Dr. Nelly S. Aggangan (center), Scientist I at UPLB-BIOTECH and NRCP researcher, poses with her research team after conducting field experiments at Brgy. Capayang, Mogpog, Marinduque (credits to Dr. Aggangan).
With the recent turn of events in the mining sector, one scientist is finding ways to restore degraded mining sites using soil microbes such as fungi and bacteria.
Dr. Nelly Aggangan, National Research Council of the Philippines (NRCP) researcher based at the University of the Philippines Los Baños (UPLB), is developing methods to help restore degraded and abandoned mining sites in Marinduque.
The researcher uses native plants and their associated microbes of fungi and bacteria to help clean and restore the environment in a process called bioremediation. Adding soil microbes cause increase in height, stem diameter, and survival of plants in hostile mining environments.
In recent months, the mining sector has been put on the spotlight with the closure of several mines in the country by the Department of Environment and Natural Resources.
Mining sites: degraded and abandoned
While mining products are basic ingredients of our everyday lives, mining is often often perceived to be destructive to the environment. Mining sites, either mined-out or affected by mine tailings, are normally devoid of plants due to the toxic effects of heavy metals and the infertile state of the soil. Further, the soil lacks biological activities with very low nitrogen, an essential nutrient for plant growth, making it hard for plants to re-establish in the affected areas.
Such is the state of the researcher’s study area in Brgy. Capayang, Mogpog, Marinduque with lands that were left unattended since 1996 after extracting Copper metal from rocks and soils.
Hope for mining sites
All is not lost. There is still hope for these degraded mining areas as scientists continue to work on bioremediation. Through this process, native plants are able to re-establish using associated microbes in their root systems. By adding nitrogen-fixing bacteria and mycorrhizal fungi, commonly called biofertilizers, the host plant’s absorption of water and nutrients is enhanced. Tolerance to high levels of toxic metals such as copper is also increased.
Dr. Aggangan used biofertilizers developed by UPLB National Institute of Molecular Biology and Biotechnology (BIOTECH) as soil amendments together with compost and lime. Naturally occurring soil microbes in the area were also isolated for future testing as native microbes are known to be more effective as observed in other studies.
Acacia mangium plants with (left) and (without) soil amendments. Young acacia plants with soil amendments grew more than those without (credits to Dr. Aggangan).
Initial results of the on-going NRCP-funded project have been nothing short of promising. The addition of lime, compost, mycorrhizal fungi and nitrogen-fixing bacteria alone or in combination has greatly improved the growth of narra, acacia and eucalyptus plants in the area. In one experiment, an average of 41% increase in height and 35% increase in stem diameter have been observed for narra after just 7 months.
Dr. Aggangan hopes to develop the best bioremediation protocols in Mogpog, Marinduque that would also be applicable to other mining sites with similar disturbances in the country. In the future, her research on biofertilizers and bioremediation could be the hope for accelerating rehabilitation in mining-damaged sites.
Dr. Aggangan presented updates on her study during the Division of Agriculture and Forestry meeting of NRCP last March 9, 2016 at UPLB.
- Written by Erwin Don R. Racasa
- Published: 14 March 2017