“Carbon Footprint” is a term known to most of us, but have you ever heard of the “Nitrogen Footprint”? Agriculture provides humans beings with food to survive. Using nitrogenous fertilizer can increase the yield, but overfertilization leads to eutrophication and increased greenhouse gases.
Ming-Chien Su, the vice dean of the College of Environmental Studies and director of the Environmental Fate Studies Lab of National Dong Hwa University, is committed to environmental management. She accepted the exclusive interview with the MOST Center for Global Affairs and Science Engagement and shared how the lab’s research team made an arduous journey to conduct environmental monitoring and assist the government in formulating sustainable agricultural policies.
From Mountains to Seas, Data Tell the Environment’s Fortune
Tourists coming to Eastern Taiwan must journey up to the mountains and down to the seas to enjoy different natural sceneries. Driving an off-road vehicle, Su traveled from Taroko National Park (over 3,000 meters above sea level) to the estuary (close to sea level). She carried heavy monitoring over 10 kg and sampling pieces of equipment, including soil, water, and sediment samplers and greenhouse gas emission monitor instrument for environmental measurement.
Su explained that studying the so-called “environmental fate” is to “tell the fortune” of the environment. Using the monitored data of various pollutants, the research team estimates the distribution of the pollutants by analyzing the environmental carrying capacity to take into account environmental protection and economic development.
The Environmental Fate Studies Lab, established in 2002, is dedicated to studying the long-range transport of environmental pollutants, performing ecology risk assessments and management, and monitoring the environmental quality of farmlands and sediment pollutants in port areas. Its team members conduct model analyses of various environmental monitoring data to assessing the impacts on human health and ecology and provide references for policymaking and management.
Rational Fertilization Helps Reduce the Nitrogen Footprint
Su returned from the United States to teach in Taiwan in 1999. At that time, Taiwan’s environmental research was focused on the field of industrial pollution. She started teaching at National Dong Hwa University in 2002.
Agriculture is the major economic activity in eastern Taiwan. Traditionally, it is believed that agriculture does not pollute the environment. Still, overfertilization will cause a large amount of nitrogenous fertilizer left in the soil to be washed away, resulting in severe water pollution and the emission of greenhouse gases. Studies abroad have found that 50% of the nitrogenous fertilizer cannot be absorbed by plants and is scattered. Therefore, the Council of Agriculture has been promoting “rational fertilization” for many years.
Su once selected three farmlands in Shoufeng Township, Hualian County, for a field study. She compared the effects of three different fertilization methods on greenhouse gas emissions. Since fertilizers are not used in natural farming, the level of greenhouse gases detected was the lowest for this type of farming. Surprisingly, in the next year, the natural farming harvest was higher than that of the control group (conventional agriculture).
Su said that the excessive use of chemical fertilizers would cause environmental pollution and reduce the capacity of the soil to hold water and fertilizer. For farmers, it means that the increase in production costs does not necessarily result in better yields. Therefore, the above experimental data can be used as supporting evidence for the government to promote rational fertilization.
In addition, the Environmental Fate Studies Lab also studies animal manure compost management. Su pointed out that more than 100 million chickens are currently being raised in Taiwan. The methane released by chicken manure has been proven to be 20 times higher than carbon dioxide in terms of the greenhouse effect. In the past, farmers used raw chicken manure for compost, but improper processing of raw chicken manure causes environmental pollution, produces odors, and even attracts flies that breed. In the hot summer temperatures, the odor is even more intense, affecting residents’ living quality.
Over the past decade, the Environmental Fate Studies Lab has referred to the current EU management practice and assisted the government in formulating relevant regulations for converting animal waste to energy. Beginning this year, Hualian County has banned farmers from using raw chicken manure as a fertilizer.
Converting Manure into Green Fertilizer by Learning from Others
Su said that Taiwan actually imports a large amount of chicken manure fertilizer each year. Suppose that local chicken manure can be pre-processed, recycled, and dried into organic fertilizer using technology. In that case, not only would recycling be performed, but exporting to Southeast Asia (business opportunities) could also be expected.
Su takes Germany’s animal biogas resource recycling as an example. She participated in the 2016 International Biogas Symposium held in Germany; there, she learned of a small local cattle farm that cooperated with a biogas power plant to convert thousands of tons of cow dung into green biogas for power generation using technology. This effort not only reduced the workforce required to deal with odorous waste, but the energy generated could also be used by the farm. Furthermore, the remaining electricity could be sold back to the biogas plant. The power plant further assisted the farm by preparing nutritious feed for cattle. In the end, the farm owner became a shareholder in the power plant and began receiving dividends each year.
The farm owner’s words that impressed Su the most were, “when my child goes to school, he no longer has the odor of cow dung and is not laughed at by others!” From these international success stories of green energy, Su believes that Taiwan, the technology island, can achieve the goal of waste utilization, and the added value of agricultural products can be increased.
Su feels that in the past, everyone thought that environmental protection and the economy were in conflict, but from the agricultural economy’s perspective, the two truly complement each other. If the quality of the environment is good, the benefits of agriculture will increase. Although Hualien cannot keep up with Taiwan’s industrial development, the unpolluted ecological environment with abundant tourism resources is ideal for developing sustainable agriculture and achieving the sustainable development goals of the United Nations.