Because Bolivia’s social distancing regulations have prohibited in-person classes, Mano a Mano staff at our Center for Ecological Agriculture (CEA) in Cochabamba have decided to use these months of down time to experiment with new demonstration projects. Their goal: to grow more food, in less space and at lower cost, using technology and materials that can be made available to remote rural communities.
Hydroponic Vegetable Production
For several months, the CEA has been implementing the first of its experimental projects: using hydroponic methods to raise lettuce.
Hydroponic gardening is a method of growing plants without soil. In a typical garden, plant roots seek nutrients in the soil; in a hydroponic garden, nutrients are dissolved in water that slowly flows across the roots. Seeds, each imbedded in a slot cut into a small sponge, germinate in shallow trays, stacked six to eight high on shelves held temporarily in a space that is darkened for 2-3 days while the seeds germinate. When the germinated seeds begin to show the formations of a plant, the sponge with the seed is placed in a vessel, a screened plastic cup that fits in a circular opening cut into a PVC pipe. Once all seeds have been transferred, the hydroponic pump begins to cycle the nutrient-filled water throughout the structure. The barely forming roots of each plant reach into the water to draw out the nutrients needed to grow.
Using the hydroponic method, Mano a Mano is now growing nearly 1,000 lettuce plants in a 66 square meter structure in a 28-35-day period (in contrast to the 45-55 days required for lettuce planted in a 25% larger plot of land). And the hydroponic method yields 8-9 crops, in contrast to 4 yearly for traditional methods. Space at the 2.5-acre CEA must be used as productively as possible. Having found that this simple hydroponic method produces more food in less space and uses less water (a resource that is scarce throughout the region), CEA staff plan to expand the experiment to include other highly nutritious foods such as tomatoes and avocados.
The CEA will teach hydroponic methods to farmers when it can safely begin classes. Cochabamba’s location, at an altitude of about 8,500 meters with its moderate climate, makes it possible to practice this crop-growing method inside a simple plastic tent. Even at higher altitudes where Mano a Mano has constructed most of its greenhouse projects, Mano a Mano is confident that a fully enclosed and sealed plastic enclosure will be sufficient to protect tender plants from the cold mountain winds.
To make good use of the lettuce that the CEA is producing, staff package it under the Mano a Mano label and sell it to restaurants. Income from these plants helps support the hydroponics garden and other CEA projects. Any imperfect lettuce leaves provide an additional source of feed for the guinea pigs, rabbits, chickens, sheep, and pigs raised at the CEA.
Hydro-Green Fodder Production for Animal Feed
High Andean farmers typically raise a few animals to supplement their mostly corn and potato-based diet. For this reason, CEA classes include training farmers to raise healthy animals. The CEA’s plots of alfalfa and grass have provided the primary food source for its animals. To decrease the amount of land required to raise these crops and to make more feed available, the CEA began its second experiment this month.
Staff welded together shelving units that will hold close to 1,000 trays, each fitted on metal racks designed to hold one kilogram of grain, such as corn, oats, barley, or wheat. To gain time, the agronomist places water-soaked grain in a dark, moist, and cool place. In 2-3 days (less time in summer, more in winter) grains will sprout into plants and are placed in the trays. Trays will be sprayed with a water mist up to eight times daily. Within another 7-9 days, the entire tray will be covered with a mat of roots and plants that can be removed and fed to farm animals. Starting with 2 pounds of grains, we end up with 10 pounds of feed in about 10 days.
Fodder System Experiments in Video (July 2020)
This food production method will make it possible for the CEA to reduce the amount of land planted with alfalfa and grass and to use those plots for other purposes.
Ben Martinez, the CEA’s director, Juan Carlos Cardenas, our lead agronomist, and 2 agronomy technicians who interned at the CEA are taking responsibility for designing and carrying out these experiments.