How Is Synthetic Nitrogen Fertilizer Made
- November 1, 2021
Many sources of fertilizer exist, both natural and industrially produced. For most modern agricultural practices, fertilization focuses on three main macro nutrients: Nitrogen (N), Phosphorus (P), and Potassium (K) with occasional addition of supplements like rock dust for micronutrients.In the later half of the 20th century, increased use of nitrogen fertilizers (800% increase between 1961 and 2019) have been a crucial component of the increased productivity of conventional food systems (more than 30% per capita) as part of the so-called "Green Revolution".The use of fertilizer has also led to a number of direct environmental consequences: agricultural runoff which leads to downstream effects like ocean dead zones and waterway contamination, soil microbiome degradation, and accumulation of toxins in ecosystems.Indirect environmental impacts include: the environmental impacts of fracking for natural gas used in the Haber process, the agricultural boom is partially responsible for the rapid growth in human population and large-scale industrial agricultural practices are associated with habitat destruction, pressure on biodiversity and agricultural soil loss.The Birkeland–Eyde process was one of the competing industrial processes in the beginning of nitrogen-based fertilizer production.The Haber process produces ammonia (NH 3 ) from methane (CH 4 ) gas and molecular nitrogen (N 2 ).A maize crop yielding 6–9 tonnes of grain per hectare (2.5 acres) requires 31–50 kilograms (68–110 lb) of phosphate fertilizer to be applied; soybean crops require about half, as 20–25 kg per hectare.One of the plants in the nutrient-poor soil has died.The nutrients required for healthy plant life are classified according to the elements, but the elements are not used as fertilizers."Multinutrient fertilizers" (or "complex fertilizers") provide two or more nutrients, for example N and P. Fertilizers are also sometimes classified as inorganic (the topic of most of this article) versus organic.Inorganic are sometimes called synthetic fertilizers since various chemical treatments are required for their manufacture.Single nutrient ("straight") fertilizers [ edit ].Urea is another popular source of nitrogen, having the advantage that it is solid and non-explosive, unlike ammonia and ammonium nitrate, respectively.The main straight phosphate fertilizers are the superphosphates.Major two-component fertilizers provide both nitrogen and phosphorus to the plants.The main NP fertilizers are monoammonium phosphate (MAP) and diammonium phosphate (DAP).NPK fertilizers are three-component fertilizers providing nitrogen, phosphorus, and potassium.Compound NPK fertilizers contain chemically bound ingredients, while blended NPK fertilizers are physical mixtures of single nutrient components.NPK rating is a rating system describing the amount of nitrogen, phosphorus, and potassium in a fertilizer.NPK ratings consist of three numbers separated by dashes (e.g., 10-10-10 or 16-4-8) describing the chemical content of fertilizers.Fertilizers do not actually contain P 2 O 5 or K 2 O, but the system is a conventional shorthand for the amount of the phosphorus (P) or potassium (K) in a fertilizer.Micronutrients [ edit ].Typical micronutrients are boron, zinc, molybdenum, iron, and manganese. These elements are provided as water-soluble salts.Production [ edit ].Nitrogen fertilizers [ edit ].Nitrogen fertilizers are made from ammonia (NH 3 ) produced by the Haber-Bosch process. Nitrates are also produced from ammonia by the Ostwald process.Phosphate fertilizers [ edit ].These minerals are converted into water-soluble phosphate salts by treatment with sulfuric (H 2 SO 4 ) or phosphoric acids (H 3 PO 4 ).Potassium fertilizers [ edit ].Chemical granulation process is based on chemical reactions between liquid raw materials (such as phosphoric acid, sulphuric acid, ammonia) and solid raw materials (such as potassium chloride, recycle material).Organic fertilizers [ edit ].On the other hand, marketed "organic fertilizers" may include, and promote, processed organics because the materials have consumer appeal.Some organic additives can have a reverse effect on nutrients – fresh sawdust can consume soil nutrients as it breaks down, and may lower soil pH – but these same organic texturizers (as well as compost, etc.).may increase the availability of nutrients through improved cation exchange, or through increased growth of microorganisms that in turn increase availability of certain plant nutrients.Application [ edit ].Fertilizers are commonly used for growing all crops, with application rates depending on the soil fertility, usually as measured by a soil test and according to the particular crop.Legumes, for example, fix nitrogen from the atmosphere and generally do not require nitrogen fertilizer.Liquid vs solid [ edit ].Fertilizers are applied to crops both as solids and as liquid.Urea [ edit ].During summer, urea is often spread just before or during rain to minimize losses from volatilization (a process wherein nitrogen is lost to the atmosphere as ammonia gas).Because of the high nitrogen concentration in urea, it is very important to achieve an even spread.Foliar application [ edit ].Various chemicals are used to enhance the efficiency of nitrogen-based fertilizers.The conversion of urea to ammonia catalyzed by enzymes called ureases. Fertilizer use (2018). Agricultural and chemical minerals are very important in industrial use of fertilizers, which is valued at approximately $200 billion. Nitrogen has a significant impact in the global mineral use, followed by potash and phosphate.Environmental effects [ edit ].Water [ edit ].Phosphorus and nitrogen fertilizers when commonly used have major environmental effects. If eutrophication can be reversed, it may take decades before the accumulated nitrates in groundwater can be broken down by natural processes.Nitrate pollution [ edit ]. High application rates of nitrogen-containing fertilizers combined with the high water solubility of nitrate leads to increased runoff into surface water as well as leaching into groundwater, thereby causing groundwater pollution. The excessive use of nitrogen-containing fertilizers (be they synthetic or natural) is particularly damaging, as much of the nitrogen that is not taken up by plants is transformed into nitrate which is easily leached. The nutrients, especially nitrates, in fertilizers can cause problems for natural habitats and for human health if they are washed off soil into watercourses or leached through soil into groundwater.Soil [ edit ].Accumulation of toxic elements [ edit ].Phosphate rocks contain high levels of fluoride.Radioactive elements [ edit ]. Uranium-238 concentrations can range from 7 to 100 pCi/g in phosphate rock and from 1 to 67 pCi/g in phosphate fertilizers.Highly pure fertilizers are widely available and perhaps best known as the highly water-soluble fertilizers containing blue dyes used around households, such as Miracle-Gro.Trace mineral depletion [ edit ]. Although improved crop yields resulting from NPK fertilizers are known to dilute the concentrations of other nutrients in plants, much of the measured decline can be attributed to the use of progressively higher-yielding crop varieties that produce foods with lower mineral concentrations than their less-productive ancestors.Changes in soil biology [ edit ].Energy consumption and sustainability [ edit ].In the US in 2004, 317 billion cubic feet of natural gas were consumed in the industrial production of ammonia, less than 1.5% of total U.S.
annual consumption of natural gas. A 2002 report suggested that the production of ammonia consumes about 5% of global natural gas consumption, which is somewhat under 2% of world energy production.The effects can be combined into an equivalent amount of carbon dioxide.The amount varies according to the efficiency of the process.Through the increasing use of nitrogen fertilizer, which was used at a rate of about 110 million tons (of N) per year in 2012, adding to the already existing amount of reactive nitrogen, nitrous oxide (N 2 O) has become the third most important greenhouse gas after carbon dioxide and methane.Two types of agricultural management practices include organic agriculture and conventional agriculture.Conventional agriculture uses all the components that organic agriculture does not use. .
Synthetic Fertilizer Ingredients
Synthetic fertilizer is shunned by organic gardeners and one reason is the fact that they are made from petroleum, or so it is claimed.Terms like oil-based fertilizer, petroleum fertilizer and petrochemical fertilizer have been used to describe synthetic fertilizers, as in this quote from a popular gardening blog, “Petrochemical fertilizers are another name for the synthetic products because they are produced using large quantities of petroleum.”.What is Petroleum?Natural gas is used to provide the methane and a heat source for the process.Sulfur Fertilizer.I guess you could say that sulfur is made from petroleum but we don’t use petroleum to make the sulfur.Sulfur is a waste product of other manufacturing processes, like making gasoline.Is Synthetic Fertilizer Petroleum Based?It can be argued that sulfur is petroleum based, but the sulfur produced from petroleum or a mine is identical.So why do terms like oil-based fertilizer and petroleum fertilizer exist?That is unfortunate, because there are very good arguments for using organic products instead of synthetic products, in some gardening situations. .
A Brief History of Our Deadly Addiction to Nitrogen Fertilizer
Nitrogen is extremely plentiful—it makes up nearly 80 percent of the air we breathe.And so agriculture’s millennia-old nitrogen-cycling problem was solved.Today’s industrial-scale farms would not be possible without it.Today’s fertilizer plants, reports Vaclav Smil in his seminal book on nitrogen fertilizer, Enriching the Earth, rely on a scaled-up, refined version of the same process developed by Haber.Today, the United States remains a massive nitrogen-fertilizer user; with just 5 percent of the world’s population, we consume about 12 percent of global nitrogen-fertilizer production.“If Big Ag becomes hooked on cheap fracked gas to meet its fertilizer needs,” I warned, “then the fossil fuel industry will have gained a powerful ally in its effort to steamroll regulation and fight back opposition to fracking projects.”.Another recent study by Cornell researchers found similar crop rotations also reduced nitrogen runoff. .
New research: synthetic nitrogen destroys soil carbon, undermines
For all of its ecological baggage, synthetic nitrogen does one good deed for the environment: it helps build carbon in soil.At a time of climate chaos and ever-growing global greenhouse gas emissions, anything that helps vast swaths of farmland sponge up carbon would be a stabilizing force.Well, that logic has come under fierce challenge from a team of University of Illinois researchers led by professors Richard Mulvaney, Saeed Khan, and Tim Ellsworth.In two recent papers (see here and here) the trio argues that the net effect of synthetic nitrogen use is to reduce soil’s organic matter content.A large amount of nitrogen then leaches away, fouling ground water in the form of nitrates, and entering the atmosphere as nitrous oxide (N2O), a greenhouse gas with some 300 times the heat-trapping power of carbon dioxide.In turn, with its ability to store organic nitrogen compromised, only one thing can help heavily fertilized farmland keep cranking out monster yields: more additions of synthetic N.Injured soil becomes prone to compaction, which makes it vulnerable to runoff and erosion and limits the growth of stabilizing plant roots.If the Illinois team is correct, synthetic nitrogen’s effect on carbon sequestration swings from being an important ecological advantage to perhaps its gravest liability.In an essay in the important 2002 anthology Fatal Harvest Reader, the California organic farmer Jason McKenney puts it like this:.Sir Albert’s denouncement sits in a dusty old tome that’s pretty obscure even within the organic-agriculture world; Jason McKenney is an organic farmer who operates near Berkeley–considered la-la land by mainstream soil scientists.By contrast, Mulvaney and his colleagues are living, credentialed scientists working at the premier research university in one of the nation’s most prodigious corn-producing–and nitrogen-consuming –states.To come to their conclusions, the researchers studied data from the Morrow plots on the University of Illinois’ Urbana-Champaign campus, which comprise the “the world’s oldest experimental site under continuous corn” cultivation.Mulvaney and his collaborators analyzed annual soil-test data in test plots that were planted with three crop rotations: continuous corn, corn-soy, and corn-oats-hay.The practice of year-after-year fertilization had pushed the Morrow plots onto the chemical treadmill: unable to efficiently store nitrogen, they became reliant on the next fix.“Such evidence is common in the scientific literature but has seldom been acknowledged, perhaps because N fertilizer practices have been predicated largely on short-term economic gain rather than long-term sustainability,” they write, citing some two dozen other studies which mirrored the patterns of the Morrow plots.The first, published as a letter to the editor (PDF) in the Journal of Environmental Quality, came from D. Keith Reid, a soil fertility specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs.Reid writes that the Mulvaney team’s conclusion about synthetic nitrogen and soil carbon is “sensational” and “would be incredibly important if it was true.”.In other words, modern farming — i.e., the kind practiced on nearly all farmland in the United States — destroys soil carbon.“We propose that the conclusion drawn by Mulvaney et al.
(2009), that inorganic N fertilizer causes a decline in soil organic N concentration, is false and not supported by the data from the Morrow Plots or from numerous studies worldwide,” they write.In the modern era of intensified agriculture, soils are generally managed as a commodity to maximize short-term economic gain.We also know that their analysis is consistent with the founding principles of organic agriculture: that properly applied manure and nitrogen-fixing cover crops, not synthetic nitrogen, are key to long-term soil health and fertility.But if Mulvaney and his team are correct, the future health of our farmland hinges on a dramatic shift away from reliance on synthetic nitrogen fertilizer. .
Greenhouse gas emissions from synthetic nitrogen manufacture and
This method has been applied in some previous studies to estimate synthetic N fertilizer-induced direct N 2 O emissions from Chinese croplands [10, 12, 21, 23].The direct N 2 O emission factor for Chinese uplands due to synthetic N fertilization was estimated to be 0.0105 kg N 2 O-N kg N−1 by Gao et al. , based on 261 N 2 O emission measurements in upland fields.The direct N 2 O emissions from synthetic N application for wheat and maize under 2016 cultivation were estimated to be 116 Gg N 2 O-N using the regional N 2 O emission factors of N applied .In this study, the total direct N 2 O emissions associated with synthetic N fertilization were estimated to be 105 Gg N 2 O year−1 for wheat and maize in China during the period of 2015–2017.Therefore, the adoption of crop-specific direct N 2 O emission factors at the regional level from Yue et al.
 would reduce uncertainty in the estimation of direct N 2 O emissions derived from synthetic N fertilization in Chinese uplands.There is still an issue of uncertainty for the estimation of GHG emissions from synthetic N manufacture in this study.During the 2015–2017 period, the average application rates of synthetic N for wheat and maize in upland fields of China were estimated to be 222 and 197 kg ha−1, respectively.The results of this study indicated that the area of synthetic N application rates higher than 200 kg ha−1 accounted for 70.0% in wheat and 32.4% in maize.For the purpose of mitigating emissions of GHG from Chinese agriculture without sacrificing crop yields, optimizing synthetic N application rate to a reasonable level in over-fertilized areas is an important and essential strategy. .
Synthetic nitrogen fertilizer: progress or doom?
“The world population is expected to reach 10 billion people in 2050, so we need to produce more food to feed everyone.”.The world population is expected to reach 10 billion in 2050 precisely because we keep producing more food.At the same time, more than 2 billion people are overweight.The Sustainable Development Goal of “zero hunger” is, in fact, not a challenge about food quantity, rather about food distribution.More food, more troubles?“Ecological agriculture is incompatible with capitalistic mass production.This process is technically referred to as soil degradation.“The depletion of the perpetual sources of that fertility” — Marx saw it right.As if that were not enough, the detrimental consequences of intensive farming do not stop at the soil, but propagate to water and atmosphere too.ii) Nitrous oxide emissions and global warming.iii) The carbon footprint of the Haber-Bosch process.i) Too rich water is dead water.Water systems are particularly susceptible to the chemical fluxes originating from polluted agricultural soil.Other than water ways, the surplus of nitrogen dropped on crop fields finds a second escape way directly in the atmosphere.Nitrous oxide in the atmosphere works as a booster too, but this time for global warming.That’s why nitrous oxide ranks only in third place after carbon dioxide and methane (i.e. “natural gas”) in terms of total contribution to the greenhouse effect.The environmental damage of synthetic nitrogen fertilizer does not only occur after it reaches the fields. .
'Grown using no synthetic nitrogen fertilizer...' sustainability claims
Connect Popcorn - initially launching direct to consumer at connectsnacks.com - features the prominent claim, ‘Grown using no synthetic nitrogen fertilizer,’ while Pivot Bio is also in talks with a range of CPG companies interested in making similar claims on pack, Pivot Bio co-founder and CEO Karsten Temme told FoodNavigator-USA.While some consumers are becoming more aware of the environmental footprint of food production and packaging, many are likely unaware that synthetic nitrogen fertilizer accounts for about 5% of the country’s greenhouse gas emissions, claimed Temme, who has raised a cool $600m+ since 2014 as investors have recognized the potential of its game-changing technology.While certain soil microbes (bacteria) have been breaking down atmospheric nitrogen and creating a useable form (ammonia) for plants to use as food for thousands of years by producing an enzyme that breaks down nitrogen’s chemical bonds, modern crops are typically grown with additional synthetic nitrogen fertilizer, said Temme.“And once we started using synthetic nitrogen fertilizer, it served as a kind of signal to the microbes to stop making that enzyme, so we’ve become more and more dependent on synthetic nitrogen fertilizer..By using Pivot Bio’s microbes, which are supplied to farmers as a liquid, farmers can also work more efficiently, he said. .
The downside of nitrogen fertilizer
An estimated 1/3 of global food production is made possible by its use, with 100 million tons applied to Earth’s surface annually.When aquatic plants die, their decomposition strips oxygen from the water, causing fish and shellfish kills.At the mouth of the Mississippi River, in the Gulf of Mexico, agricultural pollution has resulted in a dead zone the size of New Jersey.Ammonia is volatized from nitrogen fertilizer and it forms fine particles in the atmosphere that are hazardous to human health. .