Fertilizer use and climate change. Unfortunately, choice words you rarely hear used in the same sentence. With so much focus given to emissions from transportation and industry, lesser known, but equally important factors like fertilizer use are often overlooked. To place things in perspective, the overuse of fertilizers releases an estimated 2 billion tonnes of nitrous oxide (a GHG estimated to be 300 times more potent than carbon dioxide) into the atmosphere annually. What is also alarming is that agricultural activities in general contribute to 17 to 32 per cent of global GHG emissions. And with the majority of these agricultural activities requiring fertilizers in one form or another, it’s clear their use must be examined closely.
So how do we minimize GHG emissions but still maximize fertilizer potential? Finding an easy solution is certainly no walk in the park. Farmers will not only have to be educated on the best management practices (BMPs) for fertilizer use, but these BMPs will have to be tailored for general crop types and climatic conditions. For example, BMPs for nitrogen fertilizer used to grow corn in Mississippi should be quite different from those used to grow wheat in Iowa. Regrettably, this makes creating a national framework for fertilizer use a difficult task.
One proposed solution that has come under intense scrutiny within the past decade is the use of a fertilizer tax. The objective of this practice is to encourage conservative use of fertilizers, simply by making them more expensive. Not only has this system proven to have logistical flaws, but the last thing we want to do is place yet another burden on the pocketbooks of farmers. A recent analysis of European research found that “over the last 20 years in Europe, the price of nitrogen fertilizers has weakly influenced its consumption trends” (Lacroix & Mollard, 2004). The general conclusion of the study being, that taxation was unable to reverse the pull of agricultural production. How then should we be targeting the problem? Here are just a few suggestions.
Improved land-use management and BMPs that restore organic soils are a must. For example, by cycling leguminous crops into a farmers’ arsenal, valuable nitrogen is put back into the soil, allowing less fertilizer to be used in the next season. While this is not a realistic solution for all crops or conditions, it’s certainly a practice that is still undervalued.
It is also crucial for each country, and potentially each state or province, to develop a nitrogen fertilizer use protocol. These protocols should incorporate guidelines and BMPs for the use of the correct fertilizer product for each crop type, at the right time, place, and rate. Only by enforcing the use of such protocols would we be able to increase proper nitrogen fertilizer use at the national and regional levels. Other BMP strategies that have proven successful under certain conditions include; increasing the number of crops under no-till agriculture, reducing fertilizer application rates, adding fertilizer in the fall rather than the spring, and increasing permanent cover acreages.
It’s time to start addressing this serious issue of nitrogen fertilizer use and greenhouse gas emissions. We can no longer simply regard this as a “farmer’s problem”. Individuals at all levels need to promote BMPs for fertilizer use, rather than the strict, draconian regulations of the past, that will all too often be labelled unrealistic and unwarranted by the agricultural sector.
ClimateCHECK is a greenhouse gas (GHG) management services and solutions company. The firm’s solutions support all facets of the carbon commodities market, including the verification, validation and consultation of GHG inventories and program portfolios, as well as quantification protocols for emissions reduction projects and clean technologies. ClimateCHECK is a sponsor and co-founded, with World Resources Institute and Carbon Disclosure Project, the Greenhouse Gas Management Institute (www.ghginstitute.org). Founded in March 2007, the company has locations throughout North America. For more information visit www.climate-check.com.