A '''fertilizer''' or '''fertiliser''' is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply [[plant nutrition|plant nutrients]]. Fertilizers may be distinct from [[Liming (soil)|liming materials]] or other non-nutrient [[soil amendments]]. Many sources of fertilizer exist, both natural and [[Agrochemical|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 flour]] for micronutrients. Farmers apply these fertilizers in a variety of ways: through dry or pelletized or liquid application processes, using large agricultural equipment, or hand-tool methods.
Historically, fertilization came from natural or organic sources: [[compost]], [[Manure|animal manure]], [[Human waste|human manure]], harvested minerals, [[crop rotation]]s, and byproducts of human-nature industries (e.g. [[Fish meal|fish processing waste]], or [[Blood meal|bloodmeal]] from [[animal slaughter]]). However, starting in the 19th century, after innovations in [[plant nutrition]], an [[Industrial agriculture|agricultural industry]] developed around synthetically created [[Agrochemical|agrochemical fertilizers]]. This transition was important in transforming the [[Food system|global food system]], allowing for larger-scale [[Intensive farming|industrial agriculture]] with large crop yields.
[[Nitrogen fixation|Nitrogen-fixing]] chemical processes, such as the [[Haber process]] invented at the beginning of the 20th century, and amplified by production capacity created during World War II, led to a boom in using nitrogen fertilizers. In the latter half of the 20th century, increased use of nitrogen fertilizers (800% increase between 1961 and 2019) has 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]]".
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
人工肥料および工業的に施用される肥料の使用は、栄養素の流出による[[:en:water pollution|水質汚染]]や[[:en:eutrophication|富栄養化]]、肥料の生産および採掘による[[:en:Carbon emissions|炭素]]その他の排出、そして[[:en:Soil contamination|土壌の汚染]]などの環境問題を引き起こしている。肥料や[[:en:pesticide|農薬]]の使用による悪影響や[[:en:Environmental impact of agriculture|工業的農業]]による[[:en:Environmental impact of agriculture|環境破壊]]を減らすために、様々な[[:en:sustainable agriculture|持続可能な農業]]慣行が実施され得る。
The use of artificial and industrially applied fertilizers has caused environmental consequences such as [[water pollution]] and [[eutrophication]] due to nutritional runoff; [[Carbon emissions|carbon]] and other emissions from fertilizer production and mining; and [[Soil contamination|contamination and pollution of soil]]. Various [[sustainable agriculture]] practices can be implemented to reduce the adverse environmental effects of fertilizer and [[pesticide]] use and [[Environmental impact of agriculture|environmental damage]] caused by [[industrial agriculture]].
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
{{TOC limit}}
{{TOC limit}}
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
== 歴史{{Anchor|History}} ==
==History==
{{Main/ja|:en:History of fertilizer}}
{{Main|History of fertilizer}}
[[File:Total fertilizer production by nutrient, OWID.svg|thumb|upright=1.6|種類別肥料総生産量。]]
[[File:Total fertilizer production by nutrient, OWID.svg|thumb|upright=1.6|Total fertilizer production by type.]]
[[File:World population supported by synthetic nitrogen fertilizers, OWID.svg|thumb|upright=1.6|合成窒素肥料の有無による世界の人口扶養数。]]
[[File:World population supported by synthetic nitrogen fertilizers, OWID.svg|thumb|upright=1.6|World population supported with and without synthetic nitrogen fertilizers.]]
[[File:Instalaciones MIRAT S.A. Salamanca.JPG|thumb|Founded in 1812, [[Mirat]], producer of [[manure]]s and fertilizers, is claimed to be the oldest industrial business in [[Salamanca]] (Spain).]]
[[File:Cropland Nitrogen Budget By Component And Region.svg|thumb|作物の窒素収支の構成要素別・地域別。大部分は肥料に由来する。]]
[[File:Cropland Nitrogen Budget By Component And Region.svg|thumb|Cropland nitrogen budget by component and region, a large proportion comes from fertilizers.]]
[[:en:soil fertility|土壌の肥沃度]]管理は、農業が始まって以来、農民の関心事であった。中東、中国、メソアメリカ、中央アンデスの文化はすべて、農業の初期採用者であった。これにより、これらの文化の人口が急速に増加し、隣接する狩猟採集民グループへの文化の輸出が可能になったと考えられている(P Bellwood - 2023)。エジプト人、ローマ人、バビロニア人、初期のドイツ人は皆、農地の生産性を高めるために鉱物や肥料を使用していたと記録されている。植物栄養に関する科学的研究は、ドイツの化学者[[:en:Justus von Liebig|ユストゥス・フォン・リービッヒ]]の業績よりもずっと前に始まっていたが、彼の名前は「肥料産業の父」として最もよく言及されている。[[:en:Nicolas Théodore de Saussure|ニコラ・テオドール・ド・ソシュール]]と当時の科学者たちは、フォン・リービッヒの単純化をすぐに否定した。フォン・リービッヒが影響を受けた著名な科学者には、[[:en:Carl Ludwig Sprenger|カール・ルートヴィヒ・シュプレンガー]]と[[:en:Hermann Hellriegel|ヘルマン・ヘルリーゲル]]がいる。この分野では、経済学と研究の混交が部分的に拍車をかけた「知識の浸食」が起こった。イギリスの[[:en:entrepreneur|起業家]]である[[:en:John Bennet Lawes|ジョン・ベネット・ローズ]]は、1837年に鉢植え植物に対する様々な肥料の効果を実験し始め、1、2年後にはその実験を畑の作物にまで拡大した。その直接の結果として、1842年にリン酸塩を硫酸で処理して形成される肥料の特許を取得し、人工肥料産業を最初に創設した人物となった。翌年、彼は[[:en:Joseph Henry Gilbert|ジョセフ・ヘンリー・ギルバート]]の協力を得て、[[:en:Rothamsted Research|ローザムステッド研究センター]]で作物実験を行った。
Management of [[soil fertility]] has preoccupied farmers since the beginning of agriculture. Middle Eastern, Chinese, Mesoamerican, and Cultures of the Central Andes were all early adopters of agriculture. This is thought to have led to their cultures growing faster in population which allowed an exportation of culture to neighboring hunter-gatherer groups. Fertilizer use along with agriculture allowed some of these early societies a critical advantage over their neighbors, leading them to become dominant cultures in their respective regions (P Bellwood - 2023''''''. Egyptians, Romans, Babylonians, and early Germans are all recorded as using minerals or manure to enhance the productivity of their farms. The scientific research of plant nutrition started well before the work of German chemist [[Justus von Liebig]] although his name is most mentioned as the "father of the fertilizer industry". [[Nicolas Théodore de Saussure]] and scientific colleagues at the time were quick to disprove the simplifications of von Liebig. Prominent scientists whom von Liebig drew were [[Carl Ludwig Sprenger]] and [[Hermann Hellriegel]]. In this field, a 'knowledge erosion' took place, partly driven by an intermingling of economics and research. [[John Bennet Lawes]], an English [[entrepreneur]], began experimenting on the effects of various manures on plants growing in pots in 1837, and a year or two later the experiments were extended to crops in the field. One immediate consequence was that in 1842 he patented a manure formed by treating phosphates with sulfuric acid, and thus was the first to create the artificial manure industry. In the succeeding year, he enlisted the services of [[Joseph Henry Gilbert]]; together they performed crop experiments at the [[Rothamsted Research|Institute of Arable Crops Research]].
The [[Birkeland–Eyde process]] was one of the competing industrial processes at the beginning of nitrogen-based fertilizer production. This process was used to fix atmospheric [[nitrogen]] (N<sub>2</sub>) into [[nitric acid]] (HNO<sub>3</sub>), one of several chemical processes called [[nitrogen fixation]]. The resultant nitric acid was then used as a source of [[nitrate]] (NO<sub>3</sub><sup>−</sup>). A factory based on the process was built in [[Rjukan]] and [[Notodden]] in Norway and large [[hydroelectric power]] facilities were built.
The 1910s and 1920s witnessed the rise of the [[Haber process]] and the [[Ostwald process]]. The Haber process produces ammonia (NH<sub>3</sub>) from [[methane]] (CH<sub>4</sub>) ([[natural gas]]) gas and molecular nitrogen (N<sub>2</sub>) from the air. The ammonia from the Haber process is then partially converted into [[nitric acid]] (HNO<sub>3</sub>) in the [[Ostwald process]]. It is estimated that a third of annual global food production uses ammonia from the Haber–Bosch process and that this supports nearly half the world's population. After World War II, nitrogen production plants that had ramped up for wartime bomb manufacturing were pivoted towards agricultural uses. The use of synthetic nitrogen fertilizers has increased steadily over the last 50 years, rising almost 20-fold to the current rate of 100 million [[tonnes]] of nitrogen per year.
The development of synthetic nitrogen fertilizers has significantly supported global population growth. It has been estimated that almost half the people on the Earth are currently fed due to synthetic nitrogen fertilizer use. The use of phosphate fertilizers has also increased from 9 million tonnes per year in 1960 to 40 million tonnes per year in 2000.
Agricultural use of inorganic fertilizers in 2021 was 195 million tonnes of nutrients, of which 56% was nitrogen. Asia represented 53% of the world's total agricultural use of inorganic fertilizers in 2021, followed by the Americas (29%), Europe (12%), Africa (4%) and Oceania (2%). This ranking of the regions is the same for all nutrients. The main users of inorganic fertilizers are, in descending order, China, India, Brazil, and the United States of America (see Table 15), with China the largest user of each nutrient.
A maize crop yielding 6–9 tonnes of grain per [[hectare]] ({{cvt|1|ha|acre |1|disp=out}}) requires {{convert|31|–|50|kg}} of [[phosphate]] fertilizer to be applied; soybean crops require about half, 20–25 kg per hectare.
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
== メカニズム{{Anchor|Mechanism}} ==
==Mechanism==
[[File:Reuse of urine demonstration - fertilised and not fertilised tomato plant experiment (3617543234).jpg|thumb|upright=1.4|養分不足の砂/粘土質土壌で硝酸肥料を与えたトマト植物と与えていないトマト植物6株。養分不足の土壌の植物の1つは枯れている。]]
[[File:Reuse of urine demonstration - fertilised and not fertilised tomato plant experiment (3617543234).jpg|thumb|upright=1.4|Six tomato plants grown with and without nitrate fertilizer on nutrient-poor sand/clay soil. One of the plants in the nutrient-poor soil has died.]]
[[File:Inorganic Fertilizer Use By Region.svg|thumb|upright=1.5|地域別無機肥料使用量]]
[[File:Inorganic Fertilizer Use By Region.svg|thumb|upright=1.5|Inorganic fertilizer use by region]]
Fertilizers enhance the growth of plants. This goal is met in two ways, the traditional one being additives that provide nutrients. The second mode by which some fertilizers act is to enhance the effectiveness of the soil by modifying its water retention and aeration. This article, like many on fertilizers, emphasizes the nutritional aspect.
The nutrients required for healthy plant life are classified according to the elements, but the elements are not used as fertilizers. Instead, [[chemical compound|compounds]] containing these elements are the basis of fertilizers. The macro-nutrients are consumed in larger quantities and are present in plant tissue in quantities from 0.15% to 6.0% on a [[dry matter]] (DM) (0% moisture) basis. Plants are made up of four main elements: hydrogen, oxygen, carbon, and nitrogen. Carbon, hydrogen, and oxygen are widely available respectively in [[carbon dioxide]] and in water. Although nitrogen makes up most of the [[atmosphere]], it is in a form that is unavailable to plants. Nitrogen is the most important fertilizer since nitrogen is present in [[protein]]s ([[amide bond]]s between [[amino-acid|amino acid]]s), [[DNA]] ([[purine|puric]] and [[pyrimidine|pyrimidic]] bases), and other components (e.g., [[porphyrin|tetrapyrrolic]] [[heme]] in [[chlorophyll]]). To be nutritious to plants, nitrogen must be made available in a "fixed" form. Only some bacteria and their host plants (notably [[legume]]s) can fix atmospheric nitrogen ({{chem2|N2}}) by converting it to [[ammonia]] ({{chem2|NH3}}). [[Phosphate]] ({{chem2|PO4(3-)}}) is required for the production of [[Deoxyribonucleic acid|DNA]] ([[genetic code]]) and [[Adenosine triphosphate|ATP]], the main energy carrier in [[Cell (biology)|cells]], as well as certain [[lipid]]s ([[phospholipid]]s, the main components of the [[liposome|lipidic double layer]] of the [[cell membrane]]s).
The first is the [[hydrolysis]] (reaction with water) of [[urea]] ({{chem2|CO(NH2)2}}). Many [[soil]] [[bacteria]] possess the enzyme [[urease]], which [[catalysis|catalyzes]] the conversion of urea to [[ammonium]] ion ({{chem2|NH4+}}) and [[bicarbonate]] [[ion]] ({{chem2|HCO3-}}).
[[Ammonia-oxidizing bacteria]] (AOB), such as species of ''[[Nitrosomonas]]'', [[Redox|oxidize]] ammonia ({{chem2|NH3}}) to [[nitrite]] ({{chem2|NO2-}}), a process termed [[nitrification]]. [[Nitrite-oxidizing bacteria]], especially ''[[Nitrobacter]]'', oxidize [[nitrite]] ({{chem2|NO2-}}) to [[nitrate]] ({{chem2|NO3-}}), which is extremely [[solubility|soluble]] and mobile and is a major cause of [[eutrophication]] and [[algal bloom]].
Fertilizers are classified in several ways. They are classified according to whether they provide a single nutrient (e.g., K, P, or N), in which case they are classified as "straight 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 fertilizers exclude carbon-containing materials except [[ureas]]. Organic fertilizers are usually (recycled) plant- or animal-derived matter. Inorganic are sometimes called synthetic fertilizers since various chemical treatments are required for their manufacture.
* [[Urea]] (CO(NH<sub>2</sub>)<sub>2</sub>), with 45-46% nitrogen, another popular source of nitrogen, having the advantage that it is solid and non-explosive, unlike ammonia and ammonium nitrate.
* [[Calcium ammonium nitrate]] Is a blend of 20-30% [[limestone]] CaCO<sub>3</sub> or [[Dolomite (mineral)|dolomite]] (Ca,Mg)CO<sub>3</sub> and 70-80% [[ammonium nitrate]] with 24-28 % nitrogen.
* "Single superphosphate" (SSP) consisting of 14–18% P<sub>2</sub>O<sub>5</sub>, again in the form of Ca(H<sub>2</sub>PO<sub>4</sub>)<sub>2</sub>, but also [[phosphogypsum]] ({{chem2|Ca[[SO4]] * 2 H2O}}).
A mixture of single superphosphate and triple superphosphate is called double superphosphate. More than 90% of a typical superphosphate fertilizer is water-soluble.
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
主なカリウムベースの単肥は、[[muriate of potash/ja|塩化カリウム]](MOP、95〜99% KCl)である。通常、0-0-60または0-0-62肥料として利用可能である。
The main potassium-based straight fertilizer is [[muriate of potash]] (MOP, 95–99% KCl). It is typically available as 0-0-60 or 0-0-62 fertilizer.
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
=== 多量養分肥料 ===
===Multinutrient fertilizers===
これらの肥料は一般的である。これらは2つ以上の養分成分から構成される。
These fertilizers are common. They consist of two or more nutrient components.
*[[diammonium phosphate]] (DAP). (NH<sub>4</sub>)<sub>2</sub>HPO<sub>4</sub>. With 18% nitrogen and 46% P<sub>2</sub>O<sub>5</sub>
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
MAPおよびDAP肥料の約85%は水溶性である。
About 85% of MAP and DAP fertilizers are soluble in water.
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
; NPK肥料
;NPK fertilizers
{{Main/ja|:en:Labeling of fertilizer}}
{{Main|Labeling of fertilizer}}
{{Imageright|
{{multiple image
{{multiple image
| width = 200
| width = 200
| footer =
| footer =
| image1 = Compound fertiliser.jpg
| image1 = Compound fertiliser.jpg
| alt1 = Compound fertiliser
| alt1 = 複合肥料
| caption1 = Compound fertilizer
| caption1 = 化成肥料
| image2 = Bulk-blend fertiliser.jpg
| image2 = Bulk-blend fertiliser.jpg
| alt2 = Bulk-blend fertiliser
| alt2 = Bulk-blend fertiliser
| caption2 = Bulk-blend fertilizer
| caption2 = バルクブレンド肥料
}}
}}}}
NPK fertilizers are three-component fertilizers providing nitrogen, phosphorus, and potassium. There exist two types of NPK fertilizers: compound and blends. 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. The first number represents the percentage of nitrogen in the product; the second number, P<sub>2</sub>O<sub>5</sub>; the third, K<sub>2</sub>O. Fertilizers do not actually contain P<sub>2</sub>O<sub>5</sub> or K<sub>2</sub>O, but the system is a conventional shorthand for the amount of the phosphorus (P) or potassium (K) in a fertilizer. A {{convert|50|lb|adj=on}} bag of fertilizer labeled 16-4-8 contains {{cvt|8|lb}} of nitrogen (16% of the 50 pounds), an amount of phosphorus equivalent to that in 2 pounds of P<sub>2</sub>O<sub>5</sub> (4% of 50 pounds), and 4 pounds of K<sub>2</sub>O (8% of 50 pounds). Most fertilizers are labeled according to this N-P-K convention, although Australian convention, following an N-P-K-S system, adds a fourth number for sulfur, and uses elemental values for all values including P and K.
[[Micronutrients]] are consumed in smaller quantities and are present in plant tissue on the order of [[Parts-per notation|parts-per-million]] (ppm), ranging from 0.15 to 400 ppm or less than 0.04% dry matter. These elements are often required for enzymes essential to the plant's metabolism. Because these elements enable catalysts (enzymes), their impact far exceeds their weight%age. Typical micronutrients are [[boron]], [[zinc]], [[molybdenum]], [[iron]], and [[manganese]]. These elements are provided as water-soluble salts. Iron presents special problems because it converts to insoluble (bio-unavailable) compounds at moderate soil pH and phosphate concentrations. For this reason, iron is often administered as a [[Chelation|chelate complex]], e.g., the [[Ethylenediaminetetraacetic acid|EDTA]] or [[EDDHA]] derivatives. The micronutrient needs depend on the plant and the environment. For example, [[sugar beet]]s appear to require [[boron]], and [[legume]]s require [[cobalt]],
The production of synthetic, or inorganic, fertilizers require prepared chemicals, whereas organic fertilizers are derived from the organic processes of plants and animals in [[biological process]]es using biochemicals.
[[File:Nitrogen fertilizer consumption, OWID.svg|thumb|left|Total nitrogenous fertilizer consumption per region, measured in tonnes of total nutrient per year.]]
Nitrogen fertilizers are made from [[ammonia]] (NH<sub>3</sub>) [[ammonia production|produced]] by the [[Haber process|Haber–Bosch process]]. In this energy-intensive process, [[natural gas]] (CH<sub>4</sub>) [[Hydrogen production|usually]] [[Steam reforming|supplies the hydrogen]], and the nitrogen (N<sub>2</sub>) is [[Nitrogen#Production|derived from the air]]. This ammonia is used as a [[feedstock]] for all other nitrogen fertilizers, such as [[ammonium nitrate|anhydrous ammonium nitrate]] (NH<sub>4</sub>NO<sub>3</sub>) and [[urea]] (CO(NH<sub>2</sub>)<sub>2</sub>).
Deposits of [[sodium nitrate]] (NaNO<sub>3</sub>) ([[Chilean saltpeter]]) are also found in the [[Atacama Desert]] in [[Chile]] and was one of the original (1830) nitrogen-rich fertilizers used. It is still mined for fertilizer. Nitrates are also produced from ammonia by the [[Ostwald Process|Ostwald process]].
Phosphate fertilizers are obtained by extraction from [[phosphate rock]], which contains two principal phosphorus-containing minerals, [[fluorapatite]] Ca<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>F (CFA) and [[hydroxyapatite]] Ca<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>OH. Billions of kg of phosphate rock are mined annually, but the size and quality of the remaining ore is decreasing. These minerals are converted into water-soluble phosphate salts by treatment with [[acid]]s. The large production of [[sulfuric acid]] is primarily motivated by this application. In the [[nitrophosphate process]] or Odda process (invented in 1927), phosphate rock with up to a 20% phosphorus (P) content is dissolved with [[nitric acid]] (HNO<sub>3</sub>) to produce a mixture of phosphoric acid (H<sub>3</sub>PO<sub>4</sub>) and [[calcium nitrate]] (Ca(NO<sub>3</sub>)<sub>2</sub>). This mixture can be combined with a potassium fertilizer to produce a ''compound fertilizer'' with the three macronutrients N, P and K in easily dissolved form.
[[Potash]] is a mixture of potassium minerals used to make potassium (chemical symbol: K) fertilizers. Potash is soluble in water, so the main effort in producing this nutrient from the ore involves some purification steps, e.g., to remove [[sodium chloride]] (NaCl) (common [[salt]]). Sometimes potash is referred to as K<sub>2</sub>O, as a matter of convenience to those describing the potassium content. In fact, potash fertilizers are usually [[potassium chloride]], [[potassium sulfate]], [[potassium carbonate]], or [[potassium nitrate]].
# The wet process is based on chemical reactions between liquid raw materials [[phosphoric acid]], [[sulfuric acid]], [[ammonia]]) and solid raw materials (such as [[potassium chloride]]).
"[[Organic fertilizer]]s" can describe those fertilizers with a biologic origin—derived from living or formerly living materials. Organic fertilizers can also describe commercially available and frequently packaged products that strive to follow the expectations and restrictions adopted by "[[organic agriculture]]" and "[[environmentally friendly]]" gardening – related systems of food and plant production that significantly limit or strictly avoid the use of synthetic fertilizers and pesticides. The "organic fertilizer" ''products'' typically contain both some organic materials as well as acceptable additives such as nutritive rock powders, ground seashells (crab, oyster, etc.), other prepared products such as seed meal or kelp, and cultivated microorganisms and derivatives.
Fertilizers of an organic origin (the first definition) include [[manure|animal wastes]], plant wastes from agriculture, [[Seaweed fertilizer|seaweed]], [[compost]], and treated [[sewage sludge]] ([[biosolid]]s). Beyond manures, animal sources can include products from the slaughter of animals – [[bloodmeal]], [[bone meal]], [[feather meal]], hides, hoofs, and horns all are typical components. Organically derived materials available to industry such as sewage sludge may not be acceptable components of organic farming and gardening, because of factors ranging from residual contaminants to public perception. On the other hand, marketed "organic fertilizers" may include, and promote, processed organics ''because'' the materials have consumer appeal. No matter the definition nor composition, most of these products contain less-concentrated nutrients, and the nutrients are not as easily quantified. They can offer soil-building advantages as well as be appealing to those who are trying to farm / garden more "naturally".
In terms of volume, [[peat]] is the most widely used packaged organic soil amendment. It is an immature form of coal and improves the soil by aeration and absorbing water but confers no nutritional value to the plants. It is therefore not a fertilizer as defined in the beginning of the article, but rather an amendment. [[Coir]], (derived from coconut husks), bark, and sawdust when added to soil all act similarly (but not identically) to peat and are also considered organic soil amendments – or texturizers – because of their limited nutritive inputs. 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. Organic fertilizers such as composts and manures may be distributed locally without going into industry production, making actual consumption more difficult to quantify.
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
== 肥料消費量{{Anchor|Fertilizer consumption}} ==
==Fertilizer consumption==
[[File:FERTILIZER USE (2018).svg|right|thumb|upright=1.5|肥料使用量(2018年)。FAO世界食料農業統計年鑑2020より]]
[[File:FERTILIZER USE (2018).svg|right|thumb|upright=1.5|Fertilizer use (2018). From FAO's World Food and Agriculture – Statistical Yearbook 2020]]
[[File:Fertilizer consumption in Europe.png|right|thumb|upright=1.5|この図は、世界銀行が2012年に発表したデータから、西ヨーロッパおよび中央ヨーロッパ諸国の[[https://docs.google.com/spreadsheets/d/1HzGlIAHphywl3AO2-S_aXDAS0VLL4IU6V19fVptSnjs/pubchart?oid=1097435817&format=interactive 肥料消費量]]統計を示している。]]
[[File:Fertilizer consumption in Europe.png|right|thumb|upright=1.5|The diagram displays the statistics of [https://docs.google.com/spreadsheets/d/1HzGlIAHphywl3AO2-S_aXDAS0VLL4IU6V19fVptSnjs/pubchart?oid=1097435817&format=interactive fertilizer consumption] in western and central European counties from data published by The World Bank for 2012.]]
! N use for<br />feed and<br />pasture<br />(Mt pa)
! 飼料・牧草用<br />窒素使用量<br />(百万トン/年)
|-
|-
| China
| [[:en:China|中国]]
| 18.7
| 18.7
| 3.0
| 3.0
|-
|-
| India
| [[:en:India|インド]]
| 11.9
| 11.9
| n/a
| n/a
|-
|-
| U.S.
| [[:en:United States|米国]]
| 9.1
| 9.1
| 4.7
| 4.7
|-
|-
| France
| [[:en:France|フランス]]
| 2.5
| 2.5
| 1.3
| 1.3
|-
|-
| Germany
| [[:en:Germany|ドイツ]]
| 2.0
| 2.0
| 1.2
| 1.2
|-
|-
| [[Brazil]]
| [[:en:Brazil|ブラジル]]
| 1.7
| 1.7
| 0.7
| 0.7
|-
|-
| Canada
| [[:en:Canada|カナダ]]
| 1.6
| 1.6
| 0.9
| 0.9
|-
|-
| [[Turkey]]
| [[:en:Turkey|トルコ]]
| 1.5
| 1.5
| 0.3
| 0.3
|-
|-
| UK
| [[:en:United Kingdom|英国]]
| 1.3
| 1.3
| 0.9
| 0.9
|-
|-
| [[Mexico]]
| [[:en:Mexico|メキシコ]]
| 1.3
| 1.3
| 0.3
| 0.3
|-
|-
| Spain
| [[:en:Spain|スペイン]]
| 1.2
| 1.2
| 0.5
| 0.5
|-
|-
| [[Argentina]]
| [[:en:Argentina|アルゼンチン]]
| 0.4
| 0.4
| 0.1
| 0.1
|}
|}
China has become the largest producer and consumer of nitrogen fertilizers while Africa has little reliance on nitrogen fertilizers. 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. The production of nitrogen has drastically increased since the 1960s. Phosphate and potash have increased in price since the 1960s, which is larger than the consumer price index. Potash is produced in Canada, Russia and Belarus, together making up over half of the world production. Potash production in Canada rose in 2017 and 2018 by 18.6%. Conservative estimates report 30 to 50% of crop yields are attributed to natural or synthetic commercial fertilizers. Fertilizer consumption has surpassed the amount of farmland in the United States.
2012年の[[:en:arable land|耕地]]1ヘクタールあたりの肥料消費量データは[[:en:The World Bank|世界銀行]]によって公表されている。下の図は、欧州連合(EU)諸国による肥料消費量を1ヘクタールあたりキログラム(1エーカーあたりポンド)で示している。EU全体の肥料消費量は、1億500万ヘクタールの耕地面積に対し1590万トン(別の推定によると1億700万ヘクタールの耕地面積)である。この数値は、EU諸国で平均して耕地1ヘクタールあたり151kgの肥料が消費されていることに相当する。
Data on the fertilizer consumption per hectare [[arable land]] in 2012 are published by [[The World Bank]]. The diagram below shows fertilizer consumption by the European Union (EU) countries as kilograms per hectare (pounds per acre). The total consumption of fertilizer in the EU is 15.9 million tons for 105 million hectare arable land area (or 107 million hectare arable land according to another estimate). This figure equates to 151 kg of fertilizers consumed per ha arable land on average by the EU countries.
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.
Fertilizers are applied to crops both as solids and as liquid. About 90% of fertilizers are applied as solids. The most widely used solid inorganic fertilizers are [[urea]], diammonium phosphate and potassium chloride. Solid fertilizer is typically granulated or powdered. Often solids are available as [[prill]]s, a solid globule. Liquid fertilizers comprise anhydrous ammonia, aqueous solutions of ammonia, aqueous solutions of ammonium nitrate or urea. These concentrated products may be diluted with water to form a concentrated liquid fertilizer (e.g., [[UAN]]). Advantages of liquid fertilizer are its more rapid effect and easier coverage. The addition of fertilizer to irrigation water is called "[[fertigation]]".
Urea is highly soluble in water and is therefore also very suitable for use in fertilizer solutions (in combination with ammonium nitrate: UAN), e.g., in 'foliar feed' fertilizers. For fertilizer use, granules are preferred over prills because of their narrower particle size distribution, which is an advantage for mechanical application.
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
尿素は通常、40〜300kg/ha(35〜270lbs/エーカー)の割合で散布されるが、その割合は様々である。少量施用の場合、[[:en:leaching|浸出]]による損失が少ない。夏期には、[[:en:ammonia volatilization from urea|揮発]](窒素がアンモニアガスとして大気中に失われるプロセス)による損失を最小限に抑えるため、尿素は雨の直前または降雨中に散布されることが多い。
Urea is usually spread at rates of between 40 and 300 kg/ha (35 to 270 lbs/acre) but rates vary. Smaller applications incur lower losses due to leaching. During summer, urea is often spread just before or during rain to minimize losses from [[ammonia volatilization from urea|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. Drilling must not occur on contact with or close to seed, due to the risk of germination damage. Urea dissolves in water for application as a spray or through irrigation systems.
In grain and cotton crops, urea is often applied at the time of the last cultivation before planting. In high rainfall areas and on sandy soils (where nitrogen can be lost through leaching) and where good in-season rainfall is expected, urea can be side- or top-dressed during the growing season. Top-dressing is also popular on pasture and forage crops. In cultivating sugarcane, urea is side dressed after planting and applied to each [[ratooning|ratoon]] crop.
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
尿素は空気中の水分を吸収するため、密閉容器に保管されることが多い。
Because it absorbs moisture from the atmosphere, urea is often stored in closed containers.
[[Foliar feeding|Foliar fertilizers]] are applied directly to leaves. This method is almost invariably used to apply water-soluble straight nitrogen fertilizers and used especially for high-value crops such as fruits. Urea is the most common foliar fertilizer.
Various chemicals are used to enhance the efficiency of nitrogen-based fertilizers. In this way farmers can limit the [[nitrogen pollution|polluting effects of nitrogen run-off]]. [[Nitrification]] inhibitors (also known as nitrogen stabilizers) suppress the conversion of ammonia into [[nitrate]], an anion that is more prone to leaching. 1-Carbamoyl-3-methylpyrazole (CMP), [[dicyandiamide]], [[nitrapyrin]] (2-chloro-6-trichloromethylpyridine) and 3,4-dimethylpyrazole phosphate (DMPP) are popular. [[Urease inhibitor]]s are used to slow the hydrolytic conversion of urea into ammonia, which is prone to evaporation as well as nitrification. The conversion of urea to ammonia catalyzed by enzymes called [[urease]]s. A popular inhibitor of ureases is ''N''-(''n''-butyl)thiophosphoric triamide ([[NBPT]]).
Careful use of fertilization technologies is important because excess nutrients can be detrimental. [[Fertilizer burn]] can occur when too much fertilizer is applied, resulting in damage or even death of the plant. Fertilizers vary in their tendency to burn roughly in accordance with their [[salt index]].
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
== 環境への影響{{Anchor|Environmental effects}} ==
==Environmental effects==
[[File:Runoff of soil & fertilizer.jpg|thumb|[[:en:Surface runoff|降雨]]時の[[soil|土壌]]と肥料の[[:en:Surface runoff|流出]]]]
[[File:Runoff of soil & fertilizer.jpg|thumb|[[Surface runoff|Runoff]] of [[soil]] and fertilizer during a rain storm]]{{See also|Environmental impact of agriculture|Human impact on the nitrogen cycle|Nitrogen fertilizer#Problems with inorganic fertilizer|Nitrogen Cycle}}Synthetic fertilizer used in agriculture has [[Environmental impact of agriculture|wide-reaching environmental consequences]].
{{See also/ja|:en:Environmental impact of agriculture|:en:Human impact on the nitrogen cycle|Nitrogen fertilizer#Problems with inorganic fertilizer|:en:Nitrogen Cycle}}
</div>
農業で使用される''合成肥料''は、[[:en:Environmental impact of agriculture|広範囲にわたる環境への影響]]を及ぼす。
<div lang="en" dir="ltr" class="mw-content-ltr">
[[:en:Intergovernmental Panel on Climate Change|気候変動に関する政府間パネル(IPCC)]]の[[:en:Special Report on Climate Change and Land|気候変動と土地に関する特別報告書]]によると、これらの肥料の生産と関連する[[:en:land use|土地利用]]慣行は、[[:en:global warming|地球温暖化]]の推進要因である。肥料の使用はまた、多くの直接的な環境への影響を引き起こしている。[[:en:agricultural runoff|農業排水]]による[[:en:Dead zone (ecology)|海洋のデッドゾーン]]や水路汚染といった下流への影響、[[:en:soil microbiome|土壌微生物叢]]の劣化、生態系における毒素の蓄積などである。間接的な環境への影響としては、[[:en:Haber process|ハーバー・ボッシュ法]]で使用される[[natural gas/ja|天然ガス]]の[[:en:Hydraulic fracturing|水圧破砕による環境への影響]]、農業のブームが[[:en:Human population growth|人口の急速な増加]]の一因となっていること、大規模な工業的農業慣行が[[:en:habitat destruction|生息地の破壊]]、[[:en:Biodiversity loss|生物多様性への圧力]]、農業[[:en:soil loss|土壌損失]]と関連していることが挙げられる。
According to the [[Intergovernmental Panel on Climate Change|Intergovernmental Panel on Climate Change (IPCC)]] [[Special Report on Climate Change and Land]], production of these fertilizers and associated [[land use]] practices are drivers of [[global warming]]. The use of fertilizer has also led to a number of direct environmental consequences: [[agricultural runoff]] which leads to downstream effects like [[Dead zone (ecology)|ocean dead zones]] and waterway contamination, [[soil microbiome]] degradation, and accumulation of toxins in ecosystems. Indirect environmental impacts include: the [[Hydraulic fracturing|environmental impacts of fracking]] for [[natural gas]] used in the [[Haber process]], the agricultural boom is partially responsible for the rapid [[Human population growth|growth in human population]] and large-scale industrial agricultural practices are associated with [[habitat destruction]], [[Biodiversity loss|pressure on biodiversity]] and agricultural [[soil loss]].
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
環境および[[:en:food security|食料安全保障]]への懸念を軽減するため、国際社会は[[:en:Sustainable Development Goal 2|持続可能な開発目標2]]に食料システムを組み込んでおり、これは[[:en:Effects of climate change on agriculture|気候変動に配慮した]][[:en:sustainable food system|持続可能な食料生産システム]]の構築に焦点を当てている。これらの問題に対処するためのほとんどの政策的・規制的アプローチは、農業慣行を[[:en:Sustainable agriculture|持続可能な農業]]または[[:en:Regenerative agriculture|再生型農業]]の慣行へと転換することに焦点を当てている。これらは、合成肥料の使用量を減らし、より良い[[:en:soil management|土壌管理]](例えば[[:en:No-till farming|不耕起農業]])を行い、より多くの有機肥料を使用する。
In order to mitigate environmental and [[food security]] concerns, the international community has included food systems in [[Sustainable Development Goal 2]] which focuses on creating a [[Effects of climate change on agriculture|climate-friendly]] and [[sustainable food system|sustainable food production system]]. Most policy and regulatory approaches to address these issues focus on pivoting agricultural practices towards [[Sustainable agriculture|sustainable]] or [[Regenerative agriculture|regenerative agricultural]] practices: these use less synthetic fertilizers, better [[soil management]] (for example [[No-till farming|no-till agriculture]]) and more organic fertilizers.
For each ton of phosphoric acid produced by the processing of phosphate rock, five tons of waste are generated. This waste takes the form of impure, useless, radioactive solid called [[phosphogypsum]]. Estimates range from 100,000,000 and 280,000,000 tons of phosphogypsum waste produced annually worldwide.
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
=== 水 ===
===Water===
{{Main/ja|:en:Eutrophication}}
{{Main|Eutrophication}}
[[File:Aquatic Dead Zones.jpg|thumb|赤い円は、多くの[[:en:Dead zone (ecology)|デッドゾーン]]の位置と大きさを表す。]]
[[File:Aquatic Dead Zones.jpg|thumb|Red circles show the location and size of many [[Dead zone (ecology)|dead zones]].]]
Phosphorus and nitrogen fertilizers can affect soil, surface water, and groundwater due to the dispersion of minerals into waterways due to high rainfall, snowmelt and can leaching into groundwater over time. Agricultural run-off is a major contributor to the eutrophication of freshwater bodies. For example, in the US, about half of all the lakes are [[eutrophic]]. The main contributor to eutrophication is phosphate, which is normally a limiting nutrient; high concentrations promote the growth of cyanobacteria and algae, the demise of which consumes oxygen. Cyanobacteria blooms ('[[algal blooms]]') can also produce harmful [[Eutrophication#Toxicity|toxins]] that can accumulate in the food chain, and can be harmful to humans. Fertilizer run-off can be reduced by using weather-optimized fertilization strategies.
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
肥料の流出に含まれる''窒素豊富な化合物''は、多くの[[:en:ocean|海洋]]、特に沿岸域、[[:en:lake|湖沼]]、[[:en:river|河川]]における深刻な''酸素欠乏''の主な原因である。結果として生じる溶存酸素の不足は、これらの地域が海洋[[:en:fauna|動物相]]を維持する能力を大幅に低下させる。居住された海岸線近くの海洋[[:en:Dead zone (ecology)|デッドゾーン]]の数は増加している。
The nitrogen-rich compounds found in fertilizer runoff are the primary cause of serious oxygen depletion in many parts of [[ocean]]s, especially in coastal zones, [[lake]]s and [[river]]s. The resulting lack of dissolved oxygen greatly reduces the ability of these areas to sustain oceanic [[fauna]]. The number of oceanic [[Dead zone (ecology)|dead zones]] near inhabited coastlines is increasing.
As of 2006, the application of nitrogen fertilizer is being increasingly controlled in northwestern Europe and the United States. In cases where eutrophication can be reversed, it may nevertheless take decades and significant soil management before the accumulated nitrates in [[groundwater]] can be broken down by natural processes.
Only a fraction of the nitrogen-based fertilizers is converted to plant matter. The remainder accumulates in the soil or is lost as run-off. High application rates of nitrogen-containing fertilizers combined with the high [[water solubility]] of nitrate leads to increased [[Surface runoff#Agricultural issues|runoff]] into [[surface water]] as well as [[Leaching (agriculture)|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.
Nitrate levels above 10 mg/L (10 ppm) in groundwater can cause '[[blue baby syndrome]]' (acquired [[methemoglobinemia]]). Run-off can lead to fertilizing blooms of algae that use up all the oxygen and leave huge "dead zones" behind where other fish and aquatic life can not live.
Soil acidification refers to the process by which the pH level of soil becomes more acidic over time. Soil pH is a measure of the soil's acidity or alkalinity and is determined on a scale from 0 to 14, with [[Seven (1995 film)|7]] being neutral. A pH value below 7 indicates acidic soil, while a pH value above 7 indicates alkaline or basic soil.
Soil acidification is a significant concern in agriculture and horticulture. It refers to the process of the soil becoming more acidic over time. {{See also|Soil pH|Soil acidification}}
Nitrogen-containing fertilizers can cause [[soil acidification]] when added. This may lead to decrease in nutrient availability which may be offset by [[liming (soil)|liming]]. These fertilizers release ammonium or nitrate ions, which can acidify the soil as they undergo chemical reactions.
When these nitrogen-containing fertilizers are added to the soil, they increase the concentration of hydrogen ions (H+) in the soil solution, which lowers the pH of the soil.
The concentration of [[cadmium]] in phosphorus-containing fertilizers varies considerably and can be problematic. For example, mono-ammonium phosphate fertilizer may have a cadmium content of as low as 0.14 mg/kg or as high as 50.9 mg/kg. The phosphate rock used in their manufacture can contain as much as 188 mg/kg cadmium (examples are deposits on [[Nauru]] and the [[Christmas Island]]s). Continuous use of high-cadmium fertilizer can contaminate soil (as shown in New Zealand) and [[Phytotoxicity|plants]]. Limits to the cadmium content of phosphate fertilizers has been considered by the [[European Commission]]. Producers of phosphorus-containing fertilizers now select phosphate rock based on the cadmium content.
Phosphate rocks contain high levels of fluoride. Consequently, the widespread use of phosphate fertilizers has increased soil fluoride concentrations. It has been found that food contamination from fertilizer is of little concern as plants accumulate little fluoride from the soil; of greater concern is the possibility of fluoride toxicity to livestock that ingest contaminated soils. Also of possible concern are the effects of fluoride on soil microorganisms.
The radioactive content of the fertilizers varies considerably and depends both on their concentrations in the parent mineral and on the fertilizer production process. Uranium-238 concentrations can range from 7 to 100 pCi/g (picocuries per gram) in phosphate rock and from 1 to 67 pCi/g in phosphate fertilizers. Where high annual rates of phosphorus fertilizer are used, this can result in uranium-238 concentrations in soils and drainage waters that are several times greater than are normally present. However, the impact of these increases on the [[Sievert#Dose examples|risk to human health]] from radinuclide contamination of foods is very small (less than 0.05 m[[Sievert|Sv]]/y).
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
===== その他の金属 =====
=====Other metals=====
[[zinc/ja|亜鉛]](植物の成長に不可欠)のレベルが高いため肥料にリサイクルされる製鉄産業の廃棄物には、以下の''[[:en:Toxic heavy metal|有毒金属]]''が含まれることがある。[[lead/ja|鉛]]、[[arsenic/ja|ヒ素]]、[[cadmium/ja|カドミウム]]、[[chromium/ja|クロム]]、[[nickel/ja|ニッケル]]である。この種の肥料で最も一般的な有毒元素は、[[Mercury (element)/ja|水銀]]、鉛、ヒ素である。これらの潜在的に有害な不純物は除去できるが、これによりコストが大幅に増加する。高純度肥料は広く入手可能であり、おそらく家庭で使われる青い染料を含む高水溶性肥料、例えば[[:en:Miracle-Gro|ミラクルグロ]]が最もよく知られているかもしれない。これらの高水溶性肥料は植物の苗床事業で使用され、小売量よりも大幅に安価な大型パッケージで入手可能である。一部の安価な小売用粒状園芸肥料は、高純度の成分で作られている。
Steel industry wastes, recycled into fertilizers for their high levels of [[zinc]] (essential to plant growth), wastes can include the following [[Toxic heavy metal|toxic metals]]: [[lead]] [[arsenic]], [[cadmium]], chromium, and nickel. The most common toxic elements in this type of fertilizer are [[Mercury (element)|mercury]], lead, and arsenic. These potentially harmful impurities can be removed; however, this significantly increases cost. 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]]. These highly water-soluble fertilizers are used in the plant nursery business and are available in larger packages at significantly less cost than retail quantities. Some inexpensive retail granular garden fertilizers are made with high purity ingredients.
Attention has been addressed to the decreasing concentrations of elements such as iron, zinc, copper and magnesium in many foods over the last 50–60 years. [[Intensive farming]] practices, including the use of synthetic fertilizers are frequently suggested as reasons for these declines and organic farming is often suggested as a solution. 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. It is, therefore, unlikely that organic farming or reduced use of fertilizers will solve the problem; foods with high nutrient density are posited to be achieved using older, lower-yielding varieties or the development of new high-yield, nutrient-dense varieties.
Fertilizers are, in fact, more likely to solve trace mineral deficiency problems than cause them: In Western Australia deficiencies of [[zinc]], copper, [[manganese]], iron and [[molybdenum]] were identified as limiting the growth of broad-acre crops and pastures in the 1940s and 1950s. Soils in Western Australia are very old, highly weathered and deficient in many of the major nutrients and trace elements. Since this time these trace elements are routinely added to fertilizers used in agriculture in this state. Many other soils around the world are deficient in zinc, leading to deficiency in both plants and humans, and zinc fertilizers are widely used to solve this problem.
Two types of agricultural management practices include organic agriculture and conventional agriculture. The former encourages soil fertility using local resources to maximize efficiency. Organic agriculture avoids synthetic agrochemicals. Conventional agriculture uses all the components that organic agriculture does not use.
Most fertilizer is made from dirty hydrogen. Ammonia is produced from [[natural gas]] and air. The cost of natural gas makes up about 90% of the cost of producing ammonia. The increase in price of natural gases over the past decade, along with other factors such as increasing demand, have contributed to an increase in fertilizer price<!-- over which period? -->.
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
==== 気候変動への寄与 ====
====Contribution to climate change====
{{See also/ja|Greenhouse gas emissions from agriculture/ja}}
{{See also|Greenhouse gas emissions from agriculture}}
[[:en:Haber process|窒素肥料の製造]]および使用中に生成される[[:en:greenhouse gas|温室効果ガス]]([[carbon dioxide/ja|二酸化炭素]]、[[methane/ja|メタン]]、[[nitrous oxide/ja|亜酸化窒素]])の量は、[[:en:anthropogenic greenhouse gas emissions|人為的な温室効果ガス排出量]]の''約5%''と推定されている。そのうち3分の1は生産中に、3分の2は肥料の使用中に生成される。人間による亜酸化窒素排出量(そのほとんどは肥料に由来)は、2007年から2016年の間に年間''700万トン''と推定されており、これは地球温暖化を2°C未満に制限することと両立しない。
The amount of [[greenhouse gas]]es [[carbon dioxide]], [[methane]] and [[nitrous oxide]] produced during the [[Haber process|manufacture]] and use of nitrogen fertilizer is estimated as around 5% of [[anthropogenic greenhouse gas emissions]]. One third is produced during the production and two thirds during the use of fertilizers. Nitrous oxide emissions by humans, most of which are from fertilizer, between 2007 and 2016 have been estimated at 7 million tonnes per year, which is incompatible with limiting global warming to below 2 °C.
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<sub>2</sub>O) has become the third most important [[greenhouse gas]] after carbon dioxide and methane. It has a [[global warming potential]] 296 times larger than an equal mass of carbon dioxide and it also contributes to stratospheric ozone depletion.
[[Methane emissions]] from crop fields (notably rice [[paddy field]]s) are increased by the application of ammonium-based fertilizers. These emissions contribute to global climate change as methane is a potent greenhouse gas.
In Europe, problems with high nitrate concentrations in runoff are being addressed by the European Union's Nitrates Directive. Within [[Great Britain|Britain]], farmers are encouraged to manage their land more sustainably in 'catchment-sensitive farming'. In the [[United States|US]], high concentrations of nitrate and phosphorus in runoff and drainage water are classified as nonpoint source pollutants due to their diffuse origin; this pollution is regulated at the state level. [[Oregon]] and [[Washington (state)|Washington]], both in the United States, have fertilizer registration programs with on-line databases listing chemical analyses of fertilizers. [[Carbon emission trading]] and [[eco-tariff]]s affect the production and price of fertilizer.
In [[China]], regulations have been implemented to control the use of N fertilizers in farming. In 2008, Chinese governments began to partially withdraw fertilizer [[subsidy|subsidies]], including subsidies to fertilizer transportation and to electricity and natural gas use in the industry. In consequence, the price of fertilizer has gone up and large-scale farms have begun to use less fertilizer. If large-scale farms keep reducing their use of fertilizer subsidies, they have no choice but to optimize the fertilizer they have which would therefore gain an increase in both grain yield and profit.
</div>
<div lang="en" dir="ltr" class="mw-content-ltr">
2022年3月、[[:en:United States Department of Agriculture|米国農務省]]は、米国の肥料生産を促進するための2億5000万ドルの新しい助成金を発表した。商品信用公社の一部であるこの助成金プログラムは、主要な肥料供給業者から独立し、米国製であり、将来の競争を促進するために革新的な生産技術を利用する肥料生産を支援する。
In March 2022, the United States Department of Agriculture announced a new $250M grant to promote American fertilizer production. Part of the Commodity Credit Corporation, the grant program will support fertilizer production that is independent of dominant fertilizer suppliers, made in America, and utilizing innovative production techniques to jumpstart future competition.