Bamboo and Vetiver as Rehabilitation Materials for Critical Riverbanks

Riverbanks play an important role in the lives of the people and the communities around it.  A well-protected and stable riverbank protects the nearby agricultural land and crops from damage during flood.  Moreover, rivers with good banks can be used for recreation, navigation, fishing and others.

Due to the wanton destruction of forests and improper land use practices, most riverbanks become unstable and are now in critical condition.  Hence, there is a need to rehabilitate these riverbanks to address the problem of stream bank erosion and instability.

The Author assessing the damage on the banks of Morong River in San Guillermo during the aftermath of "Habagat" in 2012.  Many portions of its riverbank are now in critical condition and needing rehabilitation.

Fajanil et al. (DENR 6) conducted a study from 2002 to 2005 to find out the suitability of bamboo and vetiver in rehabilitating critical riverbanks in Cuartero, Capiz.  Previous reports showed that these two species have great potential to control soil erosion and can be used to stabilize riverbanks, hence they were used in the study.

The researchers used botong (Gigantochloa levis) + vetiver grass; bayog (Bambusa blumeana var. luzonensis) + vetiver; and control (no bamboo) -vetiver grass.  The outplanted bamboo and vetiver grass were properly protected and maintained.  Periodic weeding, brushing and fertilization were done to enhance their growth.
Findings

• Bayog + vetiver grass performed best in terms of growth performance, number of vetiver tillers, and soil build-up.
• In terms of height and number of clumps of the vetiver, there were no significant difference among treatment means.
• In 2004, botong had an average of 8.5 poles/clump with an average of 5.3 shoots/clump.  Likewise, bayog in 2004, had an average of 7.85 poles and 4.42 shoots while in 2005, it had an average of 30.3 poles and 6.2 shoots.  These indicated that inter-planting of bamboos with vetiver enhances bamboo pole and shoot production.

The researchers recommended that bayog in combination with vetiver be planted along riverbanks to control soil erosion.  Furthermore, it was recommended that other bamboo species in combination with vetiver be also studied.

Source: Philippine Council for Agriculture, Forestry and Natural Resources Research and Development.  Highlights 2006. Los Baños, Laguna:  PCARRD, 2007. 204p. Post originally appeared in pcaarrd/DOST site in April 21, 2008.