BioCycle June 2004, Vol. 45, No. 6, p. 56
Based on a small-scale, locally self-sufficient approach, earthworms – through vermiculture – are now an important part of an effort in Cuba to restore the health and productivity of its agriculture.
Jeri L. Berc, Olegario Muñiz and Bernardo Calero
CUBA has applied its education and extension system to combine traditional methods with modern science, thereby establishing a national program for production and use of organic matter and biofertilizers.
Work has been carried out with the cooperation of the Cuban research centers, universities, farmers’ organizations (Asociación Nacional de Agricultores Pequeños), government ministries and nongovernmental organizations (Asociación Cubana de Técnicos Agrìcolas y Forestales, Cuban Society of Soil Science, etc). Through this program, alternative technologies such as the production and utilization of vermicompost, compost, green manures, biofertilizers (Rhizobium, Azotobacter, Azospirillum, Mycorrhizae and Phosphorus-Solubilizing microorganisms), use of residues of the sugarcane industry and the soil amendment zeolite, have been researched and implemented. Use of these products is rapidly increasing. Use of vermicompost has increased 20 times since 2000 (Table 1).
Cuba is a highly agrarian country. Of a total of 11 million hectares, 6.7 million ha are suitable for agriculture and 4.5 million ha are cultivated. Of the land not suitable for cultivation, forests cover 2.6 million ha. The change in the agricultural technology paradigm has been accompanied by an equally dramatic change in land tenure relationships, and private marketing opportunities and incentives.
Since 1990, State farm holdings have decreased from over 75 percent of arable land to less than 30 percent. These large state farms and enterprises have been redistributed to those interested in cultivating the land as individuals, families, or in small cooperatives; 3,000 new cooperatives have been established.
New incentives are being offered for the production of many crops such as tobacco, cocoa, coffee, and rice, stimulating growth in diverse agricultural and livestock activities. Free agricultural markets were created in 1994, where farmers can sell production surpluses at prices set by supply and demand.
Urban Agriculture Developments
In addition to these changes in rural agriculture, a strong agriculture movement is also developing in Cuban cities and suburbs. The goal of this movement is diverse fresh produce from unused urban land and local resources applying organic fertilizers, biological pest control, and direct marketing in local communities.
Annual fresh vegetable and herb production through organoponics and gardens in small plots and backyards has increased from almost 1 million tons in 1999 to 3.7 million tons in 2003. Organoponics is a crop production technique on raised beds consisting of 50 percent organic matter (preferably worm humus) and 50 percent soil.
Vermiculture And Vermicompost
Vermicompost is a very high-quality fertilizer produced from organic wastes – organic manures, cachaza (sugarcane production filter cake residue), crop residues, etc. by earthworms (see Table 2). As the organic material passes through the worm’s digestive tract, it is converted into a bacteria-rich material that can be easily handled, transported, stored and applied as a soil fertilizer. Production is carried out both on a small farm scale and commercial scale.
The worm species used in Cuban vermiculture are primarily the California Red (Eisenia foetida) and to a lesser extent the African Red (Eudrilus eugeniae). The California Red is used because it is characterized by extremely fast reproduction, especially under high ambient temperatures, and tolerates the very high population densities (10,000 to 50,000 worms/m2) needed to promote quick decomposition. It is a very prolific worm which begins reproduction at 3 months, mating thereafter every 10 days. Each egg capsule yields an average of 2 to 10 live worms. Additionally, this worm can resist variations in temperature, pH and humidity, and prospers in a variety of substrates. Partial shading and moisture control are required.
In subtropical conditions where worms can be harvested three times per year, on one square meter of land, the California Red can produce up to 1.5 tons of humus from 3 tons of organic substrate in one year. This high quality humus can be used on various crops to replace chemical fertilizers (Table 3). The use of worm humus generates economical yields, high quality products, as well as soil property restoration.
Worm Humus Production
Worm humus is produced in Cuba primarily in raised beds under the shade of banana or mango plantings. The recommended size of the raised beds is: 1.2 to 1.5 meters wide and 30-60 meters long. The orientation of the length of the bed should be north to south to minimize exposure to sun. To prepare the site, workers are instructed to level the selected area, apply a 15 centimeter (cm) layer of substrate and irrigate with water. Substrates of a mixture of organic materials, both high in nitrogen (eg. manures), and low in nitrogen (eg. plant residues) are preferable.
On the surface of the new bed, the recommendation is to apply 5,000 earthworms per square meter. Add 10 cm layers of substrate to the beds every 15 days (depending on the speed of worm growth and substrate transformation). After three months, the frequency of addition could increase to every seven days. Irrigate the surface 10 cm of the bed to maintain high humidity. Worm humus may be collected when the raised bed is 60 centimeters high, usually within three to four months. Side walls for the beds are not necessary. Beds may taper toward the surface, as they get higher.
When humus is harvested, a mesh material should be placed on top of the pile through which the earthworms may just pass, and then apply and irrigate a final layer of fresh substrate. Worms will move up into the new substrate through the mesh. After three to four days, the mesh with the substrate and most of the worms can be removed to start another raised bed. Then the finished worm humus can be collected and used.
Jeri L. Berc is Special Assistant to the Deputy Chief, Soil Survey and Resource Assessment, U.S. Department of Agriculture, Natural Resources Conservation Service, Washington DC. Olegario Muñiz, Ph.D. is Subdirector, La Renee Experiment Station, Cuban Soils Institute in Havana, Cuba. Bernardo J. Calero, Ph.D. is Subdirector of Investigations, Microbiology, Cuban Soils Institute in Havana, Cuba.
CITMA, Cuban Ministry of Science, Technology and Environment, 1998. Programa de Acción Nacional de Lucha Contra la Desertificación y la Sequìa en la República de Cuba. Havana.
Funes, F., Garcìa, L., Bourque, M., Perez, N. and Rosset, P. 2001. Transformando el Campo Cubano: Avances de la Agricultura Sostenible. Asociación Cubana de Técnicos Agrìcolas y Forestales, Havana.
Martìnez, F., Calero, B., Nogales, R. and Rovesti, L. 2003. Lombricultura. Manual práctico. Soil Institute La Habana.
Muñiz, O.1996. Los Sistemas Integrados de Nutrición Vegetal. En: Resumenes de la IV Jornada Cientìfica del Instituto de Suelos, La Habana.
PROFILE OF A VERMICOMPOST PRODUCER
ARIEL CUESTA is the young owner of a farm situated in the Quivican District of Cuba. His farm is a model that other farmers in this District visit to learn about his operations. The farm consists of 20 hectares of fertile and productive soil, (a Rhodic Ferralsol – which is the most common soil of the province). He produces high quality sweet potato, malanga (caro), fruits (banana, mango, avocado, etc.) and vegetables throughout the year. Vermicompost is the main fertilizer applied to the fields and orchards. Ariel produces 24 tons of vermicompost every month primarily from cattle manure and cachaza (sugarcane processing residue) that he purchases near his farm. His farm is equipped with a tractor, a truck, two water wells with electric turbines for a gravity irrigation system, and working animals. Ariel manages to clear good profits after paying 20 employees and taxes. The Cuban government supports the operation through equipment loans and subsidized prices on fuel and other inputs.
June 15, 2004 | General
Vermiculture Offers A New Agricultural Paradigm (Cuba)
BioCycle June 2004, Vol. 45, No. 6, p. 56