‘Super grass’ suppresses greenhouse emissions

Kyodo

Researchers from Japan and Colombia have developed a “super pasture grass” enabling suppression of greenhouse gas emissions and enhancing cattle breeding.

The researchers discovered an inhibitor called brachialactone, released from the roots of a tropical grass, that can minimize greenhouse gas emissions from soil caused by use of chemical fertilizers. The inhibitor prevents conversion of the fertilizer components into greenhouse gases, some of which are believed to cause soil and groundwater contamination, according to the study results.

The project was conducted by researchers at Japan International Research Center for Agricultural Sciences (JIRCAS) based in Tsukuba, Ibaraki Prefecture, and the International Center for Tropical Agriculture, known as CIAT, based in Cali, Colombia. CIAT is an acronym for its Spanish name, Centro Internacional de Agricultura Tropical.

The scientists expect that introduction of the new grass will help reduce emissions of greenhouse gases from the agriculture sector, estimated at more than 10 percent of such emissions.

Among chemical fertilizers, scientists point out that nitrogen-applied fertilizers widely used in crop cultivation are mainly responsible for the greenhouse gas emissions.

Due to microbial activity in the soil, nitrogen is converted into nitric acid, part of which can then be converted into nitrous oxide gas, which warms the planet 300 times more powerfully than carbon dioxide. Nitric acid, which is susceptible to evaporation in the soil, is believed to be responsible for contamination of groundwater, which in result can cause eutrophication of rivers and oceans. This stimulates the growth of aquatic plant life, usually resulting in the depletion of dissolved oxygen.

The researchers at JIRCAS and CIAT have found that the inhibitor, found in the brachiaria or signal grass mainly cultivated in Africa, may reduce the microbial activity enabling reduction of the greenhouse gas emissions to one-tenth. Brachiaria is also widely used in South America. By interbreeding the grass with related species the scientists managed to develop a type of grass of highly nutritive value.

The results of an experiment conducted with the use of the new type of grass have shown that not only was the nitrous oxide emission suppressed, but production of milk and beef also improved.