1. Soils and Plant Nutrition Master Gardener Class

2. I can’t get any respect. People treat me like dirt!
What is Soil?
I can’t get any respect. People treat me like dirt!
Soil
Soil is the medium in which plants grow - the basis for plant growth.
Soil means many things to different people. For example, to a mom it is something that constantly needs to be cleaned. To a dad it is something to clean from under your fingernails with your pocket knife during a boring meeting. To kids it is something to play with and in.
To a gardener the soil is the medium in which plants grow. When problems occur start with the soil and work your way up. Better yet avoid problems in the first place by getting your soil in shape for optimum plant growth.
The goal of this module is to teach you about your soil, what it is, what your plants need, how to determine what you’ve got, and how to fix it.

3. Four Major Components of Soil
Sand
Silt
Clay
Air
20-30%
Mineral
45-48%
The mineral fraction is composed of three separates known as sand, silt and clay. The relative proportion of these separates is known as the texture of the soil.
Water
20-30%
Organic Matter
2-5%

4. Soil Components Sand = 2.0 to 0.05mm Silt = 0.05 to 0.002mm Mineral
Clay = less than 0.002mm
Mineral
The texture and structure of your soil are important because they influence the amount of air and water available to plants.
Imagine if you will a bin full of balls at the toy store. If it is full of big beach balls this would be like sandy soil, golf balls would be like silt, and marbles would be like clay.

5. The beach balls would have lots of large air pockets, and if you poured a bucket of water into the bin the water would drain very quickly to the bottom.
The golf balls would have smaller air pockets and the water would drain more slowly.
The marbles would drain much slower.
Knowing the texture of your soil will help you know how often and how much water your plants will need. How long to water and so on.

6. The proportion of sand, silt and clay determine a soil’s texture.

7. Soil texture determines a soil’s water-holding capacity

8. Relationship Between Soil Texture and Water Availability

9. Five Things Organic Matter Does for Soil:
Improves the soil’s physical condition.
Supplies plant nutrients.
Increases water infiltration.
Helps decrease erosion.
Improves soil tilth (the soil’s ability to resist compaction).
••• Basically nature’s way of recycling!
Organic
Matter
ORGANIC MATTER - ORGANIC MATTER - ORGANIC MATTER

10. The Ideal Soil for Crop Production
Medium texture and organic matter for air and water movement
Sufficient clay to hold soil moisture reserves
Deep, permeable subsoil with adequate fertility levels
Environment for roots to go deep for moisture and nutrients

11. Soil Depth Influences Relative Productivity
Soil depth usable Relative
by roots, ft. productivity, %
1 35
2 60
3 75
4 85
5 95
6 100

12. Soil Slope Affects Relative Productivity
slope, % Not easily eroded Easily eroded

13. The smallest particles of soil are called colloids
The smallest particles of soil are called colloids. Colloids have a negative charge so they attract positively charged particles. Colloids repel other negatively charged particles - like a magnet.
An element or group of elements with an electrical charge is called an ion. Ions with negative charges are called anions. Ions with positive charges are called cations.

15. Unlike a magnet, colloids can only hold a limited number of cations
Unlike a magnet, colloids can only hold a limited number of cations. The total amount of exchangeable cations a soil can hold (the amount of its negative charge) is called its Cation Exchange Capacity or CEC.
Soil Colloid K+
Potassium H+
Hydrogen 2
Ca +
Calcium
Mg +
Magnesium

16. Cation Exchange Capacity

17. 16 Nutrient elements are essential for plant growth and reproduction.
Plant Nutrients
16 Nutrient elements are essential for plant growth and reproduction.
16 plant nutrients have proven to be essential for the growth and reproduction of plants. They are needed in various amounts, but all are necessary.

18. Plant Nutrients C HOPKN’S CaFe Mg B Mn Cu Zn Mo Cl
See Hopkin’s Cafe Managed By My Cousin Mo Clay
The mnemonic above (Using the chemical symbols from the periodic chart) is a handy way to remember the nutrients.
C H O – Carbon, Hydrogen Oxygen
P K N – Phosphorus, Potassium, and Nitrogen
S- Sulfur
Ca Fe – Calcium and Iron
Mg – Magnesium
B – Boron
Mn – Manganese
Cu – Copper
Zn – Zinc
Mo – Molybdenum (isn’t that fun to say?)
Cl – Chlorine

19. Carbon - Hydrogen - Oxygen
The three most abundant elements - plants obtain them from water and air.
These three elements make up more than 94% of plant dry tissue. The remaining 13 elements make up less than 6% of plant dry tissue.

20. Macronutrients Micronutrients Nitrogen Phosphorus Potassium Sulfur
Calcium
Magnesium
Manganese
Iron
Boron
Zinc
Copper
Molybdenum
Chlorine
Macronutrients are those required in the largest quantity. They are further subdivided by primary (N, P, and K), and secondary (S, Ca, and Mg).
Micronutrients are required in very small quantities and are sometimes referred to as minor or trace elements.
Each of these nutrients has a job to do within the plant. Knowing what each does can sometimes help with the diagnosis of plant problems related to nutrient deficiencies. We will be discussing the role of each of these.
Do not fall into the trap that terms like major, minor, secondary, primary, micro, macro, and trace – fool you into thinking that some elements are more important than other nutrients. These terms merely refer to the relative amounts that are needed. They are ALL needed just in different amounts.
Micronutrients

21. Roots contact only a small percentage of available nutrients

22. Nitrogen . . . (N) A nitrogen deficiency most limits plant growth.
Provides a visual green response in plants.
Plants use large amounts of nitrogen.
Necessary for the production and transfer of energy - photosynthesis.
Stimulates plant growth.
Increases seed and fruit yield.
Improves the quality of leaf and forage crops.
Present in the soil in three forms.
Lets look at what the individual nutrients do in plants, and what plants may look like with different limiting factors. Obviously, there is much more that can be said about each of these elements, but this brief overview should give you an appreciation for the importance of each of these nutrients.

23. Nitrogen is present in the soil in three major forms:
Organic
Inorganic
Elemental
Organic nitrogen makes up about 5% of the soil’s organic matter by weight and about 98% of the total soil nitrogen. It is in the form of amino acids and other complex molecules. This type of nitrogen is unavailable (i.e. not in the right form) to be used by plants.
The organisms we talked about in organic matter, however, convert this type of nitrogen into the usable inorganic molecules. For this reason organic sources of nitrogen, such as manures, sewage sludge are “slow release” Once again the importance of healthy organic matter comes into play. I hope you are beginning to see that all of this fits together.
Inorganic forms of nitrogen include ammonium (NH4+), Nitrate (N03-), and Urea (CO(NH2)2).
Although ammonium can be taken up by plants when it is present in solution, plants most commonly take up nitrogen in the nitrate form. Once again ammonium and Urea are converted by micro-organisms in the soil.
Elemental nitrogen N2 is found as a gas in the atmosphere and this form is not used by plants.

24. (commercial fertilizers)
The Nitrogen Cycle
Atmospheric
nitrogen
Atmospheric
fixation
and deposition
Industrial fixation
(commercial fertilizers)
Crop
harvest
Animal
manures
and biosolids
Volatilization
Plant
residues
Runoff and
erosion
Biological
fixation by
legume plants
Plant
uptake
Denitrification
Organic
nitrogen
Nitrate
(NO3)
Ammonium
(NH4) -
Immobilization +
Leaching
Mineralization
Component
Loss from soil
Input to soil

25. Nitrogen Deficiency
Nitrogen deficiencies appear as a general yellowing of the leaf, frequently starting at the tips of the leaves. If the condition persists necrosis (tissue death) and leaf drop may occur. The entire plant may be stunted in it’s growth.
Nitrogen moves quickly through the soil profile and the levels can change very quickly. For this reason a soil analysis does not report the nitrogen level unless specifically requested. Nitrogen deficiency is one of the most commonly encountered nutrient deficiencies.

26. Phosphorus . . . (P) Also an essential part of photosynthesis.
Responsible for utilization of starch and sugar.
Cell nucleus formation.
Cell division and multiplication.
Cell organization.
Transfer of heredity.
Photosynthesis is the conversion of carbon dioxide and water in the presence of light to sugar and oxygen. ATP play a large role in the conversion of this stored energy into a useful form. Without going into too much detail ATP stands for Adenosine Triphosphate. The phosphate part is a form of phosphorus.

27. Phosphorus Cycle

28. Phosphorus Deficiency
A phosphorus deficiency appears to have deep blue-green or red-purple coloration. Plants may have poor flower, fruit, and seed development, slow and stunted growth.

29. Potassium (K)
After nitrogen, plants use the largest amount of potassium.
Plays an essential role in the metabolic process of plants.
Plays a role in raising the disease resistance of many plant species.
Potassium is supplied to plants as a cation (remember from earlier that is a positively charged ion). This becomes important in light of our earlier discussion concerning the CEC of your soil. Soils with a low CEC and rainfall or irrigation are likely to see potassium leached quickly.

30. How Potassium Moves in Soil

31. Potassium Deficiency
Potassium deficiencies appear as interveinal chlorosis (yellowing between the veins of the leaf). If the condition persists the yellow areas may become necrotic. Other symptoms include leaf margins becoming brown and curled downward, small fruit or shriveled seeds, and slow growth.

32. Calcium (Ca)
An essential part of the wall structure and strength of plant cells.
Provides for normal transport and retention of other elements.
Does not move in plant, deficiency develops in new leaves
Counteracts the effects of alkali salts and organic acids within the plant.
Calcium: Young leaves are affected before older leaves and become distorted, small in size with spotted or necrotic (dead) areas. Bud development is inhibited and root tips may die back.
Tipburn on lettuce is a symptom of calcium deficiency but is also caused by other factors not associated with a solution deficiency.
Blossom end rot of tomatoes is also caused by a deficiency of calcium within the fruit tissue (not necessary in the nutrient solution), and is more of a `calcium transport' problem within the plant under certain environmental conditions.

33. Blossom end rot in tomatoes. Bitter Pit in Apple
Blossom end rot in tomatoes. Bitter Pit in Apple. Are disorders caused by a calcium deficiency.

34. Magnesium . . . (Mg) Is essential for photosynthesis.
Makes up a part of the chlorophyll in green plants.
Helps activate plant enzymes needed for plant growth.
Dolomitic lime and epsom salts contain Magnesium

35. Magnesium Deficiency
Symptoms of a magnesium deficiency is chlorosis between the veins of the leaves. As you may recall some other nutrient deficiencies are described in the same way and we will discuss this a little later in the program.

36. Sulfur . . . (S) Activates plant enzymes.
Is required for nodulation and nitrogen fixation of legumes.
Present in glycosides which give the characteristic odors and flavors of mustard, onion and garlic.
Sulfur is present primarily in the organic matter and becomes available upon their decomposition.
The primary form of sulfur used by plants is the soluble SO42- form
The use of gypsum (CaSO4) increases the sulfur in the soil.
Elemental sulfur is used to lower the pH. If your pH is too high do a soil test then call your County Extension Agent with the pH and the buffer pH to determine how much sulfur to add.

37. Soil organic matter is a major source of S

38. Symptom of sulfur deficiency is chlorosis between the veins
Symptom of sulfur deficiency is chlorosis between the veins. Again chlorosis between the veins – How might we tell the difference between each of these symptoms? Keep going to find out.

39. Manganese . . . (Mn) Iron . . . (Fe) Activates plant enzymes.
May substitute for magnesium
Iron (Fe)
Essential for the synthesis of chlorophyll.
Symptoms include chlorosis between the veins with green veins
Symptoms of a Manganese deficiency include: smallest veins green, interveinal chlorosis beginning at margins, progressing to midribs, followed by interveinal necrotic spots: No sharp difference between veins and interveinal areas as with iron deficiency. Manganese deficiency can be induced by high levels of iron.
Conversely, iron deficiencies frequently are induced by high levels of Manganese.
Iron is frequently sold in a chelated form that can be applied to plants. It is frequently helpful to “green-up” a plant without adding more nitrogen.

40. Sample of iron deficiency
Sample of iron deficiency. Notice the chlorosis between the veins, while the veins themselves remain green.

41. Copper . . . (Cu) Zinc . . . (Zn) Essential for plant growth.
Activates many plant enzymes.
Zinc (Zn)
A copper deficiency interferes with protein synthesis and causes a buildup of soluble nitrogen compounds. Excess copper can cause iron deficiency.
Symptoms of copper deficiency include: Terminal wilting, chlorosis, rosetting and death: veins lighter than inter-veinal areas
Symptoms of zinc deficiency include: very small stiff chlorotic or mottled leaves; decrease in stem length and shortened internodes causing rosetting.
Regulates plant growth by controlling the synthesis of indoleacetic acid.
Activates plant enzymes.

42. Boron . . . (B) Molybdenum . . . (Mo)
Regulates the metabolism of carbohydrates in plants.
Molybdenum (Mo)
Boron can occur in acid or alkaline soils, but is more common in alkaline soils. Symptoms of boron deficiency include: Death of terminal buds, later buds and root tips also die, or lateral growth has few leaves that are chlorotic or necrotic, small brittle, thick and cupped downward.
Symptoms of molybdenum deficiency include: a general chlorosis then interveinal chlorosis leaf margins may curl or roll then die; stunting and lack of vigor
Required in tiny amounts.

43. Micronutrients ARE NOT miracle workers

44. Nutrient Deficiencies
A note about nutrient deficiencies:
While many deficiencies show specific symptoms this is an inexact science at best.
Many of the symptoms overlap so the only way to be sure is with a combination of tissue analysis and soil sampling.
We will talk about soil sampling later in this program.
Tissue analysis is available through the plant problem clinic at Clemson University Cooperative Extension Service.
The following are recommendations regarding a tissue sample:
Do not sample pesticide, dust or soil contaminated tissues. If all the tissue available is dusty, wash gently in flowing , clean water
Do not sample tissue which is diseased or damaged by insects or machinery
Place the plant tissue sample directly into clean paper or cloth bag envelopes. If the plant tissue is wet or succulent, leave out in the air one day until wilted and partially dry. Do not put samples in plastic bags.
When sampling suspected nutrient-deficient plants, take two samples if possible – one from the normal plants and the other from abnormal plants.
When sampling, both the stage of growth and the plant part collected are important. Be sure to collect the proper plant part at the recommended stage of growth.
Sample leaves which are representative of the current season’s growth during the mid period of the growth cycle or just before seed set.
can be taken the the local county extension office

45. Nutrient Deficiency Symptoms
Position on plant
Chlorosis
Leaf margin necrosis?
Color and leaf shape N
All leaves
Yes No
Yellowing of leaves and leaf veins P
Older leaves
Purplish patches K
Yellow patches Mg Ca
Young leaves
Yellow leaves S
Mn, Fe
Interveinal chlorosis
B, Zn, Cu, Mo -
Deformed leaves

46. Soil pH is a measure of the hydrogen ion concentration in the soil.
Buffer pH is the soil’s ability to resist changes in pH.
pH effects a plants ability to utilize nutrients. For example, all of the necessary nutrients may be in the soil, but if the pH is too high or too low they will be unavailable to the plant.
Buffer pH is important because it is used to calculate the necessary ingredients to change the pH to the desired level. We may know that the pH is low – say a pH of We know we will want to add lime to raise the pH. You will need to know the Buffer pH to calculate the correct amount of lime to add.
Fortunately, if you do a soil analysis the computer does this for you – if you do the pH with a store bought tester it doesn’t tell you the buffer pH value so you still do not know how much to add to get to the desired level.

47. Optimum pH for most plants
pH Units
Neutral
Range of Alkalinity
Range of Acidity
A pH above 7 is alkaline
A pH below 7 is acid
A pH of 7 is neutral.
Most plant prefer a pH between 5.5 and Some plants are tolerant above and below this range and may be useful in conditions outside of this range.
Most, but not all, soils in SC are in the acid range and lime is necessary to bring the pH to the desired level.
It is also interesting to not that many plants that are sold as acid loving (azaleas, camellias) actually prefer a pH of 5.5 to Acid yes, but still within the optimum range. For many soils lime is still necessary to grow these plants at their optimum level in SC. Only a soil test can tell you for sure what you need for these crops.
Two plants that are truly acid loving are blueberries and potatoes – they are usually grown at a pH of 4.5
Optimum pH for most plants
5.5 to 6.5

48. This chart shows the availability of plant nutrients at different pH levels. The wider the bar the “more available” the plant nutrient.
Draw a line from bottom to top and find the pH with the thickest lines.
For example at a pH of 4.5 (not uncommon here in SC) iron, manganese and boron are taken up pretty well, but the other nutrients are nearly completely unavailable. They may be in the soil, but the plant cannot use them – Remember CEC and all the stuff?
You will find that the optimum availability occurs around pH 6.5

49. Factors in Addition to Soil pH Which Influence the Frequency of Liming
Soil texture
Rate of N fertilization
Rate of crop removal of Ca and Mg
Amount of lime applied
pH range desired
Tillage system
Irrigated crops

50. Why Acid Soils Should Be Limed
Increases CEC in variable charge soils
Increases availability of several nutrients
Supplies Ca and Mg to plants
Improves symbiotic N fixation in legumes
Improve crop yields
Reduces Al and other metal toxicities
Improves the physical condition of the soil
Stimulates microbial activity in the soil

51. Soil Acidity Affects Plant Growth
Aluminum, Fe and Mn can reach toxic levels because of increased solubilities in acid soils
Reduced activity of organisms responsible for the breakdown (mineralization) of organic matter
Possible Ca deficiency but most likely a Mg deficiency

52. Soil Acidity Affects Plant Growth
The performance of soil-applied herbicides can be adversely affected
Reduced activity of symbiotic N fixing bacteria
Clay soils high in acidity are less highly aggregated
Availability of nutrients such as P, K and Mo is reduced
Tendency for K to leach is increased

53. How Lime Reduces Soil Acidity
Ca2+ ions from aglime replace Al3+ at the exchange sites. The Al3+ reacts with water releasing H+…
Carbonate ions (CO32-) from aglime react in the soil solution, creating excess OH- (hydroxyl) ions which combine with H+ ions forming water
The pH increases because the acidity source (H+) has been reduced
(Al3+ + H2O Al(OH2+) + H+

54. Liming Materials Calcitic Lime Dolomitic Lime Hydrated Lime Wood Ashes
(Use 75% of the above recommended amount)
Wood Ashes
(Use with caution!)
You’ve done a soil test, and found out your pH was low and you need to add lime. You will find there are a number of materials available. The most common, and recommended, is Dolomitic lime. Dolomitic lime contains magnesium as well so it helps with that nutrient too.
Dolomitic lime comes both pelletized and crushed. Pelletized is easier to spread, but takes longer to take effect than does crushed.
Lime can be put out at anytime of the year, but is best when done in the late fall. That way it can do it’s thing before the growing season, and you do not risk burning plants in the summer heat.
Some people interested in organic solutions use wood ashes to adjust the pH. The main caution here is that the pH of wood ashes can vary considerably and are difficult to get consistent results. You may raise the pH too much if you are not careful. They also act rather slowly so be careful if you choose this option.

55. Relative Neutralizing Values of Some Common Liming Materials
Liming neutralizing
material value, %
Relative
Liming neutralizing
material value*, %
Calcium carbonate 100
Dolomitic lime
Calcitic lime
Baked oyster shells 80-90
Marl 50-90
Burned lime
Burned oyster shells
Hydrated lime
Basic slag 50-70
Wood ashes 40-80
Gypsum None
By-products Variable
*Relative neutralizing value is used interchangeably here with calcium carbonate equivalent

56. Particle Size Determines Lime Reactivity
in 1 to 3 years, %
Lime reacted
Finer particle size
(logarithmic scale of mesh size)

57. For best results, apply lime well ahead of planting to allow sufficient time to neutralize soil acidity

58. Fertilizer grade (or analysis) refers to how much of an element there is in a fertilizer based on percentage by weight.
Fertilizer ratio describes the relative proportions of N-P-K in a fertilizer.
The analysis or grade is part of the label on the fertilizer bag. It tells you how much of which element and which forms of those elements (you know the ones we just discussed?) are in each bag. The analysis is regulated by the state to be within certain limits of the analysis on the bag.
The fertilizer ratio are the three numbers on every bag of fertilizer, such as or This is the ratio of N-P-K or Nitrogen-Phosphorus-Potassium. Remember that the numbers represent compounds not just the elements. Without going into the math this means that a 100 bag of of may contain less than 30 lbs of N-P-K elements. The rest are fillers, and conditioners. These numbers become important because frequently recommendations for home lawns are given in lbs/1000 ft2, but we will get into that in a couple more slides.
First, let’s introduce some other terms that pertain to fertilizers.

59. Fertilizer is referred to as:
Complete when it contains all three major plant nutrients.
Incomplete when it lacks one of the major plant nutrients.
Balanced when it contains equal amounts of N-P-K.
Premium refers to fertilizers that contain the minor elements
Slow release refers to fertilizers that release the elements slowly over time
Be aware of these terms they sometimes are used in soil analyses or by vendors. There are times when each may be appropriate for your needs.
would be an example of a complete fertilizer because it has all three elements.
would be incomplete because it contains only N
would be a balanced fertilizer because it has all three elements in the same ratio. It doesn’t imply a balanced (better) diet.
Premium fertilizers are usually worth the few extra dollars because they do contain the minor elements and you will not usually have to worry about deficiencies with these elements if you are using a premium fertilizer. If you do have a deficiency the use of a premium will likely solve the deficiency
Slow release fertilizers come in at least two common forms: Those that release with temperature, and those that release with water. The first type is more expensive, but releases the fertilizer at the appropriate temperature for the plant to be able to use the nutrients. Slow release fertilizers, of any type, are usually a worthwhile investment as they are less likely to cause chemical burn and they are available to the plant for a longer period of time. If, however, you are dealing with a deficiency you may want to choose “normal” quick release fertilizers as they will be available to the plants much quicker.

60. Let’s Do Some MATH
Many fertilizer recommendation come as pounds of (insert element) per 1000 square feet.
If you add that much product you will NOT get the right amount because the product contains only a percentage of the element.
So now what do you do?
Ok so here is the problem - To determine the amount of ammonium sulfate a 5,000-sq ft lawn needs if the lawn requires one lb of nitrogen per 1,000 sq ft...
Ammonium Sulfate is so only 21 percent is nitrogen. That means that in a 100 lb bag there are approximately 21 lbs of nitrogen Here the next slide explains it . . .

61. To determine the amount of ammonium sulfate a 5,000-sq ft lawn needs if the lawn requires one lb of nitrogen per 1,000 sq ft...
Lawn: 5,000 sq. ft.
Fertilizer: Ammonium sulfate (21-0-0)
Rate of Application: 1lb of nitrogen per 1,000 sq. ft.
Ammonium sulfate is 21% nitrogen.
21% is the same as 0.21 or 21/100.
This means for every 100 lb. of fertilizer there are 21 lb. of nitrogen.
We need 1 lb of nitrogen for every 1,000 sq. ft. Using proportions, we can calculate the amount of ammonium sulfate needed to get 1 lb of N. “X” represents the unknown amount being calculated.
AHHHHHHH, this is too hard to do and even harder to explain. Let me show you my cheaters method.
21 lb. N
100 lb =
1 lb. N
X lb

62. Tim’s Method ½ lb/1000 ft2 = 50 1 lb/1000 ft2 = 100
To get the right amount of product take the constant supplied on the right and divide by the analysis of the element you want.
½ lb/1000 ft2 = 50
1 lb/1000 ft2 = 100
1.5 lb/1000 ft2 = 150
2 lb/1000 ft2 = 200
2.5 lb/1000 ft2 = 250
See the pattern?
For the example to apply 1 lb of nitrogen /1000 ft2 using /21 = 4.76 lbs of per 1000 ft2.
As my high school algebra teacher told me don’t ask me why just do what I tell you! For this problem if you needed to do a 5000 ft2 yard I would multiple the answer (4.76) times 5 to get the total amount of fertilizer I would need for the yard (23.8 or 24 lbs of ).
Some other numbers that my come in handy for your – 43,560 ft2 equals one acre, therefore you can “guesstimate” a quarter acre to be 10,000 ft2, one half acre to be 20,000 ft2 and three fourth acre to be 30,000 square feet.
So if you are applying 1 lb of Nitrogen per 1000 square feet to your quarter acre lot with ammonium nitrate, you will use approximately a 50 lb bag – right?

63. How much lime and fertilizer should I add to my garden?
O.K. now you know about pH, Essential Nutrients, Fertilizers, CEC, Organic Fertilizer – so let’s put all this together into something useful.
How much of each of these should I add to MY soil for MY plants to get them to grow to be “the best they can be?”. Lawn, garden, whatever, the answer is the same and FINALLY,The answer is on the next slide!

64. Soil Test Soil Test Soil Test Soil Test Soil Test
Finally, we are ready to talk about the Soil Test – as if I haven’t been saying it throughout the whole program!

65. Soil testing is essential to applying the correct fertilizer and Lime!
Adding fertilizer to the soil without testing is like baking a cake without reading the recipe or measuring the ingredients
Can I say it any louder? SOIL TEST – SOIL TEST – SOIL TEST
There probably is not a better horticultural deal on the market than a soil test.
First lets talk about taking a good sample, then we will talk about the analysis that comes back and what it all means.

66. The greatest potential for error in soil testing is in taking the sample

67. A good sample is critical to getting a good soil analysis!
The results of a soil analysis are only as good as the sample that is used for the analysis.
A soil sample consists of 12 –20 subsamples (the more the better) from a given area. Each subsample can be taken by the methods illustrated above, from the surface of the soil to about 6 inches deep. The subsamples are combined and mixed well. A two cup sample from this can be brought to the office for analysis. The lab needs a minimum of two cups to analyze the soil. I usually recommend that you bring 3 or more cups to allow for settling etc. . .
You should do separate sample for each area that is treated differently or where the soil is different. For example I have an area of my yard that is mostly sand and another area that is mostly clay. I take different samples for each of these areas.
When you bring your sample to the office you can give up to four different crops for each sample. When you get the report back it will give you recommendations for all four crops separately.

68. Sampling for Home Gardens and Lawns
Consider different soils and management situations that need to be sampled

69. When you get a report back this is what it will look like
When you get a report back this is what it will look like. This particular report had four crops: Warm-Season Grass Maint., Carpetgrass, Centipedegrass, and Azalea, Rhododendron, Camellia. In the top left hand corner circled in red is the soil pH and Buffer pH (remember the optimum pH is 5.5 –6.5 for most plants, and the buffer pH is the soils resistance to change). Because the report does the calculations for you, you can forget these numbers. The amount of lime required is circled in red at the bottom right.
Remember an acre consists of 43,560 square feet, therefore if this person had a quarter acre lot they would need about 410 lbs of lime, half acre 820 lbs of lime, ¾ acre 1230 lbs of lime, and one acre about 1640 lbs of lime. How did I get these numbers?
I rounded the 43,560 to 40,000. Then divided by 4 to get the area for a quarter acre (10,000 ft sq). If I have 41 lbs/1000 ft sq and multiply by 10 I get 410 for 10,000 ft sq. And you thought you wouldn’t have to do word problems ever again. At least it isn’t two trains leaving from separate stations . . .
For most homeowners the bar graph, nutrients, and the other numbers can largely be ignored. They are used for calculating the comments section for farmers and specialty crops.
Under each crop a number of comments are listed. The comments are found on page two of the report which we will discuss in the next slide. You will notice some of the numbers apply to more than one crop.

70. The comments are pretty much self explanatory they tell you what fertilizers to use, when to use it, and how much to use. You match the crop on the previous page with the comments on this page.
In this case the warm season grass recommendations are circled in yellow and the azalea, rhododendron, camellia recommendations are circled in blue – Notice different amounts and types of fertilizer are used for the different crops.

71. Plant analysis and soil testing go hand-in-hand

72. Soil Testing vs. Plant Analysis
Soil testing and plant analysis are complementary, but very different …
Soil tests predict nutrient availability
Plant analysis assesses nutrient uptake
Soil tests are not always good predictors of nutrients that leach easily, i.e. N or S
Plant analysis is a better tool to assess some micronutrients, e.g. B, Fe, Mo

73. Let’s Review To a horticulturist what is soil?
What is organic matter and what does it do for the soil?
What is pH? What is buffer pH?
How can I KNOW how much lime and fertilizer to add?

74. Other Recommended Information Follow the Links
Bob Lippert’s Soil Page
Indoor plants
Fertilizing Lawns
Mulch
Fertilizing Trees
Fertilizing Vegetables
Home and Garden Information Center (HGIC)
Soil testing
Changing the pH of your soil
Fertilizers
Composting

75.
On the left you will see a link to the South Carolina Master Gardener Program.
This program is available under both powerpoint presentations and Electronic Training

76. Credits
I am not a soil scientist so much of this was taken from several sources. Some of the following are sources I’ve “stolen” this information from. Thanks to all who had a part.
South Carolina Master Gardener Manual
Home and Garden Information Center (
Bob Lippert’s Powerpoint (Clemson University) Slide Presentation
Michelle Clark’s (Richland County Master Gardener) MG Slide Presentation
Brian Smith’s (Charleston County Extension Agent) COTS Slide Presentation

77. This concludes our lesson.
If you have questions feel free to me at
This course has only skimmed the surface of what there is to know about soils and I have included some links to other information about soils on the next slide.
Remember all plants start in the soil so when there are problems start with the soil and work your way up. Chances are “fixing” the soil may fix your problem.