This diary is part of a series describing my trip to Bolivia to study food sovereignty, agroecology, and climate change. Our twelfth day was one I was eagerly anticipating. We left the city of Santa Cruz for two days with Productividad Biosfera Medio Ambiente (PROBIOMA). First, they took us to their training center, where we would spend the night, where they presented on their work. Then we visited a small, organic farm. The next day they took us to the heart of the industrial ag region of the department where we saw responsible soy production and lots of irresponsible soy production.
This post covers the last of a very long, tiring (but wonderful) day with PROBIOMA, in which they presented to us on some of the specific biological pest controls they promote.
The next presentation went into more specific details about biocontrols. Here is what was said, to the best of my ability to transcribe it:
The talk was about agroecological management strategies. Our presenter said that the solution to Bolivia's food sovereignty is not the expansion of the agricultural frontier but in the improvement in the management of farmland. PROBIOMA works with communities and producers associations so they can identify their own problems, their own priorities, because it's very difficult for individual smallholders to do that by themselves. PROBIOMA could have some idea of what's best for the producers, but they have to develop that and arrive at it on their own with their own priorities so they don't become dependent on PROBIOMA.
They identify, for example, a problem in a certain crop. Let's say something is attacking their fruit, or there's a plant disease, an insect attacking vegetables. So let's say there are aphids (pulgones). After identifying the problem, making the diagnosis, they come together to make a decision. They identify the proper way to apply bioregulators to address the problem. The agrochemicals they often use will cause imbalances with the relationships in between insects, microbes, and plants, so we come in with these bioregulators to try to restore this balance. The goal is to increase the amount of healthy, safe food produced. With the efficient and correctly timed use of biological control, we've been able to increase yields.
An important component is training in nutrition. Sometimes it's important to note that the actual pest that is causing the problem is actually the least important part of the problem, it's more of a systematic problem. The first thing PROBIOMA looks at are the elements of soil. A healthy soil with lots of microorganisms - a living soil - yields strong plants. One thing they use is a fertilizer called bocachi. It is made from locally available resources: straw, manure, charcoal, wheat husks, molasses, and yeast. They mix it and after 20 days it is ready to incorporate into the soil.
He then showed us a sponge with 2 million beneficial nematodes in it. To use it, a producer soaks it in water and then sprays the water-and-nematodes on the soil. It takes 10 sponges per hectare to control the pests. The sponges sell for about US$2. Later, they showed us a demonstration of the nematodes in action, under a microscope. The nematode will control for larvae of an insect that eats the roots of plants. The nematode carries a bacteria with it, and when it finds a larva, it inoculates it with the bacteria. The bacteria will multiply, killing and digesting the larva, and then the nematode eats the bacteria.
The larva, already dead and being eaten by the bacteria and nematodes.
Tanya looks at the larvae and nematodes under the microscope to see it in action. One of the sponges with nematodes is next to her on the table.
Cultures of bacteria and nematodes.
Another microorganism PROBIOMA uses is trichoderma, a beneficial fungi that controls a number of soil diseases. For example, it controls early blight (tizón temprano). In the case of potatoes, we apply it directly after planting the seed. Then we apply the bocachi and cover it with soil. They also use liquid "teas" (like compost tea) - I think an example of one they do this with are white flies (moscas blancas). And they use insect pheromones to attract and trap pests like moths (polillas). In their system, he said, they can double potato yields compared to conventional systems.
They also work in organic quinoa production. He said of the 35 municipalities in Oruro, 32 are already in the process of desertification. So they work there in soil management. Trichoderma eliminates the toxic residues in soil and also helps the seed germinate. They use 100cc of their trichoderma product plus 200cc water per 8 kg seeds.
And, he said, they use light traps to catch moths, along with pheromones. They work to conserve the natural predators and beneficial insects too, like beneficial wasps in the family Braconidae. The wasp lays its eggs in the pest larva and then when the wasps hatch they eat the larva. Of course, they also use ladybugs as a control. They also use bait (cebo) to attract beneficial insects to come kill the pests.
Another organism they use is a fungi called Beauveria bassiana, which parasitizes and kills a number of types of pest insects. All in all, they have 300 types of beneficial organisms - fungi, bacteria, and nematodes - to use on over 60 crops all over Bolivia.