Reducing emissions from fertilizer application
When considering GHG emissions from fertilizer use, the focus should be on relative emissions of agricultural crops grown with the assistance of fertilizers. Zero losses are not an achievable goal given that we are dealing with natural biological processes; but it is important for plant nutrient sources to be carefully managed and applied according to crop- and site-specific needs to achieve the “triple wins” of food security, environmental protection, and climate change adaptation and mitigation.
Nutrient use efficiency i.e., the proportion of nutrients applied from all sources that are taken up by the crop, is a useful indicator the efficiency of fertilizer management, while minimizing environmental losses. Low output/input ratios often reflect risks of nutrient losses to the environment, while high ratios, above 100 percent, reflect soil nutrient mining practices that reduce soil fertility if practiced over several years. Both cases are unsustainable.
The fertilizer industry therefore promotes the science-based Principles of 4R Nutrient Stewardship (Right Nutrient Source, at the Right Rate, at the Right Time, in the Right Place), as they match nutrient supply with crop requirements to optimize yields while minimizing losses to the environment.
Understanding and Managing Nitrous Oxide Emissions from Agricultural Soils
15 January 2021