Jatropha curcas can be safely planted with other crops, research shows

Farming for biofuels can be a profitable farming endeavor because of the ever increasing cost and demands for fossil fuels the world over.  It also presents other benefits to farmers as it can optimize the use of marginal lands, which are unproductive and underutilized for food production.

One of the most promising plants for biofuel farming is Jatropha curcas, locally known as ‘tubang bakod’.  J. curcas is fast becoming the most promising biofuel source with its reported more than 30% oil yiel.  Jatropha methyl ester (JME) was also found to be better than that of fossil fuel diesel and safer for the environment.

However, farmers and other concerned stakeholders of biofuel farming have been apprehensive about the danger of planting J. curcas alongside other crops as it might do harm to useful soil microbes or microorganisms that can contribute to agricultural productivity.  Useful microbes promote plant growth and development, protect crops from pests and diseases, and improve soil water retention.

According to a report, plant-based substances released by the various parts of J. curcas such as its leaves and roots produce allelophatic substance that has negative effects to soil bacteria along with other beneficial microbes such as Rhizobium and Vesicular Arbuscular Mycorrhiza (VAM) fungi, among others.

Therefore, researchers of the University of the Philippines Los Baños (UPLB) conducted a research study titled “Jatropha curcas: Impact on soil microbial relationship of the said components to determine the impacts of J. curcas on soil microbial populations and its response to mycorrhizal inoculation.

Findings of the study as reported to the Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCARRD), revealed the impacts of J. curcas on major functional soil microbes (bacteria, fungi, and mycorrhiza) and jatropha’s responsiveness to beneficial soil microbes (VAM mycorrhiza fungi).

The study proved that jatropha did not hamper the production of functional groups of aerobic (those that can grow or live only in the presence of free oxygen), heterotrophs (organisms which feed on others), free-living nitrogen fixers, and pseudomonads microbes.

Also, the study showed that majority of data on microbial density comparisons indicate that J. curcas is not detrimental to most of the microorganisms examined.  Some results showed higher number of bacteria, other functional groups and fungi in Jatropha-planted soil and even stimulated VAM fungi sporulation under field conditions.

Further, J. curcas did not have any deleterious effect on mycorrhiza, one of the most beneficial soil microbes as exhibited by high percent root colonization and positive growth of J. curcas to VAM inoculation.

With these findings, the researchers said that the ability of J. curcas to thrive in poor conditions while simultaneously promoting mycorrhizal proliferation and other beneficial microbes in soil are the qualities that make J. curcas fit for biofuels production.  Bengie P. Gibe, S&T Media Service