Rice terraces earthworms as animal feed

BANAUE, Ifugao – Farmers here have welcomed a government project that aims to eradicate or control giant earthworms that have for years been destroying the world-famous rice terraces in the Cordillera.

The project, titled "Assessment and Utilization of Earthworms in Banaue Rice Terraces," is a joint undertaking of the Philippine Rice Research Institute (PhilRice) and the Los Baños-based Department of Science and Technology-Philippine Council for Aquatic and Marine Research and Development (DOST-PCAMRD).

A memorandum of agreement (MOA) for the implementation of the project had earlier been signed between PhilRice, represented by Executive Director Leocadio S. Sebastian and PCAMRD, headed by Executive Director Rafael D. Guerrero III.

Witnesses to the signing of the agreement were PhilRice Deputy Executive Director Edilberto Redoña and senior research fellow Dr. Ravindra Joshi and PCAMRD Deputy Executive Director Cesar Pagdilao.

The project will assess the productivity of the earthworms, utilize the annelids gathered for animal and fish feeds, and reduce the damage to the terraced walls.

Dr. Joshi told The STAR that farmers in the terraces will be tapped to collect the earthworms, which will be bought by the project and processed into animal and fish meals (vermimeal).

"Vermimeal is a rich source of animal protein," said Dr. Guerrero. The Philippines imports $35 million of fish meal annually for its animal and fishfarming industries.

Dr. Joshi reported that ways of flushing out the earthworms from the soil without resorting to digging are now being studied. He noted that during the hot months, the earthworms burrow deeper into the soil.

Over the years, giant earthworms "alien" to the Cordillera have been considerably damaging the terraced farms, particularly those in Banaue, Hungduan and Mayoyao.

Studies so far done by PhilRice and the Department of Agriculture (DA) have shown that the soil creatures tear down the earthen support of the rice terraces by slithering through the paddies’ walls. When submerged in water, the terraces collapse, resulting in its disappearance.

The research team composed of Dr. Joshi, Olive Rose Matchoc and Fe dela Peña, all of PhilRice and Raymundo Bahatan of DA noted two types of earthworms found in the terraces.

The researchers had tagged them as Species I and II until further scientific findings.

Species I are shallow soil dwellers, living in the top 12 inches of soil. The adults are three to seven inches long and five millimeters thick.

Species are deep burrowers. Adults are 10-20 inches long with a diameter of a man’s index finger.

Dr. Joshi and Jaime Cabigat of DA subsequently sent samples of the subterranean creatures they had gathered to taxonomists in the Philippines and countries in Asia and Europe and in the United States.

Two of those who responded – Dr. A. Ziesi, emeritus professor, and Dr. Cs. Csuzdi, both of the Eotvos Lerand University in Budapest, Hungary – confirmed that some of the giant earthworms destroying the rice terraces were "alien" to the Cordillera.