Rome, 15 November 2022 – How much fertilizer is the most appropriate to ensure crop yields sufficient to ensure local and global food security, while at the same time limiting environmental impact?
Answering this question remains a huge challenge, but the latest reliable data from FAO's database for statistics (FAO) can support deeper exploration. The new information tool is the result of the joint efforts of the Food and Agriculture Organization of the United Nations (FAO) and the International Fertilizer Association (IFA), together with top scientists and experts from the University of Maryland's Centre for Environmental Science, the Swedish University of Agricultural Sciences, the Centre for Agriculture and Environmental Risk Research at the Polytechnic University of Madrid, the Wageningen University and Research Centre, the University of Nebraska and the African Plant Nutrition Institute.
The collaboration has resulted in the development of new data on the nutrient gains and losses of farmland that can be used to measure the fertilizer inputs needed to support sustainable crop production and their possible environmental impacts.
At present, the Farmland Nutrient Profit and Loss has become the latest section in FAOSTAT, the world's largest food and agriculture database. This global public good platform provides FAO member countries and all stakeholders in the world's agrifood systems with access to harmonized data on yield, trade and consumption, while the latest section provides information on the flow of the three main plant macronutrients (nitrogen, phosphorus and potassium) necessary for crop growth.
As part of their international reporting obligations, countries provide FAO with basic crop and livestock production data. FAO combines the data with methodologies and models provided by the project's scientific partners to produce a set of common national reference data for the period 1961-2020, to be updated annually. Francesco Tubiello, FAO Senior Statistician, explained that FAOSTAT is a solid set of data tools based on basic national statistics to help address complex sustainable development challenges such as nutrient flows at national, regional and global levels.
Farmland nutrient gains and losses
Farmland nutrient profit and loss is an important indicator of nutrient flow, and agricultural inputs can be judged from the dimensions of the three main nutrients required for plant growth, including mineral, chemical and organic fertilizers.
It is calculated by adding the amount of mineral, chemical and manure applied to the soil of farmland, as well as the effect of biological nitrogen fixation (legumes are potent nitrogen fixers) and atmospheric deposition, minus the amount of nutrient outflow from crop harvest.
In principle, too many nutrients in the soil (recorded as surpluses) pose environmental risks, such as seepage into water sources or volatilization in the form of greenhouse gas emissions. On the other hand, nutrient deficiencies (recorded as deficiencies) often mean reduced crop yields or soil nutrient depletion.
This can also be converted to efficiency percentage, which is a measure of the efficiency of crop nutrient use (the ratio between nutrients consumed by crops and total nutrient inputs). However, the results of the data also reflect some potential problems that need to be handled with caution. For example, some seemingly alarming utilization rates may actually mean overconsumption of soil nutrients, often because fertilizer inputs are insufficient to support crop yield levels, thus leading to future yield shrinkage and unsustainability.
Key information
In 2020, 85 million tonnes of nitrogen (N), 7 million tonnes of phosphorus (P) and 12 million tonnes of potassium (K) were applied to farmland worldwide, a fourfold increase from 1961, with synthetic fertilizers accounting for an increasing proportion. The average application rates of nitrogen, phosphorus and potassium were 54 kg, 4 kg and 7 kg per hectare, respectively. Compared with the 60s of the 20th century, the application rate of nitrogen fertilizer increased by 3.4 times, the application rate of phosphate fertilizer remained unchanged, and the application rate of potassium fertilizer decreased by 36%. The utilization rate of all three fertilizers has increased in recent decades, averaging between 50% and 62% over the entire cycle recorded.
Nitrogen efficiency figures in Africa clearly show that crop production here is generally dependent on nutrients from natural soils.
China and India have the world's highest nitrogen surpluses, with utilization rates below the world average of 50%. In Brazil and the United States, the nitrogen surplus is much smaller, in part because the two countries grow soybeans on a large scale, and legumes supply natural biogenic nitrogen, so they have less fertilizer input.
Photographic data provides a new reference for assessing agricultural, environmental and sustainable development priorities. Fao
Some countries have surpluses in one key nutrient and severe shortages in another, including major agricultural countries such as Argentina, Nigeria and Ukraine. FAO statistician Nathan Wanner, a project member of the new database, explains that this may be because these countries have realigned their strategies based on the priorities of selected crops and fertilizers.
Sustainable agriculture goals
A better understanding of the nutrient gains and losses of farmland can help farmers and decision-makers better select and evaluate practices for more sustainable agriculture.
FAO is the custodian of SDG indicator 2.4.1, which monitors the proportion of agricultural areas engaged in productive and sustainable agriculture.
The newly introduced Farmland Nutrient P&L data offers a different approach that goes beyond the basic standard of using fertilizer application as a simplified benchmark. While policymakers are still divided on how to weigh fertilizer inputs, food production needs, and environmental protection, the new data provide a more balanced and complete way to understand how each element interacts during nutrient flow, so that effective strategies can be better found.
To promote and monitor sustainable agriculture using both basic statistics and complex data, FAO is actively taking action on a number of fronts, including the recent promotion of the PROSA (Monitoring Progress in Sustainable Agriculture) framework, hosting the Global Soil Cooperation and more recently developing a soil nutrient infographic.
