Nutrient Management

Analytical Research Laboratory

Extension Soil Testing Laboratory

Soil and Water Science Department

Manure Testing Laboratory

 

Essential Nutrients and Ionic Forms

Essential Elements

Essential Nutrients

Naturally Occurring Elements

Elemental Abundance in Plant Tissue

Sufficiency Ranges

 

Essential Elements

What is an Essential Element?

The number of elements considered essential for the growth of higher plants now varies from 16 to 20 or more, depending upon the definition of essentiality. The authors of this book are aware that Arnon* limits essentiality to only those elements that are needed for higher plants to complete all life functions and that the deficiency can be corrected by the application only of this specific element causing the deficiency. Other scientists such as Nicholas believe that an element should be considered essential if its addition enhances plant growth even though it merely substitutes for one of the 16 elements that Arnon declares to be essential. For example, because sodium can substitute in plant nutrition for some potassium, and vanadium for some molybdenum, Nicholas would consider both sodium and vanadium as essential, but Arnon would not. On the basis of the criteria used, Arnon specifies 16 elements and Nicholas 20 elements as being essential for the growth of higher plants such as cotton and corn. Three other debated nutrients are nickel (urea transformations), cobalt (N2 fixation), and silicon. (See Chapter 8 for further information on essential elements for plants.)

D. I. Arnon, "Mineral Nutrition of Plants," Annual Review of Biochemistry, 12 (1943), pp. 493 528.
D. J. D. Nicholas, "Minor Mineral Elements," Annual Review of Plant Physiology, 12 (1961), pp. 63 90

 

Criteria of Essentiality

Arnon (1954)

Plant cannot complete a function and cannot complete its life cycle

A deficiency can be corrected only by application of the specific element that is deficient

The element plays a direct role in metabolism

Boron	Copper	Molybdenum	Silicon
Calcium	Hydrogen	Nitrogen	Sodium
Carbon	Iron	Oxygen	Sulfur
Chlorine	Magnesium	Phosphorus	Vanadium
Cobalt	Manganese	Potassium	Zinc

 

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Essential Nutrients

From soil, water, and air

Carbon C0₃^-2, HCO₃ , CO₂

Hydrogen H⁺, OH^-

Oxygen O₂, OH^-

Primarily from soil: macro or major, secondary, and micrometabolic or trace elements

Nitrogen NO₃^- , NH₄⁺

Phosphorus HPO₄^-2, H₂PO₄^-

Potassium K⁺

Calcium Ca⁺²

Magnesium Mg⁺²

Sulfur SO₄^-2

Iron Fe⁺² , Fe⁺³

Copper Cu⁺² , Cu⁺

Zinc Zn⁺²

Manganese Mn⁺² , MnO₄^-

Molybdenum HMoO₄^- , MoO₄^-2

Boron H₃BO₃, B₄O₇^-2

Chlorine Cl^-

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Naturally Occurring Elements

Element	Symbol	Atomic No.	Atomic Weight	Element	Symbol	Atomic No.	Atomic weight
Hydrogen*	H	1	1.008	Silver	Ag	47	107.87
Helium	He	2	4.003	Cadmium	Cd	48	112.4
Lithium	Li	3	6.94	Indium	In	49	114.82
Beryllium	Be	4	9.012	Tin	Sn	50	118.7
Boron	B	5	10.81	Antimony	Sb	51	121.75
Carbon	C	6	12.01	Tellurium	Te	52	127.6
Nitrogen	N	7	14.007	Iodine	I	53	126.9
Oxygen	O	8	15.999	Xenon	Xe	54	131.3
Fluorine	F	9	18.998	Cesium	Cs	55	132.91
Neon	Ne	10	20.179	Barium	Ba	56	137.34
Sodium	Na	11	22.99	Lanthanum	La	57	138.91
Magnesium	Mg	12	24.305	Cerium	Ce	58	140.12
Aluminum	Al	13	26.98	Praseodymium	Pr	59	140.91
Silicon	Si	14	28.08	Neodymium	Nd	60	144.24
Phosphorus	P	15	30.97	Promethium	Pm	61	[145.]**
Sulfur	S	16	32.06	Samarium	Sm	62	150.4
Chlorine	Cl	17	35.45	Europium	Eu	63	151.96
Argon	A	18	39.948	Gadolinium	Gd	64	157.25
Potassium	K	19	39.102	Terbium	Tb	65	158.9
Calcium	Ca	20	40.08	Dysprosium	Dy	66	162.5
Scandium	Sc	21	44.96	Holmium	Ho	67	164.93
Titanium	Ti	22	47.9	Erbium	Er	68	167.26
Vanadium	V	23	50.94	Thulium	Tm	69	168.9
Chromium	Cr	24	51.996	Ytterbium	Yb	70	173.04
Manganese	Mn	25	54.94	Lutetium	Lu	71	174.97
Iron	Fe	26	55.85	Hafnium	Hf	72	178.49
Cobalt	Co	27	58.93	Tantalum	Ta	73	180.94
Nickel	Ni	28	58.71	Tungsten	W	74	183.85
Copper	Cu	29	63.55	Rhenium	Re	75	186.2
Zinc	Zn	30	65.37	Osmium	Os	76	190.2
Gallium	Ga	31	69.72	Iridium	Ir	77	192.2
Germanium	Ge	32	72.6	Platinum	Pt	78	195.09
Arsenic	As	33	74.92	Gold	Au	79	197
Selenium	Se	34	78.96	Mercury	Hg	80	200.59
Bromine	Br	35	79.904	Thallium	Ti	81	204.37
Krypton	Kr	36	83.8	Lead	Pb	82	207.2
Rubidium	Rb	37	85.47	Bismuth	Bi	83	209
Strontium	Sr	38	87.62	Polonium	Po	84	[209]
Yttrium	Y	39	88.91	Astatine	At	85	[210]
Zirconium	Zr	40	91.22	Radon	Rn	86	[222]
Niobium	Nb	41	92.91	Francium	Fr	87	[223]
Molybdenum	Mo	42	95.94	Radium	Ra	88	226.03
Technetium	Tc	43	98.91	Actinium	Ac	89	[227]
Ruthenium	Ru	44	101.07	Thorium	Th	90	232.04
Rhodium	Rh	45	102.91	Protactinium	Pa	91	231
Palladium	Pd	46	106.4	Uranium	U	92	238.03

* Elements in bold type essential to plants

** Values in brackets are mass nos. of most stable known isotope.

 

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Elemental Abundance in Plant Tissue

_{Average elemental composition of corn tissue (silage). From Troeh, Frederick and L. M. Thompson. 1993. Soils and soil fertility. Oxford University Press. New York.}

Element	Corn silage
	ppm, dry wt.	%, dry wt.
oxygen	450,000	45
carbon	440,000	44
hydrogen	63,000	6.3
nitrogen	13,000	1.3
silicon	12,000	1.2
potassium	9,000	0.9
calcium	2,500	0.25
phosphorus	1,600	0.16
magnesium	1,600	0.16
sulfur	1,500	0.15
chlorine	1,500	0.15
aluminum	1,100	0.11
sodium	300	0.03
iron	90	0.009
manganese	60	0.006
zinc	30	0.003
boron	10	0.001
copper	5	0.0005
molybdenum	1	0.0001

Be aware that elemental concentrations in plant tissue can vary widely for a given crop depending on the stage of growth and environmental conditions and for different crops, yet plants can still appear normal and healthy. For some elements the range of sufficiency is wide and for others the range is narrow. A good deal of caution needs to be exercised in diagnosing mineral deficiencies based only on plant tissue analysis.

 

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Sufficiency Ranges

_{The following tables are based on data presented in Soil Testing and Plant Analysis Edited by Leo M. Walsh and James D. Beaton, published by Soil Science Society of America, Madison, Wisconsin, 1973.}

Sufficiency ranges for soybean leaves, based on data from Ohio State University Plant Analysis Laboratory, 1971.

Element Sufficiency Range
N, %	4.26 - 5.50
P, %	0.26 - 0.50
K, %	1.71 - 2.50
Ca, %	0.36 - 2.00
Mg, %	0.26 - 1.00
Mn, ppm	21 - 100
Fe, ppm	51 - 350
B, ppm	21 - 55
Cu, ppm	10 - 30
Zn, ppm	21 - 50
Mo, ppm	1 - 5

 

Sufficiency ranges reported for corn:

Element Sufficiency Range
N, %	2.6 - 5.0
P, %	0.25 - 0.8
K, %	1.7 - 5.0
Ca, %	0.21 - 1.6
Mg, %	0.21 - 0.8
S, %	0.2 - 0.5
Al, ppm	0 - 200
B, ppm	6 - 20
Cu, ppm	6 - 20
Fe, ppm	21 - 300
Mn, ppm	20 - 200
Mo, ppm	0.6 - 1.0
Zn, ppm	20 - 150

Sufficiency ranges reported for small grains:

Element Sufficiency Range
N, %	1.25 - 3.0
P, %	0.15 - 0.50
K, %	1.25 - 3.0
Ca, %	0.2 - 1.2
Mg, %	0.15 - 0.50
S, %	0.15 - 0.40
Cu, ppm	5 - 25
Mn, ppm	5 - 100
Zn, ppm	15 - 70

 

Sufficiency ranges reported for cotton:

Element Sufficiency Range
N, %	3.0 - 4.5
P, %	0.30 - 0.65
K, %	0.9 - 3.0
Ca, %	1.90 - 3.50
Mg, %	0.30 - 0.90
B, ppm	20 - 60
Cu, ppm	8 - 20
Fe, ppm	30 - 300
Mn, ppm	30 - 350
Zn, ppm	20 - 100

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Reference Materials

Soils: An Introduction to Soils and Plant Growth. 6th Edition. Donahue, Miller, and Shickluna.

Soil Fertility and Fertilizers, 3rd Edition. Tisdale and Nelson. 1975. Macmillan Publishing Co., Inc. New York, NY.

Soil Acidity and Liming, 2nd Edition. F. Adams. 1984. ASA, Madison, WI.

Soils and Soil Fertility. Troeh, Frederick and L.M. Thompson. 1993. Oxford University Press. New York, Ny.