The following is an excerpt from Ronnie Cummin and Andre Leu’s new book The Regenerative Agriculture Solution (Chelsea Green Publishing September 2024) and is printed with permission from the publisher.
A Revolutionary Innovation
The Flores González brothers’ revolutionary innovation has been to turn a heretofore indigestible, but massive and accessible, source of fiber, biomass, water, and protein—the agave leaves or pencas—into a valuable animal feed, utilizing the natural process of anaerobic fermentation to transform the plant leaves’ relatively indigestible saponin compounds into digestible carbohydrates and sugar. To raise protein levels in the silage, the Vía Orgánica research farm combines the wet agave silage (with 3 to 5 percent protein) with dry agave flour (9 percent protein) and/or other protein supplements such as legumes to achieve the desired protein levels.
To shred the pencas or piñas for wet silage, the Zamarripa pioneers have designed and built a relatively simple machine, either self-powered, hooked up to a tractor, or electric-driven, that can chop up the very tough pruned leaves of the agave, producing over 1 ton of wet silage per hour. After shredding the agave’s leaves or pencas (into what looks like green coleslaw) they anaerobically ferment this wet silage in a closed container, such as a 5- or 50-gallon plastic container with a lid, removing as much oxygen as possible (by tapping it down) before closing the lid. A separate machine, fairly simple and inexpensive, can grind mesquite pods, beans, moringa plants, or dried agave leaves into a higher protein agave flour.
The fermented end-product, golden-colored after 30 days, and good for 30 months, is a nutritious but inexpensive silage or animal fodder, which costs approximately 1.5 Mexican pesos (or 7.5 cents USD) per kilogram (or 2.2 pounds) for fermented agave alone, or 3 pesos—for agave and mesquite/bean pods or agave flour together—per kilogram to produce. In San Miguel de Allende, the containers used during the initial experimental stage of the project cost $3 per unit for a 20-liter or 5-gallon plastic container or cubeta with a lid, with a lifespan of 25 uses or more before they must be recycled. Two hundred–liter reusable containers cost $60 per unit (new;$30 used) but will last considerably longer than the 20-litercontainers. At Vía Orgánica, before feeding our animals (sheep, goats, pigs, chickens, ducks, turkeys, rabbits, burros) the silage, we add dried agave flour or other protein sources like beans or alfalfa to augment protein.
As the preliminary numbers indicate, fermenting agave silage, harvesting and processing the pencas alone, will provide significant value and profits per hectare for landowners and rural communities, such as Mexican ejidos, who deploy the agave agroforestry system at scale. In addition, Billion Agave Project researchers are now developing silage storage alternatives that will eliminate the necessity for the relatively expensive 20-liter or 200-liter plastic cubetas.
Regenerative Economics
The agave silage production system can provide the cash-strapped rancher or farmer with an alternative to having to purchase alfalfa (expensive at 20 to 40 cents USD per kilogram and water-intensive), hay (likewise expensive), or corn stalks (labor intensive and nutritionally deficient), especially during the dry season.
According to Dr. Juan Frias, lead scientist for Vía Orgánica, lambs or adult sheep readily convert 10 kilos of fermented agave silage (wet) into 1 kilo of body weight, half of which will be marketable as meat or viscera. At 1.5 to 3 pesos per kilo (7.5 to 15 cents per pound), this highly nutritious silage can eventually make the difference between poverty and a decent income for literally millions of the world’s dryland small farmers and herders.
Typically, an adult sheep will consume 2 to 2.5 kilograms of silage every day, while a lamb of up to 5 months of age will consume 500 to 800 grams per day. Cattle will consume 10 times as much silage per day as sheep, approximately 20 to 25 kilograms per day. Under the agave system it costs approximately 20 pesos ($1) per pound in live weight to produce sheep and goats. These can be sold at market rates for non-organic mutton or goats at 40 pesos ($2) per pound live weight. Certified organic lamb, mutton, or goat will bring in 25 to 50 percent more. In ongoing experiments in San Miguel de Allende, pigs and chickens have remained healthy and productive with fermented agave forage providing 15 to 50 percent of their diet, reducing feed costs considerably.
The bountiful harvest of this regenerative, high-biomass, high-carbon-sequestering system includes not only extremely low-cost, nutritious animal forage (up to 60 to 100 tons or more, depending on the variety per hectare per year of fermented silage—starting in years 3 to 5, averaged out over 10 years), but also high-quality organic lamb, mutton, cheese, milk, aquamiel (agave sap), pulque, inulin, and mescal, all produced organically with no synthetic chemicals or pesticides whatsoever, at affordable prices, with excess agave biomass fiber, and bagasse available for textiles, pet food, compost, biochar, construction materials, and bioethanol.
