late.

Frost, hail and unpredictable rainfall are the three main weather risks to the potato and quinoa crops on the Altiplano. In October, a little rain falls, hopefully enough to plant a crop, followed by more rain in the following months. Average annual rainfall is only 800 mm (about 30 inches) in the northern Altiplano, and a dry year can destroy the crop.

For the 42 cases the study compared the yapuchiri’s judgement on the harvest (poor, regular, or good) with extreme weather events (like frost), and the planting date (early, middle or late) to see if variations in the planting date (based on weather predictions) helped to avoid losses and bring in a harvest.

The study found that crops planted two weeks apart can suffer damage at different growth stages of the plant. For example, problems with rainfall are especially risky soon after potatoes are planted, affecting crops planted early and mid-season. Frost is more of a risk for early potatoes at the start of the season, and for late potatoes when they are flowering. Hail is devastating when it falls as the mid and late planted potatoes are flowering.

The yapuchiris are often able to accurately predict frost, hail, and rainfall patterns months in advance. Scientific meteorology does a good job predicting such weather a few days away, but not several months in advance. When you plant your potatoes, modern forecasts cannot tell you what the weather will be like when the crop is flowering. Forecasting the weather in a challenging environment is helpful, at least some of the time. Planting two weeks early or two weeks late may help farmers take best advantage of the rain, but then expose the crop to frost or hail. Changing the planting dates can help farmers avoid one risk, but not another.

The weather is so complicated that risk can never be completely managed. And because scientific meteorology cannot predict hail and frost months in advance, local knowledge fills a void that science may never replace.

Previous blog stories

Cultivating pride in the Andes

To see the future

Predicting the weather

Watch the video

Recording the weather

Watch the presentation by Eleodoro Baldivieso (in Spanish)

http://andescdp.org/cdp16/seminarios/seminario_4_respondiendo_amenazas_productivas/yapuchiris_Prosuco

Acknowledgement

This work with weather is funded by the McKnight Foundation’s Collaborative Crop Research Program (CCRP). Francisco Condori, Luciano Mamani, Félix Yana and Santos Quispe are the yapuchiris who participated in this research. Thanks to Eleodoro Baldivieso, María Quispe, and Sonia Laura of Prosuco for reading and commenting on a previous version of this story. The first two photos are courtesy of Prosuco.

VALIDANDO LOS CONOCIMIENTOS LOCALES

Por Jeff Bentley

26 de julio del 2020

Paul y yo hemos escrito historias anteriores en este blog sobre los Yapuchiris, expertos agricultores-investigadores y extensionistas en el Altiplano semiárido boliviano. A los 4000 metros sobre el nivel del mar, los agricultores experimentados saben cómo observar plantas y animales, nubes y estrellas para predecir el clima, especialmente para responder a la Gran Pregunta en sus mentes ¿cuándo comenzarán las lluvias para yo pueda sembrar mi chacra?

Todos los Yapuchiris conocen algunas formas tradicionales de predecir el tiempo. Algunos Yapuchiris también apuntan sus observaciones en un cuadro especial que han diseñado con sus colegas, los ingenieros agrónomos de Prosuco, una organización en La Paz. El cuadro, llamado Pachagrama, permite a los Yapuchiris registrar el tiempo cada día del año, con sólo dibujar algunos puntos, para que puedan ver si sus predicciones se hagan realidad y como las lluvias, heladas y granizadas afectan sus cultivos.

Puede ser difícil comprobar ese conocimiento local, pero vale la pena intentarlo.

El Ing. Eleodoro Baldivieso, de Prosuco, ha pasado gran parte del año pasado estudiando los resultados de los Pachagramas. Cómo él me explicó hace poco, Prosuco tomó cuatro Pachagramas completos (de siete campañas agrícolas) y 42 casos; cada caso es una parcela observada durante una campaña por uno de los yapuchiris. El comparar el tiempo previsto con el tiempo registrado permitió a Prosuco ver si los Pachagramas habían ayudado a manejar el riesgo, principalmente mediante la siembra temprana (dos semanas antes), intermedia y tardía (dos semanas después).

Las heladas, el granizo y la lluvia impredecible son los tres principales riesgos meteorológicos para los cultivos de papa y quinua en el Altiplano. En octubre cae un poco de lluvia, con la esperanza de que sea suficiente para sembrar un cultivo, seguida hasta marzo por más lluvia. La precipitación media anual es sólo 800 mm en el Altiplano Norte, y un año seco puede destruir la cosecha, lo mismo que un año con mucha lluvia.

Para los 42 casos el estudio comparó la evaluación del Yapchiri de la cosecha (malo, regular, o bueno) con eventos extremos de tiempo (como heladas), con las fechas de siembra (temprano, mediano, o tarde) para ver si el variar la fecha de siembra (basado en el pronóstico del Yapuchiri) ayudó a evitar pérdidas y lograr una cosecha.

El estudio halló que los cultivos sembrados a dos semanas de diferencia pueden sufrir daño en diferentes etapas de crecimiento da las plantas. Por ejemplo, los problemas con las lluvias son especialmente arriesgados poco después de la siembra de la papa, afectando más a la siembra tempran, a principios y mediados de la temporada. Las heladas son más riesgosas para las papas tempranas al comienzo de la temporada, y para las papas tardías justo en la época de floración. El granizo es devastador para las siembras intermedias y tardías, si la papa está en flor.

Los Yapuchiris a menudo son capaces de predecir con certeza las heladas, el granizo y los patrones de lluvia, con meses de antelación. La meteorología científica a menudo puede predecir ese tiempo a unos pocos días, pero con meses de anticipación. Cuando siembras tu papa, el pronóstico moderno no te puede decir cómo será el tiempo cuando tu cultivo está en flor. Pronosticar el tiempo en un entorno desafiante es útil, al menos parte del tiempo. Sembrar dos semanas antes o dos semanas después puede ayudar a los agricultores a aprovechar mejor la lluvia, pero se expone el cultivo a las heladas o granizo, cuando es más vulnerable. Cambiar las fechas de siembra puede ayudar a los agricultores a evitar uno de los riesgos, pero no siempre a todos.

El clima es tan complicado que el riesgo nunca puede ser manejado completamente. Y debido a que la meteorología científica no puede predecir el granizo y las heladas con meses de anticipación, el conocimiento local llena un vacío que la ciencia tal vez nunca reemplace.

Historias previas del blog

Cultivando orgullo en los Andes

Conocer el futuro

Prediciendo el clima

Ver el video

Hacer un registro del clima

Vea la presentación por Eleodoro Baldivieso (en español)

http://andescdp.org/cdp16/seminarios/seminario_4_respondiendo_amenazas_productivas/yapuchiris_Prosuco

Agradecimiento

Este trabajo con el clima es financiado por el Programa Colaborativo de Investigación sobre Cultivos (CCRP) de la Fundación McKnight. Francisco Condori, Luciano Mamani, Félix Yana y Santos Quispe son los Yapuchiris que participaron en esta investigación. Gracias a Eleodoro Baldivieso, María Quispe, y Sonia Laura de Prosuco por leer y hacer comentaros sobre una versión previa de esta historia. Las primeras dos fotos son cortesía de Prosuco.

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