Carbon nanoparticles in 'biochar' boost wheat (Triticum aestivum) plant growth
Manav Saxena, Sheli Maity and Sabyasachi Sarkar
Department of Chemistry, Indian Institute of Engineering Science and Technology Shibpur, Howrah-711103, India
Biochar is shown to contain raw carbon nanoparticles (rCNPs). Traditional use of this for the healthy growth of the plant is due to its retention capability of nutrients for the need based slow release. On aging rCNPs get oxidized with the incorporation of hydrophilic carboxylic and hydroxyl groups on its surface to increase its spongy structure to absorb more water and several ionic nutrients. Chemical oxidation of rCNPs in biochar introduced similar carboxylic acid and hydroxyl groups in transforming rCNPs to water soluble carbon nanoparticles (wsCNPs). This wsCNPs in solution enhances the growth rate of the wheat plants. The concentration of wsCNPs used in this wheat plant growth study is varied in the range from 10 to 150 mg/L. The seeds treated with wsCNPs in this range show higher growth rate where the optimum growth is found with 50 mg/L as compared with the control study. This suggests a concentration threshold of wsCNPs for the optimum stimulation in plant growth which the aged biochar can readily meet. Model experiments with ammonium nitrate as cationic and anionic nutrients show that both the rCNPs and wsCNPs hold the nutrient ions albeit the negatively charged wsCNPs hold less effectively the anionic nitrate. These carbon nano particles are capable to release cationic and anionic nutrients slowly with time. Such action is correlated with the booster action of CNPs in supplying nutrients to the young plants. Thus wsCNPs can be a better choice than fertilizer or manure alone by its controlled and slow release of nutrients for better assimilation by plants.
Links to the paper: http://pubs.rsc.org/en/Content/ArticleLanding/2014/RA/C4RA06535B#!divAbstract