Bamboo, vetiver effective in riverbank rehab – study

LOS BAÑOS, Laguna – Two plant species have been found effective in rehabilitating degraded riverbanks.

Bamboo (bayog) and vetiver (Vetiveria zizanoides) can control soil erosion and rehabilitate riverbanks, according to a study done by researchers Marlowe Fajanil, Leonardo Yraula and Ernesto Arevalo of the Department of Environment and Natural Resources (DENR)-Region 6 (Western Visayas).

“Bayog, in combination with vetiver, is the best treatment for critical riverbanks. The combination can also help in soil buildup and improve the stability of the river systems,” the researchers said.

Vetiver is a fast-growing perennial grass that can reach a height of one meter or more. It has a massive root system that can provide the structural strength to minimize soil erosion.

This “miracle grass” is known in various parts of the country as ilib, mora, moras, moro, muda and giron.

Vetiver’s extensive and thick root system, which reaches two to three meters deep, binds the soil, making it difficult to be dislodged by the force of wind and rain, according to another study done by the Visayas State University (VSU) in Baybay City, Leyte.

Moreover, the VSU said the grass species does not compete with the main crops because it grows straight down and does not spread sideways.

Conducted in Cuatero, Capiz, the DENR-Region 6 research project was monitored by the Los Baños-based Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCARRD).

In the study, Fajanil, Yraula and Arevalo used two species of bamboo: bayog (Bambusa blumeana var. luzonensis) and botong (Gigantochloa levis) and combined them with vetiver to find out how well they could rehabilitate critical riverbanks.

Vetiver grass used in the research was gathered in ricefields in Antique, while the bamboo planting materials were sourced from Antique and Capiz.

The bamboo species were planted in two strips, two meters apart inland, adjacent to two strips of vetiver grass which were two meters wide, with rows one meter apart. They were planted right above the waterline.

“Cheap and easy to establish, vetiver hodges are easy to maintain and serve as good barrier for soil erosion,” reported the DENR researchers, as documented by PCARRD’s Dr. Leida America.

“A well-protected and stable riverbank protects nearby agricultural lands from damage caused by floods,” they said.