From Wikipedia, the free encyclopedia Labeling of fertilizer
Labeling of fertilizer
Main article: fertilizer In the UK, fertilizer labeling regulations allow for report-
The labeling of fertilizers varies by country in terms of ing elemental mass fractions of phosphorus and potas-
analysis methodology and subsequently nutrient label- sium. The regulations stipulate this should be done in
ing, and minimum nutrient requirements.[1][2] parentheses after standard NPK values.[4]
Labeling of fertilizers Other fertilizer designations
Fertilizer containing only the three primary macronutri-
Macronutrient fertilizers ents can be referred to as artificial or straight[citation need-
ed]. Compound fertilizers are N-P-K fertilizers with other el-
Macronutrient fertilizers are labeled with an NPK analy- ements purposely intermixed[citation needed]. For example,
sis and also "N-P-K-S" in Australia.[2] However, these a mainly nitrogenous fertilizer mix would be described as
numbers do not directly represent the source composi- a nitrogen fertilizer.
tion or absolute nutrient content of the fertilizer[citation
needed]--macronutrient fertilizers are not labeled by con-
tent but according to traditional analysis. See also
For example, the fertilizer potash is a naturally occur- • Fertilizer
ring mineral composed of nearly pure potassium chloride • NPK values for commercial fertilizers
(KCl). As such, its composition is 1:1 potassium to chloride
or 52% potassium and 48% chlorine by weight (owing to
differences in molecular weight between the elements). References
Traditional analysis of 100g. of KCl would yield 60g. K2O. [1] Chambers, Albert; Sally Rutherford (27 November
The percentage yield of K2O from the original 100g. of fer- 2007). "Voluntary Standards for the Fertilizer and
tilizer is the number shown on the label. A potash fer- Supplements Industry". http://google.com/
tilizer would thus be labeled 0-0-60, not 0-0-52. Many ar- search?q=cache:3KO6Nxn96cMJ:cfpf-fcpf.ca/files/
ticles on the internet will have the wrong succession. It PDF/
should always be nitrogen, phosphorus and potassium. Monachus_presentation.ppt+labeling+of+fertilizer+norway&cd=4&
Lawn specialists and farmers plan their entire growing Retrieved 3 February 2010.
season with the analysis in that order. If, for some odd [2] ^ "Draft Code of Practice for Fertilier Description
reason, it was not in that order, crops and lawns could be and Labeling". Fertilizer Industry Federation
ruined. Always look for NPK. Association (FIFA). 15 September 2008.
Fertilizer is described in this way dating back to http://docs.google.com/
Liebig in the 19th century due to the methods he used viewer?a=v&q=cache:CgW191hwEBIJ:www.fifa.asn.au/
then to compare and evaluate fertilizers[3] files/pdf/regulation/
Draft%2520Code%2520of%2520Practice%2520for%2520Fertilizer%2
Converting nutrient analysis to composition xK0n1g. Retrieved 3 February 2010.
P2O5 consists of 57.4% oxygen and 43.6% elemental phos- [3] Libbert, Dr. Robert "Why phosphorus is expressed
phorus. The percentage ([mass fraction]) of elemental as P2O5 and potassium is expressed as K2O in soil
phosphorus is 43.6% so P= 0.43 x P2O5. K2O consists of tests and fertilizer" 21 December 2008
17% oxygen and 83% elemental potassium. The percent- [4] UK Fertilizers Regulations 1990, Schedule 2 Part 1,
age (mass fraction) of elemental potassium is 83% so K = Para. 7.
0.83 x K2O.
Nitrogen values represent actual nitrogen content so
these numbers do not need to be converted.
Using these conversion factors we determine that
18−51−20 fertilizer contains (by weight):
• 18% elemental (N)
• 22% elemental (P)
• 16% elemental (K)
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From Wikipedia, the free encyclopedia Labeling of fertilizer
Categories:
• Fertilizers
• Packaging
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