Transcript Crop Micronutrients and Soil/Plant Relationships CSS 480

Micronutrients Needed by Crops
Lee Jacobs
Department of Crop and Soil Sciences
Michigan State University
presented at
MWEA Biosolids Conference
Bay City, Michigan
February 21, 2008
Classification of the Essential
Nutrients for Plant Growth
Macronutrients
C, H, O from air and water
N, P, K, Ca, Mg, S from soil
Primary Secondary
Micronutrients
Fe, B, Mn, Cu, Zn, Mo, Cl, Ni from soil
Essential Major Elements – Plants/Animals
Major Plant Nutrients
Major Animal Nutrients
Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
Phosphorus (P)
Potassium (K)
Calcium (Ca)
Magnesium (Mg)
Sulfur (S)
Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
Sulfur (S)
Calcium (Ca)
Phosphorus (P)
Potassium (K)
Magnesium (Mg)
Sodium (Na)
Chlorine (Cl)
Essential Trace Elements – Plants/Animals*
Trace Plant Nutrients
Boron (B)
Copper (Cu)
Iron (Fe)
Manganese (Mn)
Molybdenum (Mo)
Zinc (Zn)
Chlorine (Cl)
Nickel (Ni)
Essential for Some Plants
Cobalt (Co)
Silicon (Si)
Sodium (Na)
Vanadium (V)
Trace Animal Nutrients
Copper (Cu)
Iron (Fe)
Manganese (Mn)
Molybdenum (Mo)
Zinc (Zn)
Arsenic (As)
Chromium (Cr)
Cobalt (Co)
Flourine (F)
Iodine (I)
Nickel (Ni)
Selenium (Se)
Silicon (Si)
Tin (Sn)
Vanadium (V)
* Plants will not only absorb essential plant and animal elements, but many
non-essential elements found in soils are also found in plant tissue ash.
Nutrient Levels in Plants
Terms used to describe nutrient levels in plants:
Deficient – when the concentration of an essential element is low
enough to severely limit yield
Critical range – nutrient concentration in plant below which a
yield response occurs when the essential nutrient is added
Sufficient (optimal) – nutrient concentration range when the yield
will not increase when more of the essential nutrient is added,
but plant tissue concentration can increase
Excessive (toxic) – when the concentration of an essential, or
non-essential, element is high enough to reduce plant growth
and yield
(a)
(b)
Figure 2.5. Typical dose-response curves for (a) essential elements (macronutrients & micronutrients)
and (b) non-essential elements. (Alloway,1995, p. 31)
(1% = 10,000 ppm)
Havlin et al.,2005, p. 12
Quantities of Micronutrients Needed
1) While micronutrients are required by a plant for
growth, the amount needed is small in comparison
to macro nutrients (N, P, K).
2) Nevertheless, deficiency of a micronutrient can be
just as yield limiting as the deficiency of a
macronutrient.
Micronutrients
Element
Chloride (Cl)
Iron (Fe)
Manganese (Mn)
Zinc (Zn)
Form Taken
up by plants
ClFe2+, Fe3+
Mn2+
Zn2+
Boron (B)
Copper (Cu)
H3BO3
Cu2+
Molybdenum (Mo)
Nickel (Ni)
MoO42Ni2+
Major
Source
Precipitation
Salts
Soil minerals
Soil minerals
Soil minerals,
organic matter
Organic matter
Soil minerals
organic matter
Soil minerals
Soil minerals
Concentration
in plants (avg)
100 ppm
100 ppm
50 ppm
20 ppm
20 ppm
6 ppm
0.1 ppm
0.01 ppm
For optimum availability of all essential plant nutrients, usually want to maintain
soil pH at 6.5 or above by liming, but soil pH should be kept below 7.0.
Typical Concentrations in Soils
Micronutrient
Iron (Fe2+, Fe3+)
Manganese (Mn2+)
Nickel (Ni2+)
Zinc (Zn2+)
Copper (Cu2+)
Range
0.5 – 50%
20 – 3,000 ppm
2 – 750 ppm
10 – 300 ppm
2 – 100 ppm
Average
3 – 4%
600 ppm
50 ppm
50 ppm
9 ppm
Boron (H3BO3)
2 – 200 ppm
50 ppm
Molybdenum (MoO42-)
Chloride (Cl-)
0.2 – 5.0 ppm
1.2 ppm
highly variable
Similar cycles occur for each of the cationic micronutrients, as shown above for Fe2+
and Fe3+, except only divalent forms of Mn2+, Zn2+, Cu2+, and Ni2+ are taken up by
plants.
Havlin et al., 2005, p. 245
Fe and Mn in Soils
1) Solubility of Fe minerals is very low in soils, so Fe3+ in solution is
very low and much higher than Fe2+ in well-drained, oxidized soils
across common soil pH’s.
2) Under waterlogged conditions, Fe3+ can be reduced to Fe2+
2 Fe2O3  4 FeO + O2
3) Mn2+ is common in soil solution, but concentrations decrease as pH
increases.
4) Mn2+ concentration controlled mostly by MnO2, w/ ~90% of the Mn2+
organically complexed (chelated); Mn2+ in solution can increase
under acid, reducing conditions
5) Natural organic compounds in soil, or synthetic compounds added
to soils can complex (chelate) Fe3+, which can increase Fe in the
soil solution and transport to roots by mass flow and diffusion.
Havlin et al., 2005, p. 250
MSU Extension
Bulletin E-486
Table 1. Micronutrient sufficiency ranges in diagnostic tissue of selected crops.**
Element
Corn
-
-
Wheat
-
-
-
-
Alfalfa
-
-
Soybeans
-
- ppm -
Potatoes
-
-
-
-
Sugar Beets
-
-
-
-
Boron (B)
Copper (Cu)
Iron (Fe)
4-25
6-20
21-250
6-40
6-50
11-300
31-80
11-30
31-250
21-55
10-30
51-350
15-40
7-30
30-300
26-80
11-40
51-200
Manganese (Mn)
Molybdenum (Mo)
Zinc (Zn)
20-150
0.1-2.0
20-70
16-200
0.03-5.0
21-70
31-100
1.0-5.0
21-70
21-100
1.0-5.0
21-50
30-200
0.5-4.0
30-100
21-150
0.15-5.0
19-60
Chloride (Cl)
Nickel (Ni)
2,000-20,000 (0.2-2.0%)
0.1-1.0
** Ranges taken from MSU Bulletin E-486, page 2, except general range for Cl and Ni taken from Havlin et al, 2005.
-
Fe Deficiency Symptoms and
Toxicity in Plants
1) Plants contain 11-350 ppm. Deficiency not common for field
and vegetable crops grown on soils with pH <7.0
2) Fe is very immobile in plants, so deficiency symptoms appear
in young leaves, causing stunted growth.
3) Young leaves develop interveinal chlorosis, similar to Mn
deficiency.
4) Under severe Fe deficiency, leaves turn white and eventually
die (necrosis).
5) Fe toxicity where plants accumulate >300 ppm can occur when
pH is <5.0 and where soils are contaminated w/ soluble Fe
salts.
Figure 23. Iron-deficient corn. Light yellowing of the terminal leaves, with
interveinal chlorosis of the leaves similar to that caused by Mn deficiency.
Seldom found in Michigan field crops. More commonly found in woody plants,
ornamental and turf crops. (Bull. E-486, p. 14)
Fe deficiency in a fescue lawn. (personal communication, J.L. Havlin)
Mn Deficiency Symptoms and
Toxicity in Plants
1) Plants contain 20-200 ppm Mn (normal), usually deficient if <20
ppm, and usually toxic if >300 ppm.
2) Mn deficiency usually found on slightly acid (pH 6.6-7.0) or
alkaline soils (pH >7.0); may also occur when:
a) pH >5.8 on organic soils & black sands
b) pH >6.5 on mineral soils
2) Mn is immobile in plants, so deficiency symptoms appear in
young leaves.
3) Young leaves develop interveinal chlorosis, similar to Fe
deficiency.
4) Mn toxicity occurs in sensitive crops grown on acid soils; liming
can readily correct this problem – in tissue, Mn concentrations
>300 ppm can be toxic
Havlin et al., 2005
Figure 4. Manganese-deficient dark red kidney beans. Yellowing between the
leaf veins. Veins remain green. (Bull. E-486, p. 7)
Typical Concentrations in Soils
Micronutrient
Iron (Fe2+, Fe3+)
Manganese (Mn2+)
Nickel (Ni2+)
Zinc (Zn2+)
Copper (Cu2+)
Range
0.5 – 50%
20 – 3,000 ppm
2 – 750 ppm
10 – 300 ppm
2 – 100 ppm
Average
3 – 4%
600 ppm
50 ppm
50 ppm
9 ppm
Boron (H3BO3)
2 – 200 ppm
50 ppm
Molybdenum (MoO42-)
Chloride (Cl-)
0.2 – 5.0 ppm
1.2 ppm
highly variable
Similar cycles occur for Cu2+ and Ni2+, as shown above for Zn2+, to release divalent
ions of each metal into the soil solution for uptake by plants.
Havlin et al., 2005, p. 256
Zn, Ni and Cu in Soils
1) Soil solution Zn2+, Ni2+, and Cu2+ is low; Zn, Ni and Cu solubility is
pH dependent, as shown in the figure earlier.
2) Organic complexed (chelated) forms of Zn2+, Ni2+, and Cu2+ can
increase the concentrations of each metal in the soil solution to
increase their diffusion to roots for plant uptake.
Havlin et al., 2005, p. 250
Zn, Ni and Cu in Soils
1) Soil solution Zn2+, Ni2+, and Cu2+ is low; Zn, Ni and Cu solubility is
pH dependent, as shown in the figure above.
2) Organic complexed (chelated) forms of Zn2+, Ni2+, and Cu2+ can
increase the concentrations of each metal in the soil solution to
increase their diffusion to roots for plant uptake.
3) Availability of Cu is more strongly controlled by soil organic matter
(SOM). At <8% SOM, Cu is adsorbed to organic & mineral
surfaces, but at >8% SOM, Cu is adsorbed mostly on organic
surfaces. Therefore, Cu deficiency is frequent w/ peat & muck
soils.
Zn and Ni Deficiency Symptoms
and Toxicity in Plants
1) Zn deficiency is usually found on soils that are a) acidic sandy soils
low in Zn, b) neutral, basic, or calcareous soils, and c) soils with high
available P. Ni deficiency is seldom observed due to low plant
requirements.
2) Zn and Ni are not readily translocated, so deficiency symptoms first
appear in young leaves.
3) Zn and Ni toxicity can occur on acid soils, pH <5.0, and/or where soils
are contaminated with soluble Zn or Ni salts.
4) Zn concentrations are normally 20-150 ppm with <20 ppm being
deficient and >300 ppm being toxic.
5) Ni concentrations are normally 0.1-1.0 ppm with >50 ppm usually
toxic. However, some plants are hyperaccumulators of Ni and leaves
of these plants can contain >1,000 ppm w/o toxicity.
Figure 13. Zinc-deficient corn. Yellow or white striping of the leaves usually
developing near the stalk. Plants are often stunted with shortened internodes.
Found most often on high pH soils and organic soils. (Bull. E-486, p. 10)
Havlin et al.,
2005
Cu Deficiency Symptoms and
Toxicity in Plants
1) Cu deficiencies are not as common as other micronutrients but can
occur in sensitive crops on low-Cu soils, because most soils in
Michigan have sufficient Cu. Peaty soils are generally the only soils
that can be deficient in Cu.
2) Cu is not readily translocated, so deficiency symptoms first appear in
young leaves.
3) Cu toxicity is uncommon but can occur where soils are contaminated
with high Cu materials or repeated use of Cu-containing pesticides.
4) Plants contain 6-50 ppm Cu with 5-20 ppm being normal, <6 ppm
usually deficient, and >150 ppm usually toxic.
Typical Concentrations in Soils
Micronutrient
Iron (Fe2+, Fe3+)
Manganese (Mn2+)
Nickel (Ni2+)
Zinc (Zn2+)
Copper (Cu2+)
Range
0.5 – 50%
20 – 3,000 ppm
2 – 750 ppm
10 – 300 ppm
2 – 100 ppm
Average
3 – 4%
600 ppm
50 ppm
50 ppm
9 ppm
Boron (H3BO3)
2 – 200 ppm
50 ppm
Molybdenum (MoO42-)
Chloride (Cl-)
0.2 – 5.0 ppm
1.2 ppm
highly variable
A similar cycle occurs for H3BO3 and MoO42- as for Cl-. Note that leaching is a possible
pathway; however, no H3BO3 and MoO42- inputs from rain occur, as occurs with Cl-.
Havlin et al., 2005, p. 280
B, Mo and Cl in Soils
1) Total B in soils varies between 2-200 ppm, while total Mo in soils
typically ranges between 0.2-5 ppm. Nearly all Cl- in soils exists in
the soil solution, which ranges in concentration from 0.5 ppm in acid
soils to >6,000 ppm in saline/sodic soils.
2) H3BO3 is the predominant form in soil solution at pH range of 5 to 9.
Organically complexed B is the largest potential source of plant
available B in soils, which increases w/ increasing SOM.
3) MoO42-, HMoO4-, and H2MoO4 are forms found in soil solution with
MoO42- and HMoO4- concentrations increasing as soil pH increases.
4) Cl in soils behaves very similar to NO3-, being very soluble and
readily leaches.
B, Mo and Cl Deficiency Symptoms
and Toxicity in Plants
1) B deficiency is usually found on sandy soils, organic soils & some
fine-textured lake bed soils (w/ alkaline subsoils). Very few soils in
MI have need for Mo additions, except for peats, acid sandy soils &
organic soils w/ large amounts of bog Fe. Deficiency of Cl is rare.
2) B and Mo are immobile in plants, so deficiency symptoms appear in
young leaves.
3) B toxicity is uncommon in most arable soils, unless excess amounts
are added by fertilizers or contamination. Plants normally contain
20-100 ppm B with <15 ppm usually being deficient and >200 ppm
usually being toxic.
B, Mo and Cl Deficiency Symptoms
and Toxicity in Plants (cont’d)
4) Plants normally contain 0.8-15 ppm Mo with <0.5 ppm usually being
deficient. Plants appear quite tolerant of high soil Mo, so there are
no recordings of Mo toxicity under field conditions. However,
excess amounts of Mo in forages are toxic to animals causing
molybdenosis, a disease in cattle.
5) Plants normally contain 0.5-2.0% Cl (5,000-20,000 ppm) with <70700 ppm usually indicative of deficiency. Concentrations up to
2.0% can be toxic for sensitive plants and >4.0% can be toxic for
tolerant plants, although levels as high as 10% do occur with some
salt-tolerant plants.
Soil Testing and Fertilizer Additions of
Micronutrients
1) In Michigan, soil testing can be done for B, Cu, Fe, Mn and Zn
to check for adequate availability of these nutrients for plant
growth.
2) When availability is low, the following are rates normally
recommended for crops that are:
nutrient
highly responsive
medium responsive
B
1.5 - 3.0 lb/ac
0.5 – 1.0 lb/ac
Cu
3 – 6 lb/ac (organic soils) 1.5 – 3.0 lb/ac
Fe
(foliar spray usually used at 0.5 – 1.0 lb/ac)
Mn
(4 – 8 lb/ac for mineral, 8 – 16 lb/ac for organic soils)
Zn
(3-5 lb/ac for soil pH>7.5, 2-3 lb/ac for soil pH 6.7-7.4)