Fertilizers play two essential roles in the fight against climate change
First, they forestall deforestation, as they allow for increased productivity on arable land. They help maintain the integrity of globe’s forests, which are important carbon sinks. In the context of climate change, this is crucial, as deforestation and loss of peatlands, wetlands and grasslands combined represent about 10% of global GHG emissions, not to mention considerable damages to the ecosystem. Sustainable intensification of agriculture productivity on arable land has alreadymanaged to preserve 1 billion hectares of land between 1961-2005 , and more can be achieved through the implementation of best management practices in fertilizer use.
Second, they also increase the carbon sequestration potential of agricultural soils by contributing to their building up of soil organic matter (SOM). SOM importantly facilitates higher nutrient uptake by plants, and increased plant growth absorbs more CO2 from the atmosphere. Soils deserve special attention – they can store up to 50-300 tonnes of carbon per hectare, which is equivalent to 180-1100 tons of CO2. 89% of agriculture’s future mitigation potential is based on soil carbon sequestration. Carbon sequestration in cultivated soils can be increased by adding appropriate organic and mineral nutrients for biomass production, as well as by reducing tillage, and using cover crops. In order to maximize carbon sequestration in soil organic matter, the fertilizer industry advocates for the integrated use of available plant nutrients (organic and inorganic) to improve crop and biomass production.
Adapting to climate change through Fertilizer Best Management Practices
The agricultural sector is one of the most vulnerable to climate change, and its negative effects (such as extreme weather events, increasing temperatures, declining availability of water and other resources) have started to severely impact agricultural livelihoods in many regions.
Site-specific nutrient management allows for a correct fertilization of plants that helps boost their health, and their resilience to climate stress. Healthy soils and plants can better withstand climate stress and also contribute to greater water use efficiency. Moreover, it will be vital for farmers to maximize their yields in good seasons to make up for potentially more severe weather events.
Site-specific nutrient management practices optimize product efficacy and minimize nutrient losses to the environment. The 4Rs Principles are the core of these best management practices.
The 4Rs entail using the Right fertilizer source at the Right rate, Right time and Right place so that fertilizer application can be managed to achieve economic, social and environmental goals. The 4Rs are applied throughout the world, in developed, developing and emerging economies.
Conservation practices (such as crop rotation, reduced tillage, mulching and cover cropping) can increase soil resilience by reducing soil erosion and water evaporation, while stream buffers and wetlands contribute to filtering surface water. Combining them with 4R nutrient stewardship (“4R Plus”) is starting to show very good results in conserving humidity in soils, and reducing nutrient losses to the environment while boosting productivity.
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.
It is also vital to keep in mind that whereas GHGs are emitted during fertilizer production and application, much greater GHG savings are made as a result of enhanced crop productivity through the use of fertilizers: In sub-Saharan Africa (the region with the lowest fertilizer consumption in the world), a 20% increase of fertilizer use could result in more than 2 million hectares of land spared, and up to 13 million tons of carbon sequestered compared to 0.4 million tons emitted (IPNI, 2018).
Reducing emissions from fertilizer production
GHG emissions related to fertilizer production represent approximately 1% of total global GHG emissions. This can be considered a negligible amount, considering that global agricultural input would be reduced by 50% without the use of mineral fertilizers. But the industry is also committed to reducing its production-related GHG emissions. IFA members are thus regularly invited to participate to IFA’s benchmarks to track their energy efficiency performance and GHG emissions: IFA Energy Efficiency & CO2 Emissions Report and the IFA Environmental report.
Courtesy: International Fertilizer Association