By Henrylito D. Tacio
IT all started when some members of the San Miguel Multipurpose Cooperative (SMMPC) in Bohol learned the process of producing organic fertilizer using earthworms. Convinced of the bright prospects of vermicomposting, the cooperative invested money into the project.
As prices of commercial fertilizer went up, farmers in the area started using the organic fertilizer in their farms. They paid only P350 for a 50-kilo sack while a bag commercial fertilizer was sold at over P1,500.
A farmer needs about five to seven bags of chemical fertilizers to provide a hectare of land planted to rice with the needed nitrogen and potassium. “Now, we cannot keep up with the demand,” Norberto Buñao, former SMMPC chair, was quoted as saying by a national daily. “Our compost is sold even before we produce them.”
The local government is thinking of making Bohol the center of organic agriculture in the Philippines. “With vermicomposting, we not only earn extra income, we also contribute to the management of solid waste, protection of the environment and promotion of organic agriculture,” Buñao pointed out.
But SMMPC members are not the only people discovering the viability of vermicomposting. The Aquatic Biosystems in Bay Laguna is the company that pioneered the technology in the country. It has exported vermicompost to Hong Kong.
The council of barangay Sun Valley in Parañaque operates a vermicomposting plant that processes household wastes into vermicompost and “vermi tea” (liquid fertilizer). It produces about one ton of vermicompost per week.
The Buro-Buro Springs Vermi Farm in barangay Concepcion, Talisay City in Negros Occidental was the first commercial vermicomposting farm the country. But one of the biggest vermicompost producers in the country is Alex Amor of Sibulan, Negros Oriental who produces l0-l5 tons of vermicompost per day.
The Earthworm Sanctuary in San Francisco del Monte, Quezon City, produces about 500 kilos or half a ton of vermicompost every month. “We have now reached the stage where, because of the voracity of the earthworms, we have to ask around for leaves and grass to feed our earthworms,” said owner Antonio de Castro.
The local markets for vermicompost are big. In 1993, the potential use of organic fertilizer covered 2.5 million hectares in the Philippines. That year, the demand for organic fertilizer in 1993 was 6.25 billion bags (50 kg/bag) compared to actual consumption of only 62,000 metric tons.
Vermicomposting in the Philippines began in the 1970s with studies conducted by researchers of the Central Luzon State University in Munoz, Nueva Ecija. However, it did not take off as expected.
It was not until Dr. Rafael D. Guerrero III, director of the Laguna-based Philippine Council for Aquatic and Marine Research and Development (PCAMRD), took a second look at the technology that it started to gain popularity.
Dr. Guerrero wanted to utilize vermicomposting to improve soil fertility, reduce costs and mitigate pollution in the Philippines. “We have a robust agricultural economy with our extensive land and water resources,” he said. “The production of crops such as rice, coconut and sugarcane, along with fisheries (aquaculture), is the mainstay of our agricultural base.”
He found out that one of the major constraints in the production of crops and fish in the country was the high cost of inputs, particularly imported chemical fertilizers for crop production and feeds for aquaculture. Of environmental concern was the widespread burning of crop residues such as rice straw and sugarcane trash.
“About 24 million tons of rice straws are generated annually,” Dr. Guerrero said. “Livestock manure poses additional challenges. Approximately 28 million tons per year are generated, and improper discharge into water bodies is causing aquatic pollution and fish kills.”
So, he thought of turning these wastes into organic fertilizer using vermicomposting or the process of converting biodegradable wastes from households and farms into compost (organic soil) through the action of earthworms.
“With the aid of aerobic microorganisms (that is, bacteria and fungi), earthworms digest processed organic materials under favorable temperature and moisture conditions,” Dr. Guerrero further said. “The materials that pass through the digestive tract of the earthworms come out in a texturized, sanitized and deodorized form of castings known as vermicompost.”
Several earthworms have been identified that can convert wastes into organic fertilizer. Dr. Guerrero, however, preferred the African nightcrawler species (Eudrilus eugeniae), a voracious processor of organic wastes. “Weighing just a gram each, they can eat the equivalent of their weight in organic material every day,” he said.
African nightcrawler earthworm has a high reproductive rate (an adult breeding earthworm produces 3.6 cocoons per week) and can thrive in a wide range of environments that duplicate its ideal living conditions.
There are several advantages of vermicompost. Raw materials for composting are available anytime of the year, which include rice straw, coconut saw dust, coco coir, madre de cacao leaves and household wastes such as rotten vegetables. As such, no imported inputs are required. In addition, the technology is environment-friendly: it turns trash to cash and improves soil health.
But most importantly, vermicompost can improve crop yields, as recent studies have shown. “While low in major plant nutrients compared to chemical fertilizers,” Guerrero said, “vermicompost supports microorganisms, which make nutrients more readily available to plants and produce substances that promote plant growth and health.”
Studies on the use of vermicompost for crop production show that application of chemical fertilizers can be reduced up to 100 percent for certain vegetables and corn, and by 50 percent for rice and sugarcane. A field experiment using vermicompost with corn at 5 tons per hectare increased ear lengths of plants by 114 percent, with the total yield comparable to that of plants fertilized at the recommended rate of inorganic fertilizer.
For sugarcane, the use of 2 tons per hectare of vermicompost, plus 50 percent of chemical fertilizer, increased the yield by 2.6 times compared to the usual yield using 100 percent chemical fertilizer.
In a recent pot experiment conducted on eggplant, results showed that a combination of vermicompost at 100 grams per pot (6.2 tons per hectare) and 50 percent of the recommended chemical fertilizer application gave a significantly higher yield (15 percent more) of eggplant fruits, compared to that with 100 percent chemical fertilization, after 120 days from planting.
Similarly, in another experiment with upland rice in plastic containers, results indicated that use of vermicompost at 0.5 kilogram per square meter (5 tons per hectare) and 50 percent of the recommended chemical fertilizer gave a significantly higher yield (20 percent more) of rough rice, compared to that with 100 percent chemical fertilization, after 123 days from planting.
“Intestines of the soil” was how Aristotle called earthworms while Cleopatra decreed them sacred. “It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly, organized creatures,” Charles Darwin stated. The Chinese character for earthworms translates as “angels of the earth.” — ###