The Healthy Soil Foodweb as a Foundation for Biodynamic Farming By James E. Miller for Undergraduate Research supervised by Dr. Bruce Maxwell, Department of Agriculture, Montana State University July 8, 2004

1. OVERVIEW
   
   1. General:

Biodynamic farming is currently a niche player in the grand scheme of production of food and fodder in North America. The antecedent system has been in place for centuries, has continued in third world countries, has gained substantial popularity in Europe and has established a respectable beach head in North America. Basically, the system returns to the soil, biomass which, through breakdown and consolidation, contributes nutrients and soil tilth. This paper serves as a point of entry for novice farmers and gardeners, but quickly leads to soil chemistry and soil microbial action intended for the more advanced student of soil science. Much of the current knowledge is aimed at the farmer, gardener and general population; hence, much of the written material is highly repetitive and does not provide many of the answers which serious science demands. This paper examines the state of science found in selected repositories of biodynamic farming knowledge with the intent to find tested theories relating to base cation exchange rates, limiting reactions in soil chemistry and microbial competition and cooperation.

2. Summary Definition:

Bio-Dynamic Farming is defined as the use of native, non-synthesized, mineral soil amendments, humus from compost and green manures, and microbiota in a soil foodweb which provides the maximum values for plant use. Inputs to the soil foodweb require green manure, well composted manure and carbon, frequent test of soil minerals and microbiota, testing of plant material and addition of specific minerals to achieve the optimum balance for a given crop. Biodynamic farming also includes land management practices, such as crop rotation, and animal practices, such as frequent pasture changes. Three areas of soil conditions which most affect the health of the soil foodweb are examined: Base cation exchange rate, limiting reactions which favor or disfavor proper soil chemical balance, and competition and cooperation among microbes and plants. [BDF-NZ 2004]. i

3. Base cation exchange rate:

The base cation exchange rate is the rate at which soil atoms and molecules combine or disjoin to achieve equilibrium. In chemistry terms, the study involves the oxidation - reduction reaction. Included in the basic study are the effects of buffering agents to stabilize compounds as acidity changes. Weak acids produced by soil biota break down minerals which make them more available to uptake by plants. [WSU 2001] ii Thus, the kind and numbers of soil biota become important in determining the proper balance of soil minerals. Soil minerals also can act as enzymes and catalysts to promote or retard microbial action. Metrics are applied to the base cation exchange rate in terms of mini-equivalents of electrical current. The effects of various levels of the base cation exchange rate can also be observed in the population of soil biota and the resulting effect on plant growth and health in empirical studies. [WSU 2001] iii

4. Limiting reactions:

An excess or deficiency of one mineral can have a major impact on the availability of other necessary minerals to sustain the proper balance of soil minerals and nutrients. This paper investigates whether and to what extent theories of limiting reactions, when applied to soil chemistry, have a good scientific basis and are supported by experimental testing. [Johnson, Cheng and Burke 2000] iv

5. Microbial activity:

Microbial activity greatly influences the health of the soil foodweb. The kind and number of soil biota is the subject of substantial critical inquiry. The area which appears to be least recognized and studied is the effect on soil health when certain microbes successful suppress other soil biota or enhance it by a symbiotic relationship. This paper examines the state of that research. [Vadakattu 2002] v

2. INTRODUCTION TO BIODYNAMIC FARMING SCIENCE
   
   1. Overview:

The practical application of native nutrients and tilth, leads to substantial scientific studies of the soil foodweb. The best example of this outcome is the work of Dr. Elaine Ingram who has done pioneering work on identifying and counting members of the microbial communities in the soil food web. [Ingram 1999] vi

2. A Very Short History:
   
   1. Marcus Porcius Cato: One of the earliest commentators on the use of biodynamic farming practices was a Roman Senator and agriculturalist, Marcus Porcius Cato, born in 234 BC. His directions to his farm managers that all manure must first be composted, and then used on the plants, was very specific.

“Be sure to have a big manure heap. Store every bit of dung. Sort it and break it down as you shift it. Cart it out in autumn. Autumn is the time to trench round your olive trees and dung them.” [Dalby undated] vii

2. Rudolph Steiner: The next most important commentator was Rudolph Steiner, a German scientist and philosopher. Steiner’s main contribution to the science side of biodynamic farming was his opposition to the use of industrial chemicals in farming. [Kheper, 1998] viii
3. Dr. William A. Albrecht:

“Dr. Albrecht was Professor of Soils and Chairman of the Department of Soils at the University of Missouri College of Agriculture for many years. He had gained this position after he had earned four academic degrees - A.B., B.S., M.S. and Ph.D., all from the University of Illinois. He wrote extensively for a variety of scientific and agricultural journals.” Dr. Albrecht’s main contribution was the advancement of the science relative to base cation exchange rate, soil mineral balance, soil tilth and trace elements. [Albrecht Republished 1975 - 1996] ix

4. Siegfried and Uta Luebkes; Ehrenfreid Pfieffer:

Siegfried’s passion as a soil biologist was the collection of over 3,600 microbe-driven enzyme reactions in soils and compost. The Luebkes, working in collaboration with Dr. Ehrenfried Pfieffer, developed the circular chromatogram which tests evaluate the humus condition of soils and composts. [Diver 1999] x

1. Additional resources on the history of biodynamic farming:
   
   1. National Agricultural Library, Tracing the Evolution of Organic-Sustainable Agriculture, http://www.nal.usda.gov/afsic/AFSIC_pubs/tracing.htm
   2. An Ecological History of Agriculture: 10,000 B.C. to A.D. 10,000, by Daniel E. Vasey, 1992. http://ianrwww.unl.edu/ianr/csas/v6ch4.htm#4-3
1. Point of entry:

The most comprehensive compendium of publications on biodynamic farming is Resource Guide to Organic & Sustainable Vegetable Production, 2001, by Steve Diver. 10

3. BASE CATION EXCHANGE RATE BASICS
   
   1. Reactants and Products:

Reactants and products reach equilibrium in a bidirectional exchange of ions. The rate of such exchange is based in part on the relative eletroactivity of the atoms and coll. molecules, as influenced by the changing conditions of acidity; heat; relative concentrations of solutes and solvents and, in the cases of solids, surface areas, and gases, pressure. [Gardiner 2004] xi

2. Cation exchange capacity: A detailed analysis is done to determine the cation exchange capacity of the soil and is measured in milliequivalents. The CEC affects the colloid’s capacity to hold nutrients such as calcium, magnesium and ammonia nitrogen. A CEC of 10 in sandy soil will hold twice the poundage of nutrients than a CEC of 5. [Kinsey 1999] 12 In a laboratory test, the CEC of the soil must be measured separately to determine the amount of calcium, magnesium, potassium and sodium it can hold. [Kinsey 1999] xii
3. Remineralization: Trees which have undergone generations of acid rain and other stresses have died, especially those in the northeast, east and southeast where coal is the main source of fuel for large power plants. [Bruck 1992]xiii An experiment conducted by Dr. Robert Bruck, professor of plant pathology at No. Carolina St. University in the early 1990’s indicated that a well-balanced remineralization of the soil reduced mortality and increased growth rates. [Bruck 1992] 13

One wonders if remineralization is simply the addition of clay, in pellet form, found in an ancient lake bed, such as in Flathead Valley. Remineralization is simply replacing the “fines” which were washed down from the mountains into the rivers and then into the lake bottoms over eons.

4. Introduction to double substitutions and limiting reactions: In chemistry we learned to predict and find the limiting element in a chemical reaction, then, by removing the spectator ions, [ions which are the same on both sides of the equation; they cancel out] we could derived the net chemical reaction. We could find how much of one atom or molecule was needed to completely react with a given quantity and type of another reactant. Kinsey discusses generally the limiting factors, but not in chemical formula terms. [Kinsey 1999] xiv
5. Limiting reaction defined and overview:

There are two concepts of limiting reaction as applied to plant growth. In a double substitution reaction, one of the reactant elements is exhausted and the other reactant is in excess. [Burns 2003] xv This approach deals with the relative quantities of reactants. When there is an excess of one of the reactants left over, the one consumed is said to be the limiting reactant. [Burns 2003] xvi The second concept is one whereby the mere presence of a chemical in a double substitution reaction, inhibits the other reactant, even if the quantities are sufficient. As viewed by the plant, too much of one nutrient, mineral may be too much even if other nutrients are present in abundance. [Kinsey 1999] 14

6. Chemical Equilibrium:

Most chemical reactions, except for combustion, are reversible. Single or double substitutions of reactant positive ions on the left side of the equation with counter-part bases on the left side of the equation, can go both ways (left and right) simultaneously. Reactions stop when the concentrations of reactants and their products are the “same” on both sides of the equation. [Burns 2003] xvii Seldom is the soil food web static. The constant changes give rise to chemical kinetics which refers to the rate of the reactions. Before atoms, ions and molecules can react, they have imparted to them the energy of activation so that when they collide with the proper orientation the reactions will take place. The rate of reaction is determined by the collision frequency. The higher the level of the energy of activation, the more frequently will the collisions occur. [Burns 2003] xviii For instance, when two hydrogen atoms react to form a hydrogen molecule, the orientation is not important because they have no front, back or sides. However, for most chemical reactions, the orientation of the atoms is critical to the successful collision. For example, when nitrogen dioxide, NO2, reacts with carbon monoxide, CO, to form nitrous oxide, NO, and carbon dioxide, CO2, if the oxides collide, a reaction will occur. If the nitrogen collides with the oxide, no reaction will occur. [Burns 2003] xix Follow the URL to a Flash animation of the showing results of proper and improper orientation: http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/collis11.swf

7. Sources of energy of activation in the soil foodweb:
   
   1. Effect of catalysts on reaction rates:

Many trace elements act as catalysts in reducing the amount of energy it takes to cause a reaction to occur, or obversely, catalysts increases the rate of reactions by spreading the available energy over more reactions (the faster the atoms bounce around, the more collisions, the more reactions). [Burns 2003] xx

2. Effect of enzymes on reaction rates: the Krebs Cycle:

The major source of energy in plant metabolism is the electron discharge when ATP changes to ADP. The reaction is known as the Krebs cycle. Enzymes help this process by speeding the reaction. [Crotty, 1994] xxi In a simplified explanation, the Krebs cycles changes plant sugars into electrons which are packaged as “ATP” when are then physically transported from the leaves to the plants, down the branches, stems and trunks to the roots where the ATP releases the electrons at the right time and in the right place to furnish the energy of activation. A more technical explanation is offered by Campbell and Reece. [Campbell and Reece 2002] xxii

3.7.3. ATP Yield from Metabolism of Glucose:

http://www.people.virginia.edu/~rjh9u/atpyield.html

3.7.4. Diagram of Electron Transport Portion of Energy Metabolism:

http://www.people.virginia.edu/~rjh9u/eltrans.html

8. Examples of limiting reactions from out-of-balance minerals:

Some of the other side effects of imbalance of nutrients are: Improper balance of calcium and magnesium permit organic residue to decay into alcohol (sterilant) or formaldehyde (preservative). The latter is evident when last years turned-under corn stalks are just a fresh as when earlier plowed under. [Fenzau 1971] xxiii Excess application of nitrogen consumes calcium and “burns-up” the humus, resulting in depletion of the humus and poor crop years after the first windfalls from excess nitrogen. [Fenzau 1971] 23 Excess minerals during the growing stage can plug-up stem vessels and cause early death. [Fenzau 1971] 23 Excess magnesium and nitrogen inhibit the crop from growing dry and eventually ripening the seeds or fruit. [Fenzau 1971] 23 An important source of CO2, in addition to air-bourn, is the conversion of carbon in the soil by soil biota. More than 30% of CO2, needed by a plant is thought to come from the soil. Nutrients of the soil foodweb must be adequate and balanced to feed the soil biota. [Fenzau 1971] 23 Clay soils, high in magnesium (typical) and low in calcium (typical) create a cement so tight that air and water cannot penetrate, the result of which are hard clumps of soil or soil like concrete. Crusting prevents the in soak of water. Chemicals in liquid form which need to penetrate the soil but applied to the top of the crust do not penetrate but simply vanish with the wind, rain and irrigation. Soil lacking in tilth does not produce healthy plants and good yields. [Fenzau 1971] 23 Topdressing ninety miles of desert with 60 cents worth of bluestone salt, increased the sheep forage fourfold. [Fenzau 1971] 23 “Bluestone” is a solution of copper sulfate which provided a trace of copper which promotes the effective use of phenothiazine for sheep health and lamb production. An indicator of copper deficiency in black sheep is that the fleece turns grayish, plus the wool fiber changes from a soft crimp to a fine, harsh “steel wire”. Further, without the trace copper, sheep develop “brittle bones”. [Fenzau 1971] 23

9. Microbial contributions to balanced reactions:

Bacteria, fungus, Actinomycetes, and other soil biota breakdown raw materials into gums, waxes, lignins and ultimately, simple sugars, fulvic acid, humic acid and humins, the process of which is defined as “humifiction”. [Pettit 2002] xxiv Effective humus or friable humus supplies slow-release nutrients over a period of time of weeks or months by creating short-chain humic compounds. “Stable humus” is more permanent and has a half-life in years, and consists of long chain humic compounds. [Midwest April 2004] xxv One goal is to produce humus which is insoluble in water, thus preventing leaching. [Nutra-Tech 1998] xxvi When microbes attach the long chain compounds, they create nooks and crannies associated with clay-humus which provide shelter for the microbes and voids which are filled with air or water. [Grundmann et al. 2001] xxvii In exchange for the shelter and food, the microbes produce lignin which cements the very fine soil particles together to form “aggregates”. [Beck 1997] xxviii This process produces a soil “crumb” which greatly increases soil tilth. [Beck 1997] 28 Siegfried Luebke, a microbiologist, and his wife, Uta, experimented with microbes and developed a database of over 3,600 microbe-driven enzyme reactions in soils and compost. From years of planting, growing and experimentation, they developed a “Humus Management System”. The main result was “CMC Compost”, an inoculum for starting compost operations. [Diver 1999] xxix They observed two phases: breakdown and buildup. The breakdown phase feeds on green manure, compost and other soil organisms, aided by addition of the inoculum and light tillage. [Diver 1999] xxx

10. Electronegativity:

Plants have a nutrient delivery system which depends, in part, on the ability of atoms and molecules to move up the food chain from minerals to solutions containing plant nutrient. Defined, electronegativity is a measure of the tendency of an atom in a co-valent bond to attract shared electrons to itself. [Burns 2003] xxxi Electronegativity affects the rate at which the breakdown of minerals and their transformation occurs in a water solution. The more electroactive an atom is, the faster it will react and the more completely it will react with its conjugate base or conjugate proton. Relative acidity influences the rate of base cation exchange, although not exclusively. [Burns 2003] xxxii

11. Trace element effect on plant growth:

Water solutions entering the plant root system carries Nitrogen (N) Potassium (K), and Phosphorus (P) which are needed by the plant. Nitrogen is made available to the plant in the form of nitrate when the pH is above 5.5. Phosphorus requires a pH of 6.0 or better. Certain bacteria live in the root nodules of legumes which convert atmospheric nitrogen into nitrate, hence the reputation that legumes are good green manure for replenishing nitrogen in the soil. Hence, the rate of nitrogen deposition is affected by the relative health of the bacterial colonies in the root nodules of the legumes. The more nutrients available to the bacteria, the more nitrogen is fixed in the soil. The rate of breakdown of the minerals into forms usable by the bacteria depends, in large part on the available rate of activation energy. [Ben-Jacob 1995] xxxiii

12. Nutrient balance. Crops, wind, precipitation take minerals from the soil. Sustainable agriculture means that the base cation exchange rate is at the optimum when minerals are kept in proportion to each other and meet the minimum needs of the plants. An example of the nutrient mineral balance and replacement rate recommended for corn and cotton is:

	Range in soil	ESTIMATED CROP REMOVAL
Nutrient	(total lb/acre)	Corn (150 bu)	Cotton (1000 lb lint)
Boron	20-200	0.06	0.05
Copper	2 -400	0.05	0.03
Iron	10,000 – 200,000	0.10	0.07
Manganese	100 – 10,000	0.08	0.03
Molybdenum	1 – 7	0.03	0.02
Zinc	20.600	0.15	0.06

[Kinsey 2003] xxxiv

1. Soil tilth: Soil tilth is the measure of the “openness” of the soil and its granulation. The more granular, the more open. An excess of Magnesium “tightens” the soil where as additions of Calcium “loosens” the soil. Addition of compost loosens the soil as does the actions of microbes, worms and other soil critters. Plants also loosen the soil by driving roots into the soil, and then when they die, the decomposed roots provide pathways for air, water and soil critters. The more the tilth, the faster and more extensively will a plant’s rooting system spread, thus giving the plant greater access to nutrients. Addition of well composted materials is most likely the best practice to increase soil tilth. Organic growers typically prefer organic compost to any other means of adding to soil tilth as well as adding to the nutrient content of their growing grounds. [Oregon Tilth 2001] xxxv
1. COMPETITION
   
   1. Chemical competition:

“Two types of injury may occur: (1) An excess of one element may lead to a deficiency of another which ultimately results in a deranged metabolism, e.g., excess nitrogen or excess phosphorus may result in insufficient potassium and excess potassium may lead to deficiency of magnesium or calcium. This type of injury applies particularly to essential nutrients. ( 2 ) The presence of an element may directly injure the protoplasm and bring about the speedy death of the plant.” [Wallace 1943] xxxvi Thus, too much or too little of a nutrient can adversely affect plant health and yield. Neal Kinsey advises that sodium molybate can supply a short fall of molybdendum, but it should not be applied if copper levels are deficient. [Kinsey 2003].xxxvii Chlorine is necessary for photosynthesis. Sensitive crops such as tomatoes, lettuce, barley, alfalfa and sugar beets will show tip wilt and leaf chlorosis and necrosis. [Kinsey 2003] xxxviii

2. pH as a limiting factor:

The rate at which major contributors to pH levels contribute to or detract from plant health depends, in part, on the “competition” between them. For example, pound for pound, magnesium can raise the pH up 1.67 times as high as calcium. A soil high in magnesium and low in calcium can test above 6.5 but will be inadequate for growth of legumes because the legume bacteria do not have adequate calcium. However, when calcium and magnesium are in equilibrium, the soil is a proper environment for healthy growth of bacteria and fungus so as to promote decay of residue into CO2, carbonic acid and other weak acids. These acids are necessary to break down minerals into useable soils nutrients. [Fenzau 1971] xxxix

3. Complexity of the soil biota and the relationship to soil productivity. As the kind and number of soil biota increases, so does the productivity of the soil.
   
   1. Nemotodes:

“Nematodes are a group of tiny roundworms that demonstrate the wide diversity and the inextricable food web that exists in a healthy soil. Twenty thousand species have been described, but half a million species may exist. Most soil nematodes eat bacteria, fungi, protozoa, and other nematodes, making them important in nutrient cycling.” [UMES 2000] xl

2. Fungus:

“Fungi prey on nematodes in a number of ways. They trap them with their sticky appendages or squeeze them (like a boa constrictor) in fungal mechanical ring traps. Some fungi exude a toxin to quiet their struggling prey.” [UMES 2000] 40

3. Arthropods:

The predator population of protozoa, nematodes, microarthropods, and earthworms perform mineralization to humus and are in turn eaten by millipedes, centipedes, beetles, spiders, and small mammals. [Ingram 1999] xli

4. Range of soil biota and plant health:

Nutrient rich soil tends develop, over time, a community rich in microbiota. As the soil biomass become more mature, the health of the plants increases. [Ingram 2001] xlii

4. Competition studies:
   
   1. Mediators:

Studies have been conducted to pinpoint the ability of established bacteria to gain competitive advantage in the rhizosphere of plants by secreting mediators. “However, when they are reintroduced into the environment, they are normally out-competed by the already present, well-adapted microflora in this habitat.” [Rossbach Undated] xliii

2. Plant-microbe competition:

A study was undertaken to determine the controlling factors in limiting uptake of nitrogen in tundra. The findings were that plants exploited the available soil nutrients during the growing early growing season, while soil microorganisms exploited the soil nutrients later in the season. [Jaeger 1999] xliv

5. Antibiotics:

Soil microbiota have defense mechanisms to eliminate competition for food in the nature of antibiotics. These defenses have been harvested for medical purposes. [Osburne and associates 1999] xlv

1. Soil foodweb health and the ecosystem: As the health of the soil foodweb increases, so does the health of the ecosystem which depends on the soil foodweb. [Ingram 1999] xlvi
2. Soil Foodweb Significance: Biomass or minerals which are considered “waste” to our consumer-based society, can become a valuable input to the soil foodweb through several means: Composing, vermiculture, reduction of sewerage sludge, fines from mining and gravel operations, and plant extracts, to name a few. To the extent that these inputs supplant additions of industrial or “toxic” chemicals, the ecosystem is both economically efficient and healthier. [ Life Undated] xlvii
3. Endophytes: Dr. Gary Strobel, Montana State University, is one of the leading scientists to study endophytes. Endophytes inhabit the stems and seeds of grasses and other plants without harming the host. They create amino acids which tend to fight-off pathogens which attack the plant. [Strobel 2003] xlviii
1. CONCLUSION

What has been reported about the soil food web, as early as Cato, has, by a preponderance of the evidence, sufficient scientific underpinnings to justify the economic risk of full-fledged biodynamic farming. The agricultural basis for industrial chemicals should give way to farming based on naturally occurring organic inputs, such as compost, minerals, worms and well designed and tested inoculums. The results will include healthier plants, greater yield, lower input costs, less pollution, less soil loss and healthier up-chain food consumers. Universities and other scientific organizations should devote more resources to filling in the gaps of knowledge about the soil foodweb and less to industrial chemical uses. Government funding should sift from commodity agriculture which depends heavily on industrial chemicals and intensive cropping, to cropping using less chemically and machine intensive means. Government funding of research should shift to funding worthy projects such as that undertaken by Drs. Strobel and Bruck. APPENDIX 1 BASE CATION EXCHANGE RATE Northern Arizona University; Lecture 13; ENV 320 http://jan.ucc.nau.edu/~doetqp-p/courses/env320/lec13/Lec13.html Chapter 5:158-168 Clay Minerals (cont.) 1. Ion Exchange in Soils:

	As a result of negative charges developed by soil colloids ions are absorbed on the surfaces of these colloids in soils.
	The ions absorbed are include Ca2+, Mg2+, K+, Al3+, and Na+.
	In humid regions Ca2+, Al3+ and H+ are by far the most numerous cations absorbed.
	Al3+ and H+ tend to dominate in humid regions.
	In semi arid regions Ca2+, Mg2+, K+, and Na+ tend to dominate.

2. Sources. Negative Charge:

	The main source of charge on clay minerals is isomorphous substitution which confers permanent charge on the surface of most layer silicates.
	Ionization of hydroxyl groups on the surface of other soil colloids and organic matter can result in what is describes as pH dependent charges-mainly due to the dependent on the pH of the soil environment. Unlike permanent charges developed by isomorphous substitution, pH-dependent charges are variable and increase with increasing pH.
	Presence of surface and broken - edge -OH groups gives the kaolinite clay particles their electronegativity and their capacity to absorb cations.
	In most soils there is a combination of constant and variable charge.

3. Cation Exchange:

	Displacement of one cation by another results in the process called cation exchange.
	For example: H+ produced by organic acid.
	Under high rainfall conditions, Ca leached reaction goes to right.
	Under low rainfall conditions, Ca and other soils are not easily leached.
	Reaction doses go to completion and tend to go to the left.

4. Factors Affecting Cation Exchange:

	The charge of the ion. Generally ions with higher valency will exchange for those of lower valency. For example Al3+ > Ca2+ > Mg2+ > K+=NH4+ >Na+ .
	For ions of same charge, the cation with the smallest hydrated radius is strongly absorbed because it moves close to the site of charge. For examples K with a hydrated radius of 0.532 nm, will exchange for Na , hydration radius of O.790 nm, on the exchange sites.
	The rate of ion exchange in soils is affected by the type and quantity of organic and inorganic colloids. Clay minerals with 1:1 lattice tend to have more rapid rate of exchange than 2:1 clays which have both internal and external exchange sites.

5. Cation Exchange Capacity:

	The cation exchange capacity of soils (CEC) is defined as the sum of positive (+) charges of the adsorbed cations that a soil can adsorb at a specific pH.
	Cation Exchange Capacity (CEC) is expressed as centimoles of positive charge per kilogram (cmol kg-1), of oven dry soil...
	Earlier unit was meq per 100 g soils.
	Equivalent weight : Quantity that is chemically equal to 1 gram of H.
	Number of H in equivalent weight is 6.02 x 1023 or Avoagardo's number.
	Milliequivalent is equal to 0.001gm of H.
	Example 6.02 X 1020 charges.
	Total cation exchange capacity of the soil is the total number of exchange sites of both the organic and mineral colloids.

http://jan.ucc.nau.edu/~doetqp-p/courses/env320/lec13/Lec13.html 6. Estimating CEC and Exchangeable Cations. (Refer to in text) 7. Table 13.1 Cation Exchange Capacities of Clay Minerals

Colloid Type	CEC (cmol Kg-1)
Kaolinite	2-15
Montmorillonite	80-150
Chlorite	10-40
Vermiculite (Trioctahedral)	100-200
Vermiculite (Dioctahedral)	10-150
Allophane	3-250
Gibbsite	4
Goethite	4

Adapted From Sparks 1995. Environmental Chemistry of Soils. Academic Press. 8. Cation Exchange Capacities of Soils

	The CEC of a given soil is determined by the relative amounts of different colloids in that soil and by the CEC of each of these colloids.
	Sandy soils generally have lower CEC than clay soil because coarse textured soils have lower amounts of both clays and organic matter.

Table 13.2

Soils Order	CECs (cmol kg-1)	pH
Ultisols	3.5	5.6
Alfisols	9.0	6.0
Spodosols	9.3	4.93
Mollisols	18.7	6.51
Vertisols	35.6	6.72
Aridisols	15.2	7.26
Inceptisols	14.6	6.08
Entisols	11.6	7.32
Histosols	128.0	5.50

Adapted From Holmgren et al. (1993). J. Environ. Qual. 22:335-348

9. Importance of Cation Exchange

Cation exchange at negative sites is major retention mechanism for heavy metals, e.g. Cd, Pb and Zn.

10. Measurement of CEC.

	The CEC of soil is usually measured by saturating the soil with an index cation such as Na+, removal of the excess salts of the index cation with a dilute solution, and then displacing the Na+ with another cation.
	The amount of Na+ displaced is then measured and the CEC is calculated.

11. Anion Exchange and Adsorption

	Anion exchange arises from the protonation of hydroxyl groups on the edges of silicate clays and on the surfaces of metal oxide clays.
	Anion exchange is inversely related with pH is greatest in soils dominated by the sesquioxides.
	The anions Cl-, NO3-, and SeO42- and to some extent HS- ands SO42-, HCO3-, and CO3- adsorb mainly by ion exchange.
	Borate, phosphate and carboxylate adsorb principally by specific adsorption mechanisms.

12. Metal Cation Adsorption

The relative affinity of a soil adsorbent to for a free metal cation with a given valence is positively correlated with the ionic radius.

Cs+ > Rb+ > K+ > Na+ > Li+ Ba2+ > Sr+ > Ca2+ > Mg2+ Hg2+ > Cd2+ > Zn2+

For transition metals the relative adsortion affinities does not conform strictly to ionic radius and tend to follow the following order:

Cu2+ > Ni2+ > CO2+ Fe2+ > Mn2+ Vocabulary

	Cation Exchange Capacity; - the sum total of exchangeable cations that a soil can absorb, expressed in centimolesc per kg of soil or colloid; http://jan.ucc.nau.edu/~doetqp-p/courses/env320/catexchange
	cation exchange - replacement by a cation in solution for an absorbed cation of negatively charged sites of a solid. http://jan.ucc.nau.edu/~doetqp-p/courses/env320/catexchange
	anion exchange - replacement by an anion in solution for an absorbed anion of positively charged sites of a solid. http://jan.ucc.nau.edu/~doetqp-p/courses/env320/anexchange
	percent base saturation - the degree to which the adsorption complex of a soil is saturated with basic cations (cations other than hydrogen and alluminum), usually expressed in percentage. http://jan.ucc.nau.edu/~doetqp-p/courses/env320/basesat

APPENDIX 2
A Review of Hands-on Agronomy, by Neal Kinsey, 1999, Acres U.S.A., Austin, TX.

1. BIODYNAMIC FARM MANAGEMENT – the Albrecht System.

http://www.acresusa.com/books/closeup.asp?action=search&prodid=5&catid=&pcid=2 (All references, unless otherwise indicated are to Hands-On Agronomy, by Neal Kinsey [http://www.kinseyag.com/ ] and Charles Walters, [http://www.acresusa.com/other/founder.htm ]Acres, U.S.A., P. O. Box 91299, Austin, TX 78709, (1999) . http://www.acresusa.com/magazines/magazine.htm

1. Testing. Testing is essential to keep the soil at its maximum production capacity. Soil conditions directly affect the plants, insect and weed issues. The micronutrients must be in a form which can be immediately used by the plants. The balance is important; just as important is the total amounts of nutrients. The soil test must both qualify and quantify the soil elements. P. 42 and generally throughout the text. Periodic tests must run, usually after each crop is harvested and at least annually. Crops, wind, water and tillage remove soil elements which must be replaced in order to achieve the proper balance.

2. Nutrient balance. An example of the nutrient mineral balance and replacement rate recommended for corn and cotton is:

	Range in soil	ESTIMATED CROP REMOVAL
Nutrient	(total lb/acre)	Corn (150 bu)	Cotton (1000 lb lint)
Boron	20-200	0.06	0.05
Copper	2 -400	0.05	0.03
Iron	10,000 – 200,000	0.10	0.07
Manganese	100 – 10,000	0.08	0.03
Molybdenum	1 – 7	0.03	0.02
Zinc	20.600	0.15	0.06

3. Clay and humus. Clay colloids are plate-like and lie on top of each other, forming a tight clay soil thus making it difficult for air and water to penetrate the layers. When humus is mixed, the fine clay particles adhere to the larger humus particles. Both particles are negatively charged and as such are easily separated by wind and water. Without positively charged particles, this clay/humus mix is easily eroded by wind and water. Pp. 30 – 42

4. Cation exchange capacity. A detailed analysis is done to determine the cation exchange capacity of the soil and is measured in milliequivalents. The CEC affects the colloid’s capacity to hold nutrients such as calcium, magnesium and ammonia nitrogen. A CEC of 10 in sandy soil will hold twice the poundage of nutrients than a CEC of 5. In a laboratory test, the CEC of the soil must be measured separately to determine the amount of calcium, magnesium, potassium and sodium it can hold. Pp. 32 – 33.

5. Humus. Humus is a necessary part of the soil foodweb. However, it must be in balance. Too much humus can create copper deficiency problems. Peat and muck-type generally have cooper deficiencies. A soil with 4 – 5 % humus can hold double the amount of moisture than the 1.5% to 2% can hold. Humus below 2% keeps the microbes on a starvation diet. P. 60.

Organic matter incorporated into the humus releases nutrients slowly over the growing season, increases water infiltration and the passage of air. A good balance of humus accelerates the growth of microbial elements which contribute to plant health and growth. It helps breakdown insoluble minerals and increases the base cation exchange rate. P. 61. The soil’s buffering capacity. “Farmers who have high organic matter or humus content soil can make many more mistakes without paying for them immediately.” P. 61.
The dark color of the humus favors heat absorption and permits early spring planting. Certain components promote growth-inducing effects. The humus is productive not only a greater microbial population but also one of greater diversity which in turn contribute to plant fertility. Humus has also been known to reduce the toxic effect of excess zinc and copper in Florida citrus groves. The water holding capacity of humus increases the efficiency of microbial decomposition of plant and animal waste. P. 62. Excess moisture can “work” the humus back to the starting point, thus making the soil compacted or sticky. Working wet soils annihilates the air and water spaces and removes the air needed by microbes. P. 63

6. Carbon to Nitrogen ratio. A carbon to nitrogen ratio of 10.4 to 1 is needed to build humus. If there is not enough air, the microbes will not multiply and the quantity of humus will not be made or simply evaporate. P. 64

7. pH balance. The pH measurement is one of several metrics to be applied to good soil balance. A “good” pH level does not necessarily insure a good soil balance. As an example a pH level of 7 on the water test might give assurance that the calcium level is correct, but ignores that the magnesium level is too high. P. 64. pH level is influenced by four major cations: calcium, magnesium, potassium and sodium. “Magnesium, pound for pound, can raise pH up to 1.67 times a high as calcium. A soil high in magnesium and low in calcium can test above 6.5 and still be inadequate to grow alfalfa.” Pp. 64-65.

“Causes of increased soil acidity: Development from acid parent materials. Plant removal of basic cations such as calcium and magnesium. Leaching of basic cation by rainfall Nitrogen fixation by bacteria on legume roots. Bacterial conversion of nitrogen compounds in the soil, including some nitrogen fertilizers.” Pg. 144.

8. Desirable versus tolerable pH. Slides by The Fertilizer Institute depicting “desirable” pH ranges are somewhat incorrect. “It really should be tolerable. Blueberries are shown to tolerate a pH between 5 and 6, but the best blueberries grow in the 6 to 6.5 range, provided all of the required nutrients are present in the property amounts.” P. 65.

9. Silica. Some crops require silica; watermelons for example require silica. They concentrate silica which is one reason they do well in sand. P. 66. It has been found to aid the crop in resisting mold penetration. Silica is necessary for animal diet and is found in shells of brown rice, in leafy greens and bell peppers. Processed foods mostly strip the silica from plant feedstock. “This massive loss of natural silica has been paralleled by an increase in degenerative diseases.” Klaus Kaufman, Silica, 1990, P. 67.

10. Calcium. Calcium is essential to feed the soil foodweb and plants. A 60% to 70% saturation of the clay colloids and soil water is required. A calcium deficiency shows up as a high acidity and makes it possible for manganese, aluminum and iron to become toxic. Pp. 73-74. Calcium activates several enzyme systems and improves microbial activity. Dolomitic limestone is the best source since it often carries with it needed magnesium. It also increases the availability of phosphorus and molybdenum Pp. 74 – 75.

Excess calcium can tie-up magnesium, potassium, boron, zinc and copper. Such excess may help in greater nitrogen access but with the result in weak stalks. Cooper is essential to stalk strength. Also, the higher the calcium, the easier it is for moisture to leave the plant. P. 79.
Different labs use different measurements to determine the levels of calcium; they have different numbering systems. One lab will report a 68% and a different one, 80% and the samples were the same. P. 80.

11. Magnesium. Magnesium helps hold the soil; it is the “sticky” part of the soil. If the soil is too dry and not sticky, it will erode as find dust. “Sticky” soil will clump or aggregate, thus binding the dust particles so they do not erode and also allowing for interstitial space for air and water. The “boot test” is if the soil sticks to the bottom of your boot in a thick layer. This is the equivalent of 30% base saturation of magnesium; it should be 12. Magnesium can raise pH by 1.67 as much as calcium. Magnesium as an ion has a ++ charge. The percentages of CEC are based on 60 – 70% calcium and 10 – 20% magnesium with a CEC of 6 or less. Pp. 84-85.

“Magnesium is found in minerals such as botite, dolomite and chlorite. Deficiencies occur most often in course textured, acid soils.” P. 85. “Magnesium in crop growth is: A mineral constitute of chlorophyll. Actively involved in photosynthesis. Aids in phosphate metabolism. Actives several enzyme systems.”
Pg. 89.
Balance is important. Soil is heavy and tight with a 90% calcium and 5% magnesium. The calcium is masking the true picture. By reducing calcium to 68%, one adds 22% to the magnesium availability.
“When calcium is driven out of the soil by too much nitrogen, magnesium remains unless sulfur is used to buffer the magnesium. Every time you put nitrogen on these soils, the total above 80 calcium-magnesium, the process takes the calcium down, magnesium up and magnesium is never going to be neutralized or taken out unless sulfur is used to complex the magnesium” Pg. 90.
Nitrogen overuse can affect the microbial breakdown of humus, especially the overuse of synthetic nitrogen.
“Nitrogen drives out calcium. When the soil is open and nitrites leach out and go with the water, it is never a solo journey. It always takes along a passenger. If there is a cache of sodium, nitrogen can take the sodium. Otherwise it takes calcium. Nitrogen never takes out the magnesium, but as nitrogen leaches downward, the passenger status of calcium is assured. …. For every percent of calcium taken out by nitrogen, magnesium goes up 1%. Removal of 10% calcium by nitrogen over-supply will increase the magnesium level by 10%. This is one reason nitrogen has a reputation for tightening the soils. Pp. 146-47.

12. Effect of calcium-magnesium ratio on air and water.

“Magnesium will never leave the soil, even if you pour on the sulfur or sulfates until calcium saturation is above 60%. One reason for this is that 60% or higher calcium gets the soil loose enough to permit the movement of the water. Without water movement through the soil, sulfur simply accumulates. As a consequence, before we would even try to take magnesium out of this typical sample, we would correct the calcium at leas to 60%. Based on the total exchange capacity of this soil, it would take two tons of calcium limestone per acre to correct the situation. Enough lime to bring the calcium up to 68% means an increase of 15%. Our objective is to bring magnesium down by 25% for a 68/15 position. The calcium reaction will bake here years because calcium breaks down about one third per year unless an extreme fine grind material is available.” P. 93. The author recommends as the lowest price amendment, Sul-Po-Mg or K-Mag. P. 93.

13. Calcium and magnesium levels and tillage. Kinsey recommends that after the amendment has been spread, that the soil be ripped by a shank ripper to break up the hardpan or plowpan. It is better to rip once a year for three years than make three passes in one year. Running the tractor over newly ripped soil will recompact the soil.

A soil probe should be used to take samples of the soil and the feel the resistance as the probe goes into the soil down four or five inches. The soil to five inches should be crumbly. Pg. 94. Deeper penetration tests can be used: Use a one half inch steel rod and a three pound mallet. The soil should have good penetration to 20 to 24” by allowing the weight of the mallet to drive the rod. P. 96
The key to yields is to get the root zone down as far as it can go. Where water can travel, so can roots. Soybean roots have been known to penetrate six feet. P. 100.

14. Nitrogen. Nitrogen, along with the other essential minerals and trace minerals are necessary for the soil foodweb and plant life. As with all of the soil contents, it must be in balance. Nitrogen deficiency in plants is found to examination. The leaf tip will begin to die off and move downward and inward in a V shape. In a potassium deficiency, the edges of the leaf will begin to die off. P. 106.

In an excellent situation 70% of the nitrogen comes from the microbes. Organic nitrogen in the form of organic matter, makes up 97 to 98% of the nitrogen in the soil, and is not generally available to the plants. Ammonium nitrogen, NH4, is held by soil colloids. Less than 1% of total soil nitrogen is in a form available to plants. Although some plants derive considerable amounts of nitrogen from the air (alfalfa -70%), the soil has the laboring oar for most plants. Microbes, such as Rhizobium genus of bacteria, supply the nitrogen in useable form. P. 100.
As an example, 150 bushel corn grown on a high magnesium soil would require 200 pounds of nitrogen per acre. In soil with a humus rating of 5.1, 100 pounds of nitrogen will be available. With a reading of 2.3, only 66 pounds of nitrogen will be available. The difference would be the required nitrogen from other sources. P. 111.
Nitrogen from manure is in ammonia form which easily goes from nitrite to nitrate form, which is volatile. P 124.

15. Effect of anhydrous ammonia.

“It is a fact that free ammonia is toxic to living organisms. When you knife in anhydrous ammonia into the soil, you are injecting free ammonia, and you are going to burn out some of the organisms. If anhydrous is applied in only a six-inch band, the assumption is that it can populate back. This is true. Just the same, the more you spread free ammonia, the harder it is on microbes. Also the reaction of ammonia with soil moisture produces ammonium hydroxide, which raises the pH. A raised pH has an effect on microbes. The most beneficial soil fungi, for instance, do not like a high pH. I fact, many can’t survive in such an environment, and so they die. Later, the conversion of ammonia to nitrate is accompanied by a production of acid, which lowers pH. Now bacteria have problems.”
“Anhydrous ammonia is NH3. The ammonia that attaches to the soil colloid is NH4. NH3 is ammonia gas. The NH4 is ammonia which is already stabilized. When urea goes from urea to ammonia, it goes from urea to NH3 ammonia gas and then to nitrite. This becomes the observed result because microbes convert it to a gas, after which it goes from nitrite to nitrate. Urea will hold, of course, if there is at least a half inch of water – rain or irrigation. Otherwise, the material must be applied and incorporated into the soil.” P. 150.

16. Phosphorus. Phosphorus promotes cell division, growth, photosynthesis and for energy transfer from ADP to ATP. It is absorbed into the plants as orthophosphate ions. Phosphorus will combine with hydrogen as either H2PO4 (-) or HPO4 (-2). The cheapest agricultural form is triple superphosphate. It is a plant feeder not a soil feeder and will revert back in one or two months to tricalcium phosphate which a plant cannot use except a legume. Some reserve in the soil is needed and should be mixed into the top six inches of soil.

Phosphate levels vary with changes in aeration, compaction, moisture, pH, and zinc. Soil with excessive zinc content will not produce crops or the yield will be less. Where zinc is excessive, and the weather gets cool, the plants cannot pickup phosphates well and thus the ADP to ATP conversion slows or stops. A soil pH of 6.5 will have available phosphates. Phosphates have to be replace which are taken up by crops. For instance a 180 bushel corn crop needs a 100 pound replacement. The most common application is concentrated or triple-superphosphate of 0-46-0. P. 158.
Rock phosphate is another source:
“For example, by treating 1400 pounds of a 33% phosphate material with 1200 pounds of sulfuric acid, a 20% superphosphate fertilizer is produced in which the tricalcium phosphate from of phosphorus in the rock phosphate is converted to the water-soluble monocalcium phosphate form. Such chemical reaction causes 20% superphosphate to be represented by approximately 45% of monocalcium phosphate and 55% of calcium sulfate (gypsum).” P. 160.
“Triple-superphosphate has a pH of 4.4 and when put into the soil, it starts combing with calcium, ‘like a southern is drawn to black-eyed peas’.” P. 164.

17. Soft rock phosphate. Hard rock phosphate at 6.5 is beyond ability of microbes to dissolve. Soft rock phosphate or colloidal phosphate is an alternative. 250 pounds of diammonium phosphate or 500 pounds of soft rock phosphate will both raise the soil phosphate levels by 100 pounds. P. 170.

18. Phosphorus and animal bloat. A field study indicated cows fed clover with a deficiency in phosphorus tended to bloat, while those fed clover with 300+ in phosphates did not bloat. P. 172.

19. Testing for phosphorus.

“Automatically, when you send a soil test to me, I tell the lab that I will pay extra expense. If it is above 7.5 [pH], I want a second phosphate test, namely the Olsen test. Relying on the Olsen test, if your calcium is correct and your other levels are there, 80 pounds per acre is enough. If you have 120 pounds, it is enough to matter what. When I say 300 pounds per acre is the minimum needed, the subject is water-solubles plus acid-solubles. And this is the minimum. I like to see phosphate levels in the 500 to 750 range. At 500 pounds per acre, I say excellent. When I see 750 or more, problems are coming down the pike on the other side. When phosphorus gets too high, it starts tying up copper and zinc.” P. 174.

20. Phosphate and boron. Phosphate deficiency will be exhibited in corn by a reddish-purple cast to the plants. Phosphate shortage will also interfere with pollination adversely affecting kernel fill and can also cause ears to be small and twisted. If at 400 pounds of phosphate per acre, the kernels did not fill, then the problem would be a boron deficiency. A corn farmer used four pounds of borate per acre despite the advice from the University of Illinois that two pounds per acre of boron would kill the corn. The farmer stated that the boron made the ears longer, but in reality, the kernels filled to the very tip of the cob. The message was, don’t let the lack of kernel fill mislead you into applying more phosphate since it could be a boron deficiency. P. 175.

21. Potassium. In soils with a pH of 6.5 and above, potassium will not do much in building the nutrient value of the soil. With high pH, potassium rarely can find a hydrogen bond, then push it out of the way attach itself to the base. In turn the calcium ion has twice the charge of potassium and easily displaces it. P. 180. By adding compost, potassium can begin building if the soil has a CEC of 7, 8 or 9 +. Potassium facilitates photosynthesis, transport and storage of carbohydrates, helps gets reserves into the roots for winter hardiness and is the foundation for cell development, cell wall construction and therefore stalk lodging. P. 181.

Total nutrient tests the total amount of potassium and other minerals. The question then is how much is available to be released? CEC tests will aid in this determination. Some universities recommend the application of 350 to 400 pounds in the top seven inches per acre. Yet farmers who follow this advice with soil above 6.5 pH are gaining very little potassium. Tight soil (too much magnesium) further complicates the availability of potassium. Until the concentration of magnesium is reduced, the colloid particles will not allow water to travel to the clay to make more sites for the potassium to attach. The higher the CEC, the more potassium is required. A CEC of 7 or higher, the pH has to be lower than 6.5 for the potassium ions to bind. Also, the higher the nitrogen, the more potassium input it will take to raise the level of available potassium. P. 184.
“In the presence of ammonium nitrogen, there will be a problem with microbial fixation and attachment to the soil colloids. The higher the nitrogen, the more potassium it will take to do the same job.” P. 185.

22. Potassium and sodium balance. When the saturation of sodium is higher than potassium, the plant takes the sodium to incorporate in to cell walls. In cool areas nothing happens, but in warm, humid climates, the sodium expands and breaks the cell walls which slowly kills the plant. In beans and peas this effect shows up as nematodes, but it is not. By building the potassium levels higher than sodium, the problem is solved. P. 189.

23. Potassium and weeds. When base saturation of potassium exceeds 7.5%, weeds proliferate.

24. Excess potassium and bitterness. Too much manure can raise the levels of potassium and cause bitterness in plant fruits. Additions of high calcium lime will solve the problem. As an example a dairy used a 40 acre pasture as its exclusive cow grazing area. Over time the cow manure increased the levels of potassium, causing the fodder to become bitter. The cows ate it because it was the only grass around. When the cow’s potassium-sodium level exceeds the calcium-magnesium level the cow dies a sudden death. If the imbalance causes cows to die, what is the effect on plants? Pp. 191.

25. Organic matter. According to William A. Albrecht, when you put manure on and work it into the soil, you stimulate microbial activity which in turn creates weak organic acids which break down the soil minerals. Manures seldom increases calcium in the soil, except for layer chicken litter because the chickens are fed oyster shells or other sources of calcium for thicker egg shells. Pp. 202 – 203. Continuous application of manure or compost will often result in copper or zinc deficiency. Cumulative applications can also cause the pH to drop as calcium is leached out of the soil. At the same time phosphate and potassium levels will rise, increasing the bitterness of the plants. Pp. 204- 205.

26. Compost. Compost piles go through a series of stages. Actinomycetes and streptomycetes first work the pile and easily digest the sugars present. These and other organisms create a mesophilic condition which raises the temperature above 100o F. Thereafter themophilic organisms generate temperatures up to 150o F. This fermentation destroys pathogens, seeds, animal carcasses and high carbon plant fibers. The resulting compost “banks” the nutrients and prevent the rapid leaching away of N, P and K. Pp. 206-207. Hog manures are effective in building phosphates. See generally, Fletcher Sims, P. 211.

Composting crop residue demands different handling. The carbon to nitrogen ratio of corn stalks or wheat stubble is 30 to1. This ratio must be reduced to 10 to 1 before humus can be built. Dairy manure mixed with straw will deliver a carbon to nitrogen ratio of about 28 to one. Spreading dairy manure could lead to weed growth because the potassium level is above 7.5% of base saturation. P. 209. Horse manure breaks down quickly but has a carbon-nitrogen ratio f 32 to 1, but you get calcium with horse manure. One gets more potassium from sheep and poultry manure. Overuse of layer manure, with its extra calcium, can tie up other needed nutrients. P. 210.
When manures are used, care must be taken and its properties considered by testing. Nitrogen conversion produces acidity and, without concurrent application of limestone, the effect will be the same as too much ammonium nitrate fertilizers.
“Consider the chemistry. Two ammonia and three oxygen ions convert to two nitrate nitrogen and six hydrogen ions. The six hydrogen ions contribute to acidity. …. When nitrogen is applied and the nitrate leaves, it doesn’t depart by itself. It takes along calcium or sodium or potassium or other cations present, magnesium being excepted. Taking away these cations and their replacement with hydrogen is a recipe for increased acidity in the soil.” P. 212.
Mycorrhizal fungi grow into or between the cells of the roots and use 10% of the carbohydrates. The plant passes the carbohydrates to the fungi in exchange for nutrients which the plant cannot itself manufacture. A plant colonized with mycorrhizal fungi will have ten times more roots than one without. Beck, Malcolm, The Secret Life of Compost, Acres, U.S.A., Austin, TX (1997); http://www.garden-ville.com/Books/Secret_Life_of_Compost.htm. P. 22. [Note: All reference in the balance of this sub-paragraph are to the above source unless otherwise note.]
Dr. Don Crawford, University of Idaho, developed a saprophytic, rhizophere-colonizing actinmycete, which attacks cotton root rot, a pest common to cotton, okra and similar plants. P. 23-24.
Microbes produce carbon dioxide gas in the root zone which filters up to the plant above, thus providing a rich source of carbon to the plant. The bigger and fast the plant grows, the more prolific are the microbes which in turn increases the carbon dioxide production just when the plant needs it. Pp. 40 -41.
Bare soil in the full sun was tested and found to be 35 degrees hotter (in Texas) than composted soil under plants. P. 41.
Earthworms dig into the sub-strata and bring the soil up to the higher strata. Worm castings have been found to be five times as rich in nitrogen, twice as rich in calcium and magnesium, seven times as rich in phosphorus, eleven times as rich in potassium. Earthworm tunnels allow air and water to quickly penetrate the soil and allow carbon dioxide and methane to escape. Beneficial soil organisms increase by seven times while harmful microbes and nematodes are destroyed as they pass through the digestion system of the worm.
Worms need organic matter to live. Worm fertility is directly connected to the level of food and moisture. Pp. 52 -53.

27. Herbicide infected compost: The herbicide, kTkordon-101 K, containing picloram and 2, 4 D, used to control broadleaf weeds, has become a matter of concern for the composting industry. This herbicide passes through the gut of cows and can have very negative impacts on sensitive plants if incorporated in compost placed on or near the plant. These and other herbicides are potentially injurious to strawberry, blueberry, balsam fir. The source is generally grass and hay used in cattle feeding and the resulting manure. David Bezdicek, Herbicide Contaminated Compost, Washington State University, http://www.compost.wsu.edu/content/clopyralid2001.html.

28. Sulfur. Sulfate as an ion is a major plant nutrient; humus is a major source of plant sulfur. The proportions of sulfur and humus are correlative. Humus stores sulfur. A heavy use of nitrogen will destroy the humus and soil sulfur. Plants take up sulfur; as an example, a 180 bushel yield of grain sorghum will take up 34 pounds of sulfur. P. 225. Adequate sulfur is necessary to make plant protein, chlorophyll, enzymes and vitamins. P. 221. Sulfur also improves the palatability of the crop. “All fruits are vastly improved in taste and keeping quality when sulfur is applied, and the nutrient also improves palatability of grasses and animal feeds. Sulfur increases the protein content and cancels nitrate content to a marked extent.” P. 227.

Kinsey recommends ammonium sulfate, doper sulfate, iron sulfate, gypsum, magnesium sulfate, Sul-Po-Mag where, after testing, these minerals are indicated. P. 227. Sulfur is mobile; phosphates are not. Sulfates, being water soluble, move around with the water and would recommend 200 pounds per acre if the soil is weak in sulfur. Sulfur dust and liquid sulfur can be applied to plants for insect control. P. 228.

29. Complexed/Chelated.

“The essence of this situation is that the minerals are tied into the enzyme by special bonds – call coordinate bonds – and when so bound, the entire molecule takes on new properties. Soluble forms of minerals may become insoluble, and vice versa; color changes may follow; speeds of action of a mineral salt may be multiplied a thousand fold, and mineral elements, which otherwise cannot enter a cell, may participate readily in intracellular activity when the metal becomes partly or completely surrounded by the organic portion of the enzyme. A partial surrounding of the mineral with the organic part of the enzyme is called, ‘complexed’, whereas a completely surrounded mineral is said to be ‘chelated’.
....[I]t is vital to ask ‘whether the body can absorb and utilize the complexed and chelated forms of minerals more readily than the inorganic forms.’ Logically, the answer is that the complexing and chelating remove the positive charge from the metals as they become dissociated in the stomach or intestine ... thus permitting the neutral or slightly negative complexed molecule to slide through the pores of the intestinal wall.” William A. Albrecht, private papers, Acres, U.S.A. collection. Pp. 222 - 223.

30. Trace elements as micronutrients.
    
    1. Zinc. Zinc acts as a catalyst; for instance in nut crops, which are zinc sensitive, a zinc deficiency will hurt the crop. P. 240-41. Common sources of zinc are:

SOURCE	ZN PERCENT
Zinc sulfates (hydrated)	23-35
Zinc oxide	78
Basic zinc sulfate	55
Zinc carbonate	52
Zinc sulfide	67
Zinc frits	Variable
Zinc phosphate	51
Zinc chelates	9-14
Other organics	5-10

31. Examples of what is found in typical mid-west soils:
    
    1. Boron: Range is 20 t0 200 pounds per acre (x 6”)
    2. Copper: 2 – 400 pounds
    3. Iron: 20,000 to 200,000 pounds
    4. Manganese: 100 – 10,000 pounds
    5. Molybdenum: 1 – 7 pounds
    6. Zinc: 2 – 600 pounds. P. 242

32. Plant uptake. Typical plant uptake for 150 bushels of corn, is: Manganese=0.08; molybdenum = 0.03; zinc = 0.15. Total soil content and uptake are a ratio. Kinsey states that you should have 300 pounds of phosphate for 150 bushel corn, but that it will take-up only 85 pounds. P. 243.

33. Limiting reactions: In chemistry we learned to predict and find the limiting element in a chemical reaction, then, by removing the spectator ions, we could derive the net chemical reaction. We could find how much of one atom or molecule was needed to completely react with a given quantity and type of another reactant. Kinsey discusses generally the limiting factors, but not in chemical formula terms. The discussion at pages 243 through 257 is about limiting reactions. The subject of limiting chemical reactions and plant health is beyond the scope of this paper, but earmarked here for further study.

2. Conclusion: For purposes of this paper, one concludes that success in biodynamic farming is to have the soil tested a laboratory which is setup to perform the correct tests – mineral content and percentages, pH and microbial content. An expert agronomist then can recommend the kind and quantities of additives, how they should be added and when they should be added in relation to the intended crop. The agronomist will also recommend means of keeping beneficial insects thriving, means of weed control, harmful insect control and control of pathogens. Neal Kinsey is one such expert.

END NOTES
1. Style Guide for Citing Electronic Documents:
Reference: Grassian, Esther. Thinking Critically about World Wide Web Resources [Online]. UCLA College Library: September 6, 2000. Available: http://www.library.ucla.edu/libraries/college/help/critical/index.htm. (May 23, 2001). Morris, Charles S. Citing Electronic Documents [Online]. http://www.lawrence.edu/library/guides/ecites.html. (Oct. 25, 1999).

2. Style Guide for Bibiographies and Footnotes:

Journal Articles: Reference: Watanabe K, Harayama S. 1998. Rapid estimation of population densities of uncultured bacteria in the environment. Microb Environ 13:123-127 Citation: (Watanabe and Harayama 1998)
University of Washington, University Library. 1999. CBE Style Guide. [Online] http://www.lib.washington.edu/help/guides/42CBE.pdf

2. Style Guide for Citing Biology Articles:

Article in a Scholarly Journal Holmberg S, Osterholm M, Sanger K, Cohen M. Drug-resistant salmonella from animals fed antimicrobials. New England Journal of Medicine 1987; 311: 617-622. Council of Biology Editors. Scientific Style and Format: The CBE Manual for Authors, Editors, and Publishers. 6th ed. Cambridge, England: Council of Biology Editors and the Cambridge University Press, 1994.
Ref. T 11 .S386 1994