The soil is a dynamic body, teeming with microorganisms whose activities vary from day to day and from season to season with changes in temperature, moisture, and food supply.
Soil is the material on the earth’s surface that can support the roots of plants and provide nutrients for plant life. Plants are dependent on water, the sun, and the soil’s nutrients to give them energy for vegetative growth and reproduction. The health, vitality, and yield of the plants are directly related to the nutrient content of the soil in which they are grown.
The condition of our soils is important because all life on earth is dependent on soil. A close look at healthy soil reveals that it is teeming with life and activity. It is rich in organic matter, insects, earthworms, air, water, and nutrients. Healthy soil retains nutrients and has a texture that allows water and air to permeate it. The four major components of soil are mineral matter, organic matter, water, and air. The mineral matter such as stones and rock powders usually originates from the bedrock that lies beneath the soil. Organic matter (humus) is the decayed remains and waste products of plants and animals.
Healthy soil must be fertile and for soil to be fertile, it must have nutrients readily available and a pH value at a recommended level for the plants that will be grown in it. The pH level of the soil refers to its acidity or alkalinity and each plant has it own preferred value range. Soil pH is one of the most important soil properties that affect the availability of nutrients. In the desired pH range of 6.5 to 7.5, nutrients are more readily available to plants and microbial populations in the soil increase.
It is important to note that the mineral composition of the soil is what makes the difference between rich fertile soil and poor infertile soil. Plants need minerals to be in an available and balanced form. Minerals are what create sweetness, flavor, and nutrition in fruits, grains, and vegetables. Without balanced minerals, it is possible to achieve high production, but not the highest quality nutritional food.
Nutrition brings genetic potential.
History of Soil and Nutrition in the USA
In the western movement of farmers to the American frontier, the search was always for good fertile land. Virgin soils were the most continuous attraction drawing people to the wilderness in the west. Those pioneers who were the most successful in finding the best soil actually felt, smelled, and tasted it before putting down stakes.
Year by year the farmers lived on the soil and eventually discovered that their unrotated crops diminished their returns. They had not replenished the soil nutrients their crops had used up. With the offer of virgin soil farther west at nominal prices, many farmers moved on after a few years. Unfortunately the economics favored using up the nutrients in the soil without replacing them. They had not learned the lesson that soils are dynamic. They were not committed to maintaining soil fertility by encouraging soil life and replacing the nutrients and minerals their crops had used.
Today in America sustainable farmers and growers are very aware of the importance of building healthy, balanced, nutrient-dense soil for their present use and also for succeeding growers. They know that the health of their soil correlates directly with the mineral density of the crops and produce they harvest. They also know there is a strong connection between soil, food, dinner plate, and human health. Healthy soil results in healthy food and healthy food results in healthy humans.
There is a link between soil quality and nutritional decline. Unfortunately, from 1940 to 1991, the produce quality in the United States has dropped. The USDA confirms this loss of nutrients. On the average, fruit lost 60% of its mineral density and vegetables lost nearly 80%.
We need to work hard at reversing this trend of declining nutrition in our foods and make sure that we grow nutritious, wholesome foods. The number one goal for growers must be the production of top quality herbs, fruits, and vegetables that are full of nutrients and vitality and taste delicious. The largest sphere of influence with which to raise the quality of our current produce is the soil. In the end, we must garden and farm from the bottom up. The beginning of great gardens and produce acres that produce healthy, nutrient-dense produce is the soil.
The road back to healthy soil includes managing residue and seeding cover crops, both done in the fall after harvest. Residue management is an excellent way to incorporate nutrients back into the soil. This involves chopping or shredding the stalks of the previous season’s plants immediately after harvesting them. These stalks have pulled many minerals out of the soil to nourish the plants. Minerals, nitrogen, sugars, protein, and saps are left in the stalks and it is beneficial to return them to the soil.
Digestion in the soil is as important as digestion in the human body. Just as human bodies need enzymes to break down food, so the soil needs microbes to break down the corn stalks, vines, and other plants that were growing in gardens. The residue needs to be turned back into the soil because it contains nutrients for next year’s crop.
Use a good microbial package such as Lancaster Ag’s d-Compose for fall application and distribute across residue and entire garden to aid digestion in the soil. A bacteria product, like d-Compose that contains enzymes, will break down the residue. Shallow incorporate the plant residue and d-Compose into the soil by tilling no more than 6-inches deep. There are several tillage methods that work well.
Seeding a cover crop before putting a garden to bed for the winter adds many benefits to the soil. After incorporating the residue, seed a cover crop such as Jerry Forage Oats. The cover crop’s roots will hold the nutrients that were just applied. It is a way to feed soil by providing readily available nutrients when residue goes into the soil, thus adding nitrogen and organic matter. Plus, a cover crop also prevents wind, water, and soil erosion during the winter months.
In the spring, inoculate cover crops with d-Compose. Then turn under the cover crops well ahead of planting time. The nutrition in cover crops is now available in the soil for spring plants.
Minerals in the soil need to be plentiful, available, balanced, and diverse.
Minerals are as essential to healthy soils and plants as air is to young infants when they begin to breathe. No one would think of closing off an infant’s airway, but that is in essence what we are doing by not applying minerals to our soils.
Minerals are important for beneficial bacteria to flourish in the soil, fungi to form, algae to develop, plant root exudates to grow, and roots to elongate. All of these are needed for increased plant resistance to stresses from disease, insects and weeds, and an increased ability of the plants to efficiently use soil water.
Plants have a marvelous immune system, similar to a human’s immune system. When that immune system is supplied with resources such as minerals, it will combat diseases and ward off insects. Thus, it is possible to control insects and diseases with nutrition instead of relying on fungicides and insecticides.
A focus on disease and insect prevention through nutrition requires a balance of trace minerals. It is important to plan for ways to get trace minerals back into the soil because plants that have trace minerals applied along with their general fertilizer program, will have better health and more sustainability. A major benefit will be higher quality grains, fruits, and vegetables with more potency and pungency.
The lack of trace minerals in soils will definitely have an adverse effect on plants. They will be starving for these nutrients if trace minerals are not put in the soils every year to feed the soil biology. Soil nutrient deficiencies need to be addressed so that this trend can be reversed. Feeding soil life with full nutrition and a broad spectrum of trace minerals is the place to start.
Trace minerals determine the quality of the plants grown and that has an ongoing domino effect on humans who consume the plants. These minerals are very vital for humans to survive, function, and enjoy good health. Thus, to improve human health, our soils need to be improved with trace minerals.
Here is a listing of soil nutrients and minerals that will improve our soils and preserve this rich natural resource for future generations. The following entries that describe soil nutrients will help us on our sustainable journey to a greener tomorrow.
The three essential nutrients in soil for proper plant growth are nitrogen (leaf growth), phosphorus (root growth) and potassium (overall health). Plants use large amounts of these primary nutrients for growth and survival. These nutrients must be replaced in order to maintain the proper soil conditions for ongoing plant production.
Helps plants with rapid growth, increases seed and fruit production, and improves the quality of leaf and forage crops
Affects rapid growth, encourages root growth and blooming, aids in proper plant maturation, helps plants withstand stress, and is vital for mineral absorption and sugar production
Helps photosynthesis, aids in the building of protein, affects fruit quantity, reduces diseases, and determines size and bulking
We are awed by the complexity of the many elements needed in the soil for good healthy life to exist at that level.
It is interesting to note that all of these elements are supplied through the natural system in amounts that are adequate and balanced.
When we neglect the natural system, deplete the soil or add detrimental ingredients, we upset the balance of nature and create a domino effect of problems that begins in our soils and consequently extends to our plants and eventually to our own human health.
Also important in soil are these secondary nutrients; calcium, magnesium and sulfur. Large amounts of calcium and magnesium are added when limestone and rock powders are applied to acidic soils. Sulfur is produced by the microbial life in the soil in a form that plants can use. The slow decomposition of soil organic matter helps to keep the proper amount of sulfur in the soil.
An essential part of plant cell wall structure; provides for normal transport and retention of other elements; gives strength to the plant,; counteracts the effect of alkali salts and organic acids in the plant; and along with phosphorus, is the nutrient that is the most important for farmers to apply to soil for quantity and quality of plants
Essential for photosynthesis, activates many plant enzymes needed for growth, and is an essential mineral to be added to forage crops for optimum animal herd health in many ways
Produces protein, improves root growth and seed production, aids in chlorophyll formation, promotes development and activity of enzymes and vitamins, helps with vigorous plant growth and resistance to cold, and is vital in the digestive tract in livestock production
In all there are 40 minerals that plants need for proper, healthy growth. Many of these are needed in only very small quantities. We call these trace minerals. Many are abundantly available in the soil, but they need the action of microbes to make them usable by the plants. The following are five of the most essential trace minerals in the soil.
Essential for seed and fruit development, helps in the use of nutrients such as in calcium uptake in the tissues, regulates other nutrients, aids in the production of sugar and carbohydrates, required so that calcium can perform its metabolic chore.
Important for reproductive growth, key to elasticity in the plant, controls mold, interacts with iron and manganese
Draws energy to the plant leaf by absorbing heat from the sun; essential for the formation, maintenance, and synthesis of chlorophyll and RNA metabolism in the chloroplasts
Breaks down carbohydrates; aids in nitrogen metabolism; is synergistic with iron; brings the electrical charge into the seed, creating the magnetic force to draw the other elements into the seed
Regulates plant growth and consumption of sugars, essential for the transformation of carbohydrates, contributes to test weight, helps to make acetic acid in the root to prevent rotting
We have been aware of the importance of microbes in our life since the Germ Theory of Disease, based on the findings of Louis Pasteur and other scientists. Now we recognize the idea that one certain bacteria causes us to get a cold is naïve. The etiology of disease is much more complex than that. Two men may be exposed to the same bacteria, but only one will be affected, perhaps because of a weakened immune system or other factors.
Microbes affect us much more for good than they do for ill. We need them in our bodies to aid digestion and in our soils to make nutrients available for plants. “Whether in our bodies or in the soil,” writes Paul W. Kaiser, “microbes demand a complete meal. They reject cheap, adulterated foods and fertilizers. N-P-K (Nitrogen-Phosphorus-Potassium) chemical fertilization of our soils causes biological problems.” We want to keep our microbes healthy and happy by supplying them with the minerals they need in a readily available form and by avoiding the use of harsh chemicals. Here at Lancaster Ag we follow this principle in developing our soil treatments and foliar sprays.
Microbes are also essential in the composting process. By inoculating the materials we compost with an assortment of microbes and by checking moisture levels and other conditions often, we can substantially add to the value of the organic matter being composted. Our Fall Dry Blends use this type of beneficial compost.
Note: If conditions are not controlled properly, the resulting compost can do more damage than good to our soils. For example, this is the case with mushroom soil.
Another way we help our soil is by inoculating the soil in the autumn with strains of microbes that are known to be of benefit. Our Bio-D and D-Compose will boost the levels of different microbes and will supply them with foods that they need to flourish. This can be supplied directly as a liquid treatment to the soil or it can be applied as part of the mix in our Dry Blends.
Carbon is a non-metal element that occurs in all organic life and is the basis of organic chemistry. It is a basic element of our life-sustaining universe.
Carbon is contained in all proteins, sugars, starches and other carbohydrates. Without carbon, there would be no fats, oils, vitamins, amino acids, enzymes or hormones. Some of these compounds are very basic to the life cycles and functions of plants, animals and people. Carbon is so linked to all of life’s processes that life cannot exist without it. It has the interesting chemical property of being able to bond to itself as well as to a wide variety of other elements, forming almost 10 million known compounds. Some of these compounds give flavor to many fruits.
Calcium is the king of nutrients. It has the responsibility of moving the soil’s nutrients into the plant.
It must be present in sufficient quantities in the soil so that plants receive the proper quantities of calcium, phosphorus and all other nutrients. Calcium levels at 70-75% of the soil exchange capacity indicate proper amounts of calcium are present. This will improve the root system, the stem and the leaves of the plants. Proper levels of calcium improve soil texture (flocculation) by causing the soil particles to be loosely bonded to each other, rather than sticking closely to one another. Soil that is properly flocculated allows more air and water to enter the soil structure. When air and water enter the soil structure, they provide the soil structure with oxygen and nitrogen as well as other nutrients. A proper level of calcium provides an environment that is conducive to the life of soil microorganisms.
In most plants, calcium deficiency is first observed in the roots of the plant. When calcium is deficient, the root growth is reduced and root rotting is noticed before there are symptoms expressed by the vegetative part of the plant. When calcium deficiencies are severe, growing points are distorted, look spotted, fail to grow, and even die.
Livestock with effective calcium levels will exhibit some or all of the following characteristics: better bone and tooth formation, improved nerve function, effective muscle contraction, better blood coagulation, and increased cell permeability. Calcium is essential for milk production and for formation of eggshells in poultry.
Calcium is very important to animal life. It is a large factor in proper bone and tooth formation and proper skeletal growth. Calcium somewhat regulates cell permeability, meaning adequate calcium must be present to cause nutrients to be able to enter into the cell, thus providing for proper cell development. As a result, this function gives proper nerve function, muscle contraction, and blood coagulation. The calcium content of milk shows the importance of calcium for milk production in mammals. Inadequate calcium in animal diets will cause general unthriftiness in mild cases or serious illness in extreme situations. Calcium regulates proper eggshell and skeletal formation in poultry.
Magnesium should occupy 10-20% of the soil’s exchange capacity.
It is a key element in photosynthesis, because it resides at the heart of the pigment that contains molecular chlorophyll. If photosynthesis declines, crop quality and yield will also decline. Magnesium is a constituent of chlorophyll, aids in phosphate metabolism, and activates several enzyme systems. Magnesium and calcium are the keys to proper air and water in the soil. Magnesium helps to hold the soil together and tighten it up.
Improper magnesium levels lead to poor crop growth. An effective solution is to apply magnesium sulfate. In contrast to low levels, excessive magnesium results in heavy tight soil, weeds, and low levels of nitrogen. This can be corrected by applying gypsum.
Magnesium in cattle is absolutely essential for normal skeletal development because it is an ingredient of bone material. It is an enzyme activator and helps to decrease tissue irritability & grass tetany.
Phosphorus is the catalyst of life.
A catalyst is something that must be present for the consumption of other things; however, the catalyst itself does not become completely used up in the process. All nutrients, with the exception of nitrogen and sometimes potassium, must be compounded with phosphorus to be provided to the plant. It is the job of phosphorus to compound all these nutrients, combining them with itself so that calcium can carry everything into the plant. Organic phosphates are the compounds that provide the energy for most of the chemical reactions that occur in living cells. Therefore, enriching soils with phosphate fertilizer enhances plant growth. Phosphorus contributes to root, flower, and fruit development.
Phosphorus is contained in all tissues and it is the workhorse of plant nutrition. It is responsible for cell division, cell growth, and photosynthesis. Phosphorus is used in a 1:1 ratio with potassium. Soil must have good phosphorus uptake to build good sugar levels in plants.
Low phosphorus levels retard soil life and contribute to low sugar levels in plants. It also results in poor quality produce because phosphorus is needed to move other nutrients in the plant. This condition can be corrected by applying soft rock phosphate. Colloidal sources of phosphorus will not leach out of the soil.
Phosphorus is integral in livestock bone and tooth formation. It is important for metabolism and cell membrane structure. Phosphorus is a component of RNA and DNA, is required for protein synthesis, and contributes to the metabolism of several enzyme systems.
Nitrogen is a governing factor in the decay of plant materials.
It is used to form chlorophyll, proteins, and amino acids and to stimulate growth. Ammoniacal nitrogen is the form of nitrogen used by a plant for reproduction. If sufficient ammoniacal nitrogen is not present, plant reproduction will be hindered. Every cell in plant life requires nitrogen.
If nitrogen levels are decreased adversely, soil reactions are slowed and there will be lower protein levels. The end results will be less growth and decreased quality. Low nitrogen can be corrected by applying compost, manure, fish, or by planting cover crops. Work with the soil biology to increase overall biology and boost the ecosystem of the soil.
Note: Over-applying nitrogen will result in excessive growth and will cause soil runoff into streams.
Nitrogen is a main constituent of animal tissue and flesh, along with carbon, hydrogen, and oxygen.
Complacency about potassium levels in the soil is dangerous.
Potassium is a catalyst in chlorophyll production; a governor for taking free nutrients from the air such as carbon, hydrogen, and oxygen; and is needed so that plants can make starches, sugars, proteins, vitamins, enzymes, and cellulose. Additionally, potassium is essential for protein synthesis and formation. Potassium improves the flavor and color of fruits and vegetables and promotes drought tolerance, winter hardiness, and disease and insect resistance. It contributes to stem and root growth and is necessary for the translocation of sugars, the proper color of fruit, and the bulk (size) of a crop.
Insufficient potassium results in negatives such as low energy for crops, lack of drought tolerance, smaller stalks, and lower yield.
In contrast, too much potassium from excessive manure application results in grassy weeds, reduced calcium uptake in plants, lower plant health and quality, and poor livestock health. This can be corrected with hi-calcium limestone.
In livestock potassium is a major cation (positively-charged element) of intracellular fluid and is required for muscle activity. It also aids in enzyme reactions involving creatine and influences carbohydrate metabolism.
Sulfur is a constituent of proteins and resembles oxygen, but is less active and more acidic.
It is essential for formation of sulfur-containing proteins and its release in the soil is governed by the size of the organic matter held in reserve.
Sulfur remains a key element in crop proteins. Sulfur is necessary for the formation of high-quality protein. It is a requirement for nitrogen fixation in legumes and is vital to vitamin synthesis in all plants. These two actions are important determinants of crop quality. Sulfur gives onions, garlic and mustard their distinctive flavors.
If sulfur levels are adversely low, plant proteins will be incomplete, humus will not form properly, and soils will have low energy. These conditions can be treated with gypsum or sulfate of potash-magnesia.
In livestock, sulfur helps to contain amino acids. It is a component of biotin, thiamin, and coenzyme and is important in lipid metabolism, carbohydrate metabolism, and energy metabolism.
In healthy soil boron provides translocation of sugar, regulates flowering and fruiting, and helps cell division, salt absorption, and calcium uptake.
It is necessary for hormone movement, pollen germination, carbohydrate metabolism, water use, and nitrogen assimilation in plants. Boron is a trace mineral that can leach depending on the soil biology. It is necessary for proper shaping of the fruit of plants, such as filling the tips of the ears of corn, and is needed in the building blocks of protein.
In livestock, boron functions in the synthesis of glycogen and the maintenance of body fat in animals.
Copper is vitally important to root metabolism and is essential for disease resistance and elasticity of cell walls.
It also helps to form compounds and proteins, amino acids, and many organic compounds. Copper provides the catalyst component in enzyme systems, helps produce dry matter via growth stimulation, and prevents development of chlorosis.
Copper is necessary for hemoglobin formation in livestock and is essential in enzyme systems. It assists in hair development and pigmentation, bone and collagen development, conception, sperm production, and ovulation. It is also necessary for lactation and normal growth.
Zinc is absolutely vital to the life processes of soil microorganisms. It aids in the promotion of normal growth, increases moisture uptake, and regulates plant sugar use.
Zinc is needed for bone, hair, and feather development and for normal protein and RNA synthesis. It is a factor in sperm production, reproduction, feed utilization, healing of wounds, vitamin A metabolism, hemoglobin production, and immune system function and metabolism.
Manganese plays a major role in photosynthesis and chlorophyll synthesis.
Carbohydrate metabolism and seed formation will not occur without it. Manganese accelerates seed germination, fruiting, and ripening of crops. It also assists in the assimilation of nitrates.
Livestock need manganese for normal bone formation and activation of enzyme systems. Manganese helps provide for amino acid and protein metabolism, fatty acid synthesis, and cholesterol metabolism. It is needed by the hormone and immune systems and is required for growth and reproduction.
Iron is an indispensable carrier of oxygen that is required in the production of chlorophyll.
It aids in the prevention of chlorosis and is necessary for immune system function and normal growth.
Iron is a constituent of hemoglobin, the iron-containing compound in the blood that transports oxygen. It plays a role in cellular oxidation, is a component of certain enzymes that are involved with oxygen transfer, and helps the immune system and normal growth.
An advantage of selenium is that it transfers easily from the soil to the plant. This makes application easy.
Selenium is an antioxidant along with vitamin E. It is involved in the absorption and retention of vitamin E and is essential to the immune system. Selenium is required for normal growth and for reproduction. It prevents degeneration and fibrosis of the pancreas in poultry.
Molybdenum is essential for plants, but only in trace amounts. It governs microorganisms that are needed to set the stage for anion nutrient uptake and assists nodulation in legumes.
Molybdenum is required for the conversion of nitrogen to protein.
Cobalt in the soil benefits soil microorganisms, is a precursor to enzymes, and is a biostimulant.
This means it is required by nitrogen-fixing bacteria, especially on the root nodules of legumes. Cobalt is needed for the synthesis of nutrient-dense feeds and foods. These nutrient-dense compounds are necessary to resist insect and disease attacks.
Cobalt is a component of vitamin B12. Rumen microorganisms use cobalt for the synthesis of vitamin B12 and the growth of rumen bacteria. Cobalt is needed for normal growth of the animal and healthy animal physiology. As in the soil, cobalt is a precursor to enzymes.
Chlorine is essential to growth in some plants.
In livestock, it is a major anion involved in osmotic pressure and acid base balance. Chlorine is a chief anion of gastric juice, where it unites with hydrogen ions to form hydrochloric acid.
Soil is the material on the earth’s surface that can support the roots of plants and provide nutrients for plant life. Plants are dependent on water, the sun and the soil’s nutrients to give them energy for vegetative growth and reproduction. The health, vitality and yield of the plants are directly related to the nutrient content of the soil in which they are grown.
The purpose of soil testing is to determine the nutrient density of the soil and the relation of the different nutrients to each other. A soil test is used as a road map for treatment of our soils. By reading this road map, we can understand where we presently are and gain a vision for what we need to do in the future. With regular soil testing and recordkeeping, we can see the changes and the nutrients that we used to bring about the changes. We recommend that soil samples be taken every two or three years. Under some circumstances, such as very poor fertility, the growing of high-value crops or severely out-of-balance soil, Lancaster Ag may recommend soil testing more frequently.
There are several things to consider when taking a soil test. These things include proper depth, representative sampling of the area, the time of year and how fields were previously sampled. The proper depth is important to give the correct pounds of nutrients per acre. Sample depth should be 5.25 inches. The cores of soil taken need to represent the area or field that is being sampled. To be able to compare this year’s sample to that of previous years, fields should be sampled in the same way every time. Fields should be sampled at the same time of year, preferably during July and August.
Our soil testing service provides us with information using Ammonium Acetate, Bray II, Water-Soluble and/or Soluble methods. The Ammonium Acetate and Bray II methods provide the standard measurements in pounds of calcium, magnesium, phosphorus and potassium in the soil. These numbers are compared to each other by mathematical calculations that provide the base saturation of the cations of the soil. The Soluble Test section near the top of the printed test results shows nutrient levels that are actually available to the root for plant nourishment. As the energy produced in the soil by the interaction of the nutrients of the soil becomes available, the root of the plant exchanges hydrogen for nutrients. The sun provides the energy for the whole process of plant growth. These tests are designed to give us the best possible understanding of our soils.
A soil test is a snapshot of the condition of your soil at a given time. When you look at test results, remember that the soil is a living, changing and dynamic entity. Many soil labs and firms that sell fertilizer reference soil testing as a precise science. They suggest that if you take enough samples, you can build exactly the right program to give you the maximum economic yield. It is correct that very sophisticated equipment exists to permit a lab to determine in parts-per-million the presence of various elements or compounds. Many growers who regularly use those soil tests apply the same program regardless of the soil test results. At the other extreme, some companies are now purchasing soil application equipment with on-board computers that automatically adjust the rate of flow of three or four separate fertilizers according to the soil test results. An important question to ask is, “How was the soil test number used to decide which elements to apply and how much of each?”
In other words, the real challenge is to interpret from a set of numbers on a paper what energy frequencies and levels will be available to the next plants to grow in that field. A further challenge is to predict the impact of warmer-than-normal temperatures, excess moisture or a lack of moisture on available energy.
Consult your Lancaster Ag representative for a complete soil nutrition program.
A soil test is important but only provides approximate information to answer these questions. A test for the levels of biological life and the species of biological life present in a soil would be very helpful as well. These tests are presently very expensive and time- consuming, thus they are not widely used.
Most commercial and university soil labs use a test that measures the holding capacity of a soil (the cation exchange capacity) and then determines how much nutrient is actually being held by the clay and humus colloids. This test uses several chemical solutions to extract elements from the soil being tested.
According to this theory, soil, clay and humus are negatively charged and will hold positively charged mineral nutrients. The higher the clay and humus content of the soil, the higher the CEC or greater the number of nutrients the soil can hold. The nutrients deemed to be present are the ones removed by the extract solution.
There are two limitations of this test. First, the abilities of the soil extract solution and the plant rootlet to remove the nutrient from soil colloids are probably not the same. Secondly, no consideration is given to the energy made available to the plant during the growing season by the soil biological system. For example, if a soil is biologically dead, much less energy will become available than in a well-mineralized, biologically alive soil. There is a tendency for this test to overestimate nutrient availability.
In summary, the cation exchange test is helpful if it is used as an approximate inventory of potential plant food. It might be regarded in the same way a mining company looks at a mining essay report.
We use the Morgan Soil Testing System, sometimes referred to as the LaMotte Test, in addition to CEC. test procedures. The distinctive feature of this test is the employment of a single extracting solution. It is a 10% solution of sodium acetate in 3% acetic acid and has a pH of 4.8. This provides a weakly ionized, organic acid buffered with its sodium salt.
In theory this should extract nutrients from the soil sample in a manner similar to that used by a plant rootlet. It is thought that the LaMotte Test gives a better approximation of nutrients actually available to the plant than the CEC. test.
The soil is a dynamic body, teeming with microorganisms whose activities vary from day to day and from season to season with changes in temperature, moisture and food supply. Nitrate and ammonia nitrogen contents of the soil are especially variable. A rapidly growing crop depletes the soil of its nutrients that are required for plant growth. There are also seasonal fluctuations in the soil acidity that influence the availability of plant nutrients to some extent. The degree of acidity is associated with the leaching of bases and production of nitrates. Acidity is normally at a minimum in early spring and a maximum in midsummer.
All of the above factors must be taken into consideration in the interpretation of the tests. For general soil diagnosis, tests on samples taken in early spring are most reliable. Soils studied during the growing season give test results closely related to the performance of the crop. These results are particularly valuable in determining immediate need for supplemental fertilization.
Tests in the autumn, after the crop is harvested, best indicate whether or not the fertilizer has been in excess of crop needs. Fall testing has the added advantage of allowing ample time in which to obtain materials and make plans for spring work. Choosing the time of the year when the sample is taken depends upon the purpose for which the test is conducted.
The following is an example of how the two tests can be used together to complement one another. If the CEC test shows a medium-to-high base saturation of calcium, but the LaMotte Test shows low available calcium levels, we will use biological products to enhance the soil bacterial action in the breaking down of any added lime, which then will make the calcium available.
When using a LaMotte Test, the soil test data should be considered with reference to the limiting effects on crop growth that may be expected from other factors.
Other factors can include poor aeration, a restricted root system caused by undesirable soil structure or soil tilth, deficient drainage, low organic matter content, unfavorable seasonal conditions, plant pests and plant disease. Irrespective of the chemical fertility of the soil, the crop expectation is less than normal when any or several of these factors are present.
If you are evaluating any soil test, balance is more important than building high readings. The highest yields with the lowest input costs come from balanced fields.
When using a CEC test to evaluate soil fertility, the following base saturation levels will indicate a well-balanced soil:
Nutrient Desired % Base Saturation
Calcium 70-80%
Magnesium 10-15%
Potassium 2-4%
Hydrogen 5-10%
Sodium 1- 1.5%
Dr. Carey Reams was a strong advocate of the LaMotte Soil Test. He recommended the following levels of soluble nutrients as being desirable, using the Morgan Testing System extract solution:
Soluble Calcium 2000-8000 lb./acre
Soluble Magnesium 285-1145 lb./acre
(We want a ratio of 7 parts calcium to 1 part magnesium.)
Soluble Phosphorus 100-200 lb./acre
(Our soil test report reads in pounds of phosphorus per acre, to convert to P205 and K20 values, not the straight soil test readings.)
Ammoniacal Nitrogen 40 lb. per acre
(This is nitrogen combined with hydrogen and is cationic in energy form.)
Nitrate Nitrogen 40 lb. per acre
(This is nitrogen combined with oxygen and is anionic in energy form.)
Nitrogen exists in the soil largely in the form of partially decomposed, organic residue that contains proteins. Microorganisms such as bacteria and fungi gradually transform this nitrogen into ammonia compounds. Organic nitrogenous fertilizer materials and legume crop residues are readily attacked due to their high protein content.
The chief reason the ammonia test fails to reveal more than small amounts present under normal field conditions is due to the rapid change of ammonia to nitrates by bacterial activity.
High tests for nitrate nitrogen in field soils are to be expected only when the root system of the crop is not yet fully developed.
High nitrogen test results indicate a large reserve of readily available nitrogen for the use of the crop. Rapidly growing annual crops require a large reserve during the period of most active growth. The gradual processes of nitrogen liberation are rarely sufficiently rapid to meet their requirements at the time. Crops with perennial root systems such as sod grasses, shrubs and trees take up nitrogen through a much longer period of the year, therefore low nitrate tests do not necessarily indicate a lack of available nitrogen.
Low tests are to be expected at the end of the cropping period, during winter and early spring and after a period of heavy rainfall. Under such conditions, when all other factors are favorable, the absence of nitrates may not necessarily indicate poor availability of soil nitrogen, but the crop is likely to respond to the addition of a readily available nitrogenous fertilizer.
An erg is a measure of soil energy release equal to grams/sec. Ergs are directly equal to conductivity units on the conductivity meter, micromhos/cm/sec. The ergs test will tell if there is enough energy reaction going on in the soil to grow a plant. It will change during the growing season. Ergs should be between 40 and 150 at planting time. If it is too low, it means there is not enough energy coming out of the ground to support the plant. This means a waste of energy and money. At pollination time, the ergs should reach the maximum needed. It should not be less than 100 or more than 400. It is best to keep an average around 200.
pH is usually considered a measurement of acid or alkaline properties, but it can also be used as a measure of resistance. Technically it is the negative logarithm of the hydrogen ion concentration. In practice a pH of 7 means that there is an equal resistance between anions and cations. pH does not indicate if calcium needs to be added to a fertility program; it only indicates frequencies. Ideal soil pH is from 6.5-6.8.
pNa is a measurement of the sodium ion activity level. This reading is taken to check for potential salt toxicity levels. It is best to have the pNa of a soil read between 2.6 and 3.0. Readings below 2.5 have sodium ion activity above the desirable level. A low reading means high salt.
In conclusion, the practical value of any soil test is limited chiefly by the qualifications of the person who is responsible for translating the data into amounts and kinds of fertilizers, manures, lime and other soil amendments or treatments that are most likely to be effective in promoting profitable crop production.
Obtain a soil test kit from your Lancaster Ag Representative or call us at 717-687-9222. Take a soil sample between July and September following the kit instructions. We recommend soil sampling your soil every two or three years and that each following sample is taken during the same month of the year. Send your soil sample to your Lancaster Ag Representative for testing and yearly product recommendation.
Please Note: All equipment must be clean
Choose various areas in the field that represent the soil in the whole field. Suggestion: 15 locations in a 20-acre field. Crop land and pasture land should be sampled separately.
Use a clean spade, auger, or soil probe. Stainless steel probes are available for purchase from Lancaster Ag at cost. Use a clean plastic bucket in which to place the samples.
Scrape away any surface residue. Bore down 5 inches with the probe and place sample into bucket or dig a 5-inch v-shaped hole with a spade. Cut a slice of soil making sure to include soil from top, middle, and bottom of hole. Place in bucket.
Thoroughly mix all of the samples together in the bucket.
Place 2 cups of soil in the soil sample bag provided, up to the line. Clearly print the following on the bag: full name, complete address (including house number and name of street or road), number of acres or square feet of area, name or number of sample.
Making a map of the locations in your fields where you obtained your samples is very helpful. Send one copy with the sample and keep one copy for your records.
Mail sample bag to Lancaster Ag Products, 60 N. Ronks Road, Ronks, PA 17572. After your sample reaches us, a copy of your results will be available in 7-10 days. Please contact us at 717-687-9222 to discuss recommendations. A copy of your results will be mailed to you and a copy will be kept on file at Lancaster Ag.
Please Note: Tissue samples are time-critical
Pull 20 leaves from a plant or tree. The type of information you want will determine the location on the plant or tree from where you will pull the leaves. Please be consistent.
Place leaves in bags that breathe, such as brown paper bags or bags that have holes, so that the samples start to air dry before they get to the lab. Ask your Lancaster Ag Representative for special bags for your tissue samples.
Write full name and complete address (including house number and street or road name) on the bag. Include a description of your fertilization practices up to this point.
Your Lancaster Ag Representative can deliver the samples after a farm visit, if schedules permit, or please ship them to Lancaster Ag. Please Note: Producers out of the local area need to use one-day shipping service.
Lancaster Ag processes the samples for analysis the same day they arrive in our office. These samples are timecritical.
Please Note: Forage samples are time-critical
Mail samples to Lancaster Ag Products, 60 North Ronks Road, Ronks, PA 17572 or bring samples to the Retail Store as soon as possible. Lancaster Ag will have your test results in approximately two days from the time we receive your sample.
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