Chemical Fertilizer in Agriculture: A big source of Greenhouse Gas Emissions

In the present day, human behaviour is leading to one of the world’s biggest issues. We are producing a huge amount of greenhouse gases. The atmosphere contains many types of greenhouse gases. The major greenhouse gases are carbon dioxide, methane, nitrous oxide, and industrial gases. Greenhouse gases trap heat from the sun inside the Earth’s atmosphere, making the Earth warmer and causing climate change. This affects the environment, wildlife, and human health. The major human activities that release greenhouse gases are agriculture, particularly chemical fertilizer in agriculture, as well as transportation and industry.

Greenhouse Gas Emissions from Land Use and Chemical Fertilizer in Agriculture

Our lives revolve around livestock and food from the agriculture sector. Research shows that agriculture contributes about 15% of global greenhouse emissions. Agriculture emits all three major greenhouse gases: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Methane traps heat at a rate 25 times higher than carbon dioxide, while nitrous oxide traps heat 298 times higher. Because nitrous oxide has the greatest heat-trapping potential, we must focus on the nitrogen (N) sources released in agriculture. Organic and chemical fertilizer in agriculture are the main sources of nitrogen, and they play a crucial role in crop growth. Although they generate direct and indirect greenhouse gas emissions, we cannot stop using fertilizers because plants rely on them for essential nutrients.

Figure 1: Evolution of net GHG emissions from 1990 to 2019. agriculture also emits Methane (44% of anthropogenic emissions) and Nitrous oxide (80% of anthropogenic emissions)

Current fertilizer practices in Thailand

In Thailand, many sugarcane farmers rely on chemical fertilizers because they cost less and provide sufficient nutrients. However, most farmers lack the knowledge to use them effectively. Optimizing the ratio and type of fertilizer can reduce costs and pollution. Soil analysis helps determine the right fertilizer ratio based on chemical properties such as nutrient levels, ion exchange capacity, pH, and microbial presence. Although this method is useful, farmers often find it difficult because they must send soil samples to analysis centers.

Nitrogen-fixing plants, like beans and legumes, also boost nitrogen levels in the soil. Authorities now encourage farmers to apply specific N-P-K portions according to local soil conditions. Overusing chemical fertilizers can leave residues in crops that may transform into carcinogenic compounds within the human body. By following recommended fertilizer portions, farmers protect both the environment and public health.

Fairagora Asia’s Project: Reducing Chemical Fertilizer in Agriculture

In 2021, Fairagora Asia is launching the Smallholders Impact Project which mainly focuses on environmental impact and social aspects in sugarcane farming in Thailand. Many activities in sugarcane cultivation create greenhouse gas emissions, for example, sugarcane burning, fertilizer use, fossil fuel and irrigation. Chemical fertilizer is playing a big role for N2O production. A huge amount of N2O is produced by nitrogen in the soil by applying excess fertilizer. In this project, we are using technology to create a solution. VerifiK8 is the technological tool used to monitor all data in the farm. We implement the mitigation activities to reduce greenhouse gas emission related to fertilizer use, e.g. optimize the amount use of organic and chemical fertilizer, water system and soil analysis. We will monitor the data yearly to see the improvement of carbon footprint and other environmental impacts.