Labeling of fertilizer

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Many countries have standardized the labeling of fertilizers to indicate their contents of major nutrients. [1] [2] The most common labeling convention, the NPK or N-P-K label, shows the amounts of the chemical elements nitrogen, phosphorus, and potassium.

Contents

Common labeling conventions

The NPK analysis label

Fertilizers are usually labeled with three numbers, as in 18-20-10, indicating the relative content of the primary macronutrients nitrogen (N), phosphorus (P), and potassium (K), respectively.

More precisely, the first number ("N value") is the percentage of elemental nitrogen by weight in the fertilizer; that is, the mass fraction of nitrogen times 100. The second number ("P value") is the percentage by weight of phosphorus pentoxide P
2
O
5
. The third number ("K value") is the equivalent content of potassium oxide K
2
O
. [3]

For example, a 15-13-20 fertilizer would contain 15% by weight of nitrogen, 13% by weight of P
2
O
5
, 20% by weight of K
2
O
, and 52% of some inert ingredient.

Other labeling conventions

In the U.K., fertilizer labeling regulations allow for reporting the elemental mass fractions of phosphorus and potassium. The regulations stipulate that this should be done in parentheses after the standard N-P-K values, as in "15-30-15 (15-13-13)". [4]

In Australia, macronutrient fertilizers are labeled with an "N-P-K-S" system, which uses elemental mass fractions rather than the standard N-P-K values and includes the amount of sulfur (S) contained in the fertilizer. [5]

Fertilizers with additional macronutrients (S, Ca, Mg) may add more numbers to the N-P-K ratio to indicate the amount. The additional numbers are similarly reported in the oxide mass fraction form. For example, a Polish fertilizer labeled "NPK (Ca,S) 4-12-12 (14-29)" has an equivalent of 14% soluble calcium oxide and 29% total sulfur trioxide. [6]

Converting nutrient analysis to composition

The values in an NPK fertilizer label are related to the concentrations (by weight) of phosphorus and potassium elements as follows:

The N value in NPK labels represents actual percentage of nitrogen element by weight, so it does not need to be converted.

So, for example, an 18−51−20 fertilizer contains by weight

As another example, the fertilizer sylvite is a naturally occurring mineral consisting mostly of potassium chloride, KCl. Pure potassium chloride contains one potassium atom (whose atomic mass is 39.09 g/mol) for every chlorine atom (whose atomic mass is 35.45 g/mol). Therefore, pure KCl is 39.09/(39.09 + 35.45) = 52% potassium and 48% chlorine by weight. Its K value is therefore 52/0.83 = 63; that is, a fertilizer that gets all its potassium from K
2
O
and has the same potassium contents as pure KCl would have to be 63% K
2
O
. Pure KCl fertilizer would thus be labeled 0-0-63. Since sylvite contains other compounds that contribute no N, P, or K, it is usually labeled 0-0-60.

NPK values for commercial fertilizers

NPK values for various synthetic fertilizers [7]

NPK values for mined fertilizer minerals

NPK values for biosolids fertilizers and others

See also

Related Research Articles

<span class="mw-page-title-main">Phosphorus</span> Chemical element with atomic number 15 (P)

Phosphorus is a chemical element; it has symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Earth. It has a concentration in the Earth's crust of about one gram per kilogram. In minerals, phosphorus generally occurs as phosphate.

<span class="mw-page-title-main">Phosphate</span> Anion, salt, functional group or ester derived from a phosphoric acid

In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid, a.k.a. phosphoric acid H3PO4.

<span class="mw-page-title-main">Fertilizer</span> Substance added to soils to supply plant nutrients for a better growth

A fertilizer or fertiliser is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from liming materials or other non-nutrient soil amendments. 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 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.

<span class="mw-page-title-main">Plant nutrition</span> Study of the chemical elements and compounds necessary for normal plant life

Plant nutrition is the study of the chemical elements and compounds necessary for plant growth and reproduction, plant metabolism and their external supply. In its absence the plant is unable to complete a normal life cycle, or that the element is part of some essential plant constituent or metabolite. This is in accordance with Justus von Liebig's law of the minimum. The total essential plant nutrients include seventeen different elements: carbon, oxygen and hydrogen which are absorbed from the air, whereas other nutrients including nitrogen are typically obtained from the soil.

<span class="mw-page-title-main">Diammonium phosphate</span> Chemical compound

Diammonium phosphate (DAP; IUPAC name diammonium hydrogen phosphate; chemical formula (NH4)2(HPO4)) is one of a series of water-soluble ammonium phosphate salts that can be produced when ammonia reacts with phosphoric acid.

<span class="mw-page-title-main">Organic fertilizer</span> Fertilizer developed from natural processes

Organic fertilizers are fertilizers that are naturally produced. Fertilizers are materials that can be added to soil or plants, in order to provide nutrients and sustain growth. Typical organic fertilizers include all animal waste including meat processing waste, manure, slurry, and guano; plus plant based fertilizers such as compost; and biosolids. Inorganic "organic fertilizers" include minerals and ash. Organic refers to the Principles of Organic Agriculture, which determines whether a fertilizer can be used for commercial organic agriculture, not whether the fertilizer consists of organic compounds.

<span class="mw-page-title-main">Struvite</span> Magnesium ammonium phosphate mineral

Struvite (magnesium ammonium phosphate) is a phosphate mineral with formula: NH4MgPO4·6H2O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platy mica-like forms. It is a soft mineral with Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7. It is sparingly soluble in neutral and alkaline conditions, but readily soluble in acid.

<span class="mw-page-title-main">Urine</span> Liquid by-product of metabolism in the bodies of many animals, including humans

Urine is a liquid by-product of metabolism in humans and in many other animals. In placental mammals, urine flows from the kidneys through the ureters to the urinary bladder and is ejected from the penis or vulva through the urethra during urination. In other vertebrates, urine is excreted through the cloaca.

<span class="mw-page-title-main">Urea phosphate</span> Chemical compound

Urea phosphate is a 1:1 combination of urea and phosphoric acid that is used as a fertilizer. It has an NPK formula of 17-44-0, and is soluble in water, producing a strongly acidic solution.

<span class="mw-page-title-main">Ocean fertilization</span> Type of climate engineering

Ocean fertilization or ocean nourishment is a type of technology for carbon dioxide removal from the ocean based on the purposeful introduction of plant nutrients to the upper ocean to increase marine food production and to remove carbon dioxide from the atmosphere. Ocean nutrient fertilization, for example iron fertilization, could stimulate photosynthesis in phytoplankton. The phytoplankton would convert the ocean's dissolved carbon dioxide into carbohydrate, some of which would sink into the deeper ocean before oxidizing. More than a dozen open-sea experiments confirmed that adding iron to the ocean increases photosynthesis in phytoplankton by up to 30 times.

<span class="mw-page-title-main">Mangalore Chemicals & Fertilizers</span>

Mangalore Chemicals & Fertilizers Limited is the largest manufacturer of chemical fertilizers in the state of Karnataka, India. The company is part of the Adventz Group. The company's corporate and registered office is at UB City, Bangalore and its factory unit is in Panambur, north of Mangalore.

<span class="mw-page-title-main">Controlled-release fertiliser</span> Fertiliser that releases nutrients gradually

A controlled-release fertiliser (CRF) is a granulated fertiliser that releases nutrients gradually into the soil. Controlled-release fertilizer is also known as controlled-availability fertilizer, delayed-release fertilizer, metered-release fertilizer, or slow-acting fertilizer. Usually CRF refers to nitrogen-based fertilizers. Slow- and controlled-release involve only 0.15% of the fertilizer market (1995).

<span class="mw-page-title-main">Ammonium dihydrogen phosphate</span> Chemical compound

Ammonium dihydrogen phosphate (ADP), also known as monoammonium phosphate (MAP) is a chemical compound with the chemical formula (NH4)(H2PO4). ADP is a major ingredient of agricultural fertilizers and dry chemical fire extinguishers. It also has significant uses in optics and electronics.

Phosphate rich organic manure is a type of fertilizer used as an alternative to diammonium phosphate and single super phosphate.

<span class="mw-page-title-main">History of fertilizer</span>

The history of fertilizer has largely shaped political, economic, and social circumstances in their traditional uses. Subsequently, there has been a radical reshaping of environmental conditions following the development of chemically synthesized fertilizers.

<span class="mw-page-title-main">Chicken manure</span> Feces of chickens used as an organic fertilizer, especially for soil low in nitrogen

Chicken manure is the feces of chickens used as an organic fertilizer, especially for soil low in nitrogen. Of all animal manures, it has the highest amount of nitrogen, phosphorus, and potassium. Chicken manure is sometimes pelletized for use as a fertilizer, and this product may have additional phosphorus, potassium or nitrogen added. Optimal storage conditions for chicken manure include keeping it in a covered area and retaining its liquid, because a significant amount of nitrogen exists in the urine.

Haifa Group is a private international corporation which primarily manufactures Potassium Nitrate for agriculture and industry, specialty plant nutrients and food phosphates. Haifa Group (Haifa) is the world pioneer in developing and supplying Potassium Nitrate and Specialty Plant Nutrients for advanced agriculture in various climates, weather, and soil conditions. Haifa also manufactures Controlled Release Fertilizers (CRF) for agriculture, horticulture, ornamentals, and turf. Many of Haifa's fertilizers can be used as a fertilizer solution that is applied through drip irrigation. This latter application is the principal driver of demand today, now that more countries are turning to controlled irrigation systems that make more efficient use of water.

<span class="mw-page-title-main">Ammonium carbamate</span> Chemical compound

Ammonium carbamate is a chemical compound with the formula [NH4][H2NCO2] consisting of ammonium cation NH+4 and carbamate anion NH2COO. It is a white solid that is extremely soluble in water, less so in alcohol. Ammonium carbamate can be formed by the reaction of ammonia NH3 with carbon dioxide CO2, and will slowly decompose to those gases at ordinary temperatures and pressures. It is an intermediate in the industrial synthesis of urea (NH2)2CO, an important fertilizer.

<span class="mw-page-title-main">Reuse of human excreta</span> Safe, beneficial use of human excreta mainly in agriculture (after treatment)

Reuse of human excreta is the safe, beneficial use of treated human excreta after applying suitable treatment steps and risk management approaches that are customized for the intended reuse application. Beneficial uses of the treated excreta may focus on using the plant-available nutrients that are contained in the treated excreta. They may also make use of the organic matter and energy contained in the excreta. To a lesser extent, reuse of the excreta's water content might also take place, although this is better known as water reclamation from municipal wastewater. The intended reuse applications for the nutrient content may include: soil conditioner or fertilizer in agriculture or horticultural activities. Other reuse applications, which focus more on the organic matter content of the excreta, include use as a fuel source or as an energy source in the form of biogas.

Seventeen elements or nutrients are essential for plant growth and reproduction. They are carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), sulfur (S), calcium (Ca), magnesium (Mg), iron (Fe), boron (B), manganese (Mn), copper (Cu), zinc (Zn), molybdenum (Mo), nickel (Ni) and chlorine (Cl). Nutrients required for plants to complete their life cycle are considered essential nutrients. Nutrients that enhance the growth of plants but are not necessary to complete the plant's life cycle are considered non-essential, although some of them, such as silicon (Si), have been shown to improve nutrent availability, hence the use of stinging nettle and horsetail macerations in Biodynamic agriculture. With the exception of carbon, hydrogen and oxygen, which are supplied by carbon dioxide and water, and nitrogen, provided through nitrogen fixation, the nutrients derive originally from the mineral component of the soil. The Law of the Minimum expresses that when the available form of a nutrient is not in enough proportion in the soil solution, then other nutrients cannot be taken up at an optimum rate by a plant. A particular nutrient ratio of the soil solution is thus mandatory for optimizing plant growth, a value which might differ from nutrient ratios calculated from plant composition.

References

  1. Chambers, Albert; Sally Rutherford (27 November 2007). "Voluntary Standards for the Fertilizer and Supplements Industry" . Retrieved 3 February 2010.[ dead link ]
  2. "Draft Code of Practice for Fertilier Description and Labeling". Fertilizer Industry Federation Association (FIFA). 15 September 2008. Retrieved 3 February 2010.
  3. nutrient_analysis www.flairform.com 22 October 2014 Archived 28 October 2014 at the Wayback Machine
  4. UK Fertilizers Regulations 1990, Schedule 2 Part 1, Para. 7.
  5. "National Code of Practice for Fertilizer Description & Labelling" (PDF). Australian Government Department of Agriculture, Fisheries and Forestry. Archived from the original (PDF) on 28 February 2015. Retrieved 27 October 2014.
  6. "NPK (Ca,S) 4-12-12 (14-29) Lubofoska". skladrolny.pl. Retrieved 15 December 2022. Lubofoska is a fertilizer applied before sowing...
  7. NPK (Fertilizer) chemicalland21.com accessed 15 December 2022
  8. 1 2 3 4 J. B. Sartain, University of Florida, "Food for turf: Slow-release nitrogen", Grounds Maintenance, archived from the original on 29 October 2019, retrieved 28 October 2014
  9. "Fertiliser labels explained". RHS Advice. Royal Horticultural Society. Retrieved 31 October 2021.
  10. Bat and seal guano are lower in fertilizer value than bird guano. see Guano
  11. George Rehm; Michael Schmitt; John Lamb; Gyes Randall; Lowell Busman (2002). "Understanding Phosphorus Fertilizers". University of Minnesota Extension Service. Archived from the original on 5 September 2013. Retrieved 28 October 2014.
  12. 1 2 3 from "Average total N, ammonium N, phosphate and potash content of manure at the time of land application" in Animal Manure As a Plant Nutrient Resource, Bulletin ID-101 (Reviewed 02/05/01), Cooperative Extension Service, Purdue University. West Lafayette, IN 47907 "ID-101". Archived from the original on 12 March 2012. Retrieved 28 October 2014.
  13. Organic Fish, Blood and Bone Feed – Harrod Horticultural (UK) www.harrodhorticultural.com accessed 15 December 2022