Towards zero-emission agriculture: Development and dissemination of technologies to mitigate greenhouse gas emissions with enhanced agricultural productivity

National Agriculture and Food Research Organization (NARO)

Outline

National Agriculture and Food Research Organization (NARO) addresses global and domestic climate change issues in the agricultural sector on three dimensions: Impact assessment, adaptation and mitigation. Towards zero-emission agriculture, NARO will take on the challenge of developing and disseminating the following technologies to reduce greenhouse gas emissions with enhanced agricultural productivity.

Mitigation technologies that enable drastic reductions in greenhouse gas (CH4 and N2O) emissions from farmland and livestock
Soil management practices for increasing soil carbon storage in farmland by practices such as applying biochar and/or organic amendments to agricultural soils for reducing atmospheric CO₂ concentrations
A smart energy management system for renewable and self-sufficient rural energy use to reduce reliance on fossil fuels

Description

Globally, the Agriculture, Forestry and Other Land Use sector contributes to 24% of anthropogenic greenhouse gas emissions mainly from agriculture (soil, livestock and nutrient management) and deforestation (IPCC-AR5-WGIII, 2014, Climate Change 2014 Mitigation of Climate Change). In Japan, the agriculture sector contributes to approximately 4% of total domestic greenhouse gas emissions (Fiscal year 2017, approximately 50 million ton of CO₂-equivalent greenhouse gas emission including fuel consumption-derived CO₂ emissions from agricultural machinery and facilities). Thus, agriculture has a significant impact on climate change as a major source of greenhouse gases (mainly CO₂, CH4 and N2O) to the atmosphere.

Reductions in CH4 and N2O emissions from farmland and livestock

Greenhouse gas emissions from agriculture include CH4 emission from paddy fields where rice is grown, N2O emission from farmland soil (as a result of nitrogen fertilizer and animal manure application), CH4 emission from ruminants (mainly cattle and sheep), CH4 and N2O emission from animal waste management. CH4 and N2O are the potent greenhouse gases that have global warming potentials of 25 and 298, respectively, relative to CO₂. Emissions of these non-CO₂ greenhouse gases in agriculture are derived mainly from microorganisms living in soil, ruminants and animal wastes and stand for greenhouse gas emissions from agriculture. NARO has developed mitigation technologies to reduce CH4 emissions from paddy field by prolonging midseason drainage and to reduce N2O emissions from wastewaters in swine farming by using carbon fiber reactors. Recently, NARO started to work on developing new cattle lines or rice varieties with less CH4 emissions.

Enhancing soil carbon storage in agricultural land (Reduction in atmospheric CO2 concentrations)

Soils accumulate large amounts of carbon in a form of soil organic matter. On a global scale, the quantity of carbon in the soil is about 2 times greater than that in the atmosphere and about 3 times greater than that in the vegetation in terrestrial areas. Once biomass such as animal manures, green manures and crop residues are incorporated into the agricultural soil, a portion of the biomass is converted to recalcitrant soil organic matter and then carbon derived from the biomass is stored in the soil. This is called “Soil carbon storage in agricultural land”. Because all carbon components in the biomass is derived from CO₂ in the atmosphere, “Soil carbon storage in agricultural land” contributes to reductions in CO₂ concentrations in the atmosphere. Recently, biochar (biomass-derived charcoal) is drawing attention because it is quite resistant to decomposition in soil and therefore enhances the efficiency of soil carbon storage.

Establishing smart renewable energy-based energy management systems

There are ample renewable energy resources in rural areas. These includes small-scale hydro-electric generation using water utilization system (i.e., irrigation system), CH4 generation through anaerobic digestion of biomass resources such as animal wastes, food processing wastes and crop residues, and utilization of heat energy in the ground available for air conditioning in greenhouses as well as solar and wind power generation. The energy generated from different sources is managed in the form of electricity and hydrogen within the energy management system and consumed for various activities in rural areas such as agricultural production and daily activities. Excess energy can be temporarily converted to potential energy by pumping up water. These smart energy management systems allow us to reduce large dependence on fossil energy and also to reduce CO₂ emissions significantly in rural areas. Application of pelletized biomass from fast-growing or high carbon-fixing plants for heating greenhouses and use of electricity or hydrogen for agricultural machinery in place of diesel fuels can also contribute to reduction of CO₂ emissions from fossil fuel consumption.

International contributions

NARO has been leading the world in developing mitigation technologies for reducing CH4 emissions from paddy fields particularly prevailing in Asian countries, for example, water management practices that enable to save irrigation water and to reduce CH4 emissions from paddy soils simultaneously. In addition, Japan is one of the few countries that take into account the CO₂ sink by soil carbon storage for the national greenhouse gas inventory. The highest tier methodology (Tier 3) based on soil carbon dynamics models developed by NARO is used in the Japanese national greenhouse gas inventory.

Challenges

NARO declares challenges to develop management practices for crop and livestock farming that enable both to enhance agricultural productivity and to reduce greenhouse gas emissions. NARO is also going to implement such management practices widely for Japan and the world in collaboration with government, industry and academia to contribute to great reductions of greenhouse gas emissions.

Partner(s)

NARO would like to work together with companies interested in climate-smart technologies and/or agricultural and livestock products. NARO is also well-prepared to cooperate with companies interested in CSR activities and ESG investment in the agriculture sector.