Excess nitrogen spoils biofuels

Journal name:
Date published:
Published online

Nitrogen fertilizer can boost the growth of crops for biofuel production, but applying too much can cut the climate benefits in half.

Ethanol fuel made from plant cellulose is a promising form of renewable energy. Philip Robertson at Michigan State University in Hickory Corners and his colleagues applied various amounts of nitrogen fertilizer to experimental plots of switchgrass (Panicum virgatum) for three years. They measured emissions of the greenhouse gas nitrous oxide (N2O) and the leaching of nitrate, a water pollutant. The authors found that fertilizer boosted yields in the first year, but that the increase declined with subsequent applications. Levels of both emissions and leaching grew exponentially with increases in fertilizer.

The team suggests that minimizing fertilizer use will be crucial for maintaining the environmental benefits of cellulosic biofuel.

Environ. Res. Lett. 11, 064007 (2016)


  1. Report this comment #68215

    Chandrika Tilakarathna said:

    Chemical fertilizers cut down by 50%

    In Sri Lanka, all NPK applied as chemical fertilizers have been cut down by 50% for rice cultivation, yet we have achieved up to 40% yield increase, when a novel biofertilizer called Biofilm biofertilizers are coupled with the 50% chemical fertilizers. N2O emission has also been reduced consequently, as was measured in some other crops. For rice, this was introduced only in January 2016. By now, the Biofilm biofertilizer is used for about 1,500 acres of rice cultivation with good results.

    Gamini Seneviratne PhD., Research Professor in Microbial Biotechnology, National Institute of Fundamental Studies (NIFS), Hantana Road, Kandy, Sri Lanka. Tel.: 94 81 2232002, Fax: 94 81 2232131, E-mail:, Web:
    Ministry of Science, Technology & Research

Subscribe to comments

Additional data