Soil and Plant Factors in Availability of CA

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Soil and plant factors in availability of Ca

Some principles of Ca :

- Derived from limestone bedrock

- It is found in many primary and secondary minerals in the soil

- Often insoluble

- Not a leachable nutrient

- TIME = movement to the depths; thus a higher pH and higher Cacontent in the subsoils

The same general principles apply to the behavior of Magnesium (Mg) asapply to Calcium (Ca) and Potassium (K)


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www.soils.wisc.edu/extension/teaching material s/Peters/Liming%20basics.ppt -


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The low ability of the plant to take up calciumcoincides with the large amount in most soils.

Available calcium is measured in terms of thousandsof pounds/acre, while other nutrients are present at

hundreds of pounds/acre, and often much less.Except under conditions of severe calcium deficiencyin the soil, no relation exists between the amount of

Calcium in the soil and the amount in the plant. Furthermore, like potassium, not much calcium is

required by soil organisms. (Parnes, 1990)


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Factors in availability of Ca

Total exchangeable Calcium (Ca) supplySoil pHCEC% Ca saturation of Soil colloidsType of soil colloid/ Parent materialRatio of Ca to other cations in the solution

- ex: Ca/Mg

Soil physical characteristicsMicro organisms


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Soil pH: soil acidity; not exactly how

available the acidity is for use by the plants;this is dependent on CEC

-Acidic soils have less Ca

-Alkaline soils have more Ca

-As soil pH increases beyond 7.2, additionalfree Ca is not absorbed into thesoil unless CEC is increased as well

-Free Ca often forms insoluble compoundswith other elements such as Phosphorous(P) making them less available

The addition of calcium carbonate and limingraise soil pH to make it more basic

http://www.bionaturefertilizer.com/BNE%20Soil%20pH%20scale.gif

The only substances whicheffectively neutralize soilwithout disrupting cationbalance are Ca, or Ca + Mg

Depending upon Mg content ofthe soil


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Soil pH



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www.soils.wisc.edu/extension/teaching material s/Peters/Liming%20basics.ppt -


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A quick rundown of Cation Exchange Capacity (CEC):

Cation exchange is when very fine clay/humus particles (- negativecharge), attract cations (+)

How?

-Micelles; loosely attract cations

-Cations associated with the micelles form the pool ofexchangeable cations; those in the soil solution form the solublecations

Cation exchange reservoir = the number of micelles

Cation exchange capacity = the number of cations in the reservoir


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CEC:

More soil OM = more soil particles = more CEC

- Liming acid soils increases CEC by creating a reservoir

- As Hydrogen (H+) on humus is neutralized by liming, thesite where it was attached attains a negative charge and canhold on to Ca++, Mg++, K+, etc.

** plants are less sensitive to Ca concentrations, so Caplays a major role in maintaining the balance btwn acid andalkaline conditions.


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Parent material:

Soils derived from

LIMESTONE, MARL high Ca levels

SHALE, SANDSTONE low Ca levelshttp://www.historyforkids.org/learn/arts/limestone.htm

http://www.zionnationalpark.com/zioninfo/photos/Sandstone-2.jpg


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Soil physical factors: moisture, aeration, temperature


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Micro-organisms:


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Leaching of Ca

Ca = the most dominant cation in drainagewaters, streams, and lakes

- Sodium may be lost most readily from soil, but Ca islost in the greatest quantity- Leaching losses from Ca = 75 200 lbs/A per year


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Plants that love Ca

All plants need calcium.

It is involved with:

- maintenance of cell walls and membranes

- ion balance

- intracellular signaling

Plants that are likely to suffer Ca deficiency:

peanuts, tomatoes, celery, soybeans

Plants with high Ca requirements:

alfalfa, cabbage, potatoes, and sugar beets

http://www.ens-newswire.com/ens/aug2005/20050810_beet.jpg

http://www.nutbrothers.com/Pictures/Products/PEANUTS.JPG


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Soil and plant factors in availability of Ca and MgTying Ca and Mg together

Exchangeable Aluminum (Al 3+):

- Dominant in soil with pH


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Exchangeable Aluminum (Al3+):

http://hubcap.clemson.edu/~blpprt/acid1.html

-Organic matter ties up aluminum and chelates many trace elements

-pH is not as important with high OM

The East and Oregon (acidic soils) toxic levels of Al

Southwest and West soils low in Al

Organic soils low Al

Concentration of Al in the soilsolution based upon:- Soil pH- Al saturation of effective CEC- Salt concentration of the system


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Soil and plant factors in availability of Ca and Mg Tying Ca and Mg together

Cation ratios Ca/ Mg:

- Wide range of Ca:Mg ratio = plant deficient of Mg

- Ratio should not be greater than 7:1 (Ca:Mg)

-Healthy Ca:Mg ratios stimulate earthworm populations andmicroorganisms

Horror scenario:

Humid region, coarse textured soils; receive high application levels ofcalcic liming materials huge Ca:Mg ratio Mg deficiency


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Soil and plant factors in availability of Ca and Mg Tying Ca and Mg together

Cation ratios K/Mg:

- High levels of exchangeable Potassium (K) will interfere with Magnesium(Mg) uptake by plants

- Problem in low Mg soils

- IDEAL RATIOS of K:Mg

< 5:1 for field crops

3:1 for vegetables and sugarbeets

2:1 for fruits and greenhouse crops


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Amount of Mg present

Soil pH

Degree of Mg saturation

Nature of other exchangeable ions

Type of clay

Seasonal and environmental conditions

*The same general principles apply to the behavior of Magnesium (Mg) asapply to Calcium (Ca) and Potassium (K)

Factors in availability of Mg


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Soil and plant factors in availability of Mg

Amount of Mg present:

- An antagonistic relationship exists btwen Ca, Mg, and K

- all compete to be taken up by the root

-Mg rarely present as a soil amendment, often falls short

-Deficiencies do not cause yield loss, unless drastic


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Soil pH:

Low pH decreases Mg availability; High pH increases availability

Balance between Ca, Mg, and K is crucial

Excessive Potassium (K) Mg deficiency (and Ca deficiency too inacidic soils)

- Soil should ideally have as many Mg ions as Potassium (K)ions


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CEC:

Similarly to Calcium (Ca)

- Low CEC soils hold less Mg and High CEC soils hold more!

- OM adds mobility to Mg levels in the soil


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Parent material/ Type of clay:

- Clays are unfavorable for Mg CEC

- Compost = great source of Mg


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Seasonal and Environmental Conditions affecting Mg availability:

Mg deficiency caused by

- A Cool, cloudy, wet growing season

- Humid conditions

- Old weathered soils


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Leaching of Mg

- Losses depend upon the interactions of the following:

- Mg content of the soil

- rate of weathering

- intensity of leaching

- uptake by plants

- Ave losses = 5 60 lbs/A per year

- Severe problem in sandy soils

-humid conditions blah!

- Few problems occur when equal amounts of Potassium (K) are appliedas carbonates, bicarbonates, or phosphates


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Plants that love Mg

Highly responsive plants:

pastures, corn, potatoes, oil palm, cotton, citrus, tobacco, sugar beets

Apple varieties highly susceptible to deficiencies:

Newtown, Macintosh, and Spartan

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https://reader010.{domain}/reader010/html5/0611/5b1e1d751e219/5


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Grass Tetany A nutritional disorder in cattle caused by lack of Mg in their diet,

and in their blood serum; often associated with low Ca levels in blood

- Caused by high levels of exchangeable elements (such as Al); andLOW Mg in plants

- Effects females only

- Older cows more susceptible than younger

Symptoms

- Death

- Nervousness, muscletremors, salivation, rapidbreathing

http://www.hubbardfeeds.com/nmg/beef/beef_tetany.shtml


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Solutions

- Application of properly balanced fertilizers and Mgcompounds to grass

- Dust Mg compounds directly onto plants for consumptionby the cattle

- Preventing disorder completely by supplying the animalswith Mg supplements

Grass Tetany

S il d l f i il bili f C d M


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Use the following factors to make fertilizer recommendations:

-Total exchangeable amount of Ca

-Total exchangeable amount of Mg

-pH

-CEC and % saturation

-Exchangeable Al

-Cation ratio of Ca:Mg

-Cation ratio of K:Mg

-Soil physical factors: moisture, aeration, temperature-Micro-organisms


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Works Cited

Rankins, Darrell Jr. Management Practices to Reduce Grass Tetany. Alabama Cooperative Extension System. Online.http://www.aces.edu/pubs/docs/A/ANR-0495/ . 5 March 2007
http://www.aces.edu/pubs/docs/A/ANR-0495/http://www.aces.edu/pubs/docs/A/ANR-0495/http://www.aces.edu/pubs/docs/A/ANR-0495/http://www.aces.edu/pubs/docs/A/ANR-0495/


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Visuals CitedWhittington, David. Grass Tetany, the Silent Killer of Spring. Hubbard Feeds

Inc. Online. http://www.hubbardfeeds.com/nmg/beef/beef_tetany.shtml . 5March 2007

The Government of Brunei Darussalam Official Website. Liming of Soil. Online. http://www.agriculture.gov.bn/website2003/ninformation/fact15.htm .

5 March 2007
http://www.hubbardfeeds.com/nmg/beef/beef_tetany.shtmlhttp://www.agriculture.gov.bn/website2003/ninformation/fact15.htmhttp://www.agriculture.gov.bn/website2003/ninformation/fact15.htmhttp://www.hubbardfeeds.com/nmg/beef/beef_tetany.shtml


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Soil and Plant Factors in Availability of CA