Soil Analysis The Reasons And Hw Method

Soil Analysis - The Reasons

• Presented by Dallas Hanks

Acknowledgments

• Utah State Universtiy Extension Service

• Colorado State University Extension Service

• Ohio State University Extension Service

• University of Idaho Extension Service

• Cornell Cooperative Extension Service

• I have found that a great part of the information I have, was acquired by looking for something and finding something else on the way. Franklin P. Adams

Ultimate Soil Properties

AIR-(20-30%)

WATER (20-30%)

ORGANIC (1-6%)

MINERAL (45%)

AIRWATER

ORGANIC

MINERAL

Quality Soil Properties

Conventional Uses of Soil Analysis

• Increasing knowledge of what nutrients are specifically available in your soil

• Reducing environmental impacts due to soil amendments

• Increasing efficiency of resource inputs such as fertilizers and water

• prediction of nutritional values needed for crop production

How Often Do You Check Your Oil?

• Once every month at least??

• Why??

• To protect investment

• To ensure minium levels

• Prevent repairs that may be more costly

• Signal that a repair needs to be done

• Ensure envt. concerns

Soil Testing

• “A soil test is the best method to determine whether ... fertilizer is needed” (USU Extension Fact Sheet HG/H5)

• “The soil test is an excellent measure of soil fertility. It is a very inexpensive way of maintaining good plant health...”(OSU Extension Fact Sheet HYG-1132-97)

• “Quality topsoil is the basis for quality landscapes” (USU Extension Fact Sheet AG/SO-02)

Objectives of Soil Analysis

• Determine the status of soils I.E. nutrient availability

• Macro• Micro• Salt conditions• pH• Texture• Organic matter• Form a basis to determine fertilizer needs

Cautions about soil analysis

• Irrigation techniques and amounts

• Pest or toxic problems

• Poor soil structure and drainage

• Variety choice

• “HOME SOIL TEST KITS ARE OF LITTLE TO NO VALUE. They are designed for eastern soils and give very poor accuracy on our western soil types.”

Phases of Soil Analysis Progam

• Sampling

• Extraction and chemical analysis

• Interpretation and making recommendations

Soil Sampling

• The results of your soil test are no better than the sample you send to the lab.

• The sample must be representative of the area being considered.

• IF YOU DO NOT SAMPLE CORRECTLY YOU WILL NOT RECEIVE A RELIABLE DIAGNOSIS.

Tool for Soil SamplingShovel Probe Bucket

Taking a Soil Sample• 1. With a shovel, make a hole in the soil. SAMPLING DEPTH SHOULD BE

AS DEEP AS TILLAGE. Do not just sample the surface.– Shrubs, bedding plants and Trees - 0-12 inches– Turf - 3 inches

• 2. Throw this shovel full of soil aside. • 3. Cut a ½ to 1 inch slice of soil from the side of the hole. Be sure the slice

is fairly evenin width and thickness.• 4. Place the slice in a bucket.• 5. Repeat steps 1 through 4 at about six different locations. This step is

important to obtain a representative sample.• 6. Thoroughly mix the 6 sub-samples.• 7. Send about 1 pint of the thoroughly mixed garden soil for the test.

Obtaining the soil sample will be easier if you have a soil probe or bulb planter.

• 8. Supply the information on the test form for better interpretation of results.

Extraction and Chemical Analysis

• Extract “available” portion of the nutrient

• Measure the concentration of the extracted nutrient

• Extractant is the most important part of this procedure

Conventional Methods of Soil Analysis

• Nutrient extraction (hasn’t changed in some instances since 1940's)


• For each nutrient, mix soil with extracting reagent


• Shake each sample for respective time (30- 90 min)

Filter the sample

A New Way of Doing Things

• Often discovery is founded on a legacy• History of this project:• Turf nutritional recommendations• Increase in soil analysis (GPS)• Just a faster, easier, less expensive way

of doing things• Fuelky and Czinkota • Expense and labor of Soil Analysis

Proposed Soil Nutrient Extraction using Hot Water and Pressure

• nutrient extraction

• Simply allow HW method to extract and filter the sample (1-5 min)

• analyze using standard methods

• Chromotography

• Spectrophotometry

Reasons for HW

• Laboratory• decreased analysis time• less hazardous chemical disposal• Portability• On site anaylsis• Increased demand for soil analysis • Precision Agriculture• G.P.S.

Materials and Methods

• Use an Braun T-250 espresso machine for equipment

• generated 2.5 bar and temp of 93 C

• 5 gram soil

• 100 ml of distilled water

• 2 mm filter paper

Cont.

• Allow water to heat to constant temp

• Make extractionm vent closed

• Switch from steam to cup

• Allow all water to pass through sample

• Avg time - 1.4 min

Numbers of Samples??

Results and Discussion

0

50

100

150

200

250

HW

Nit

rate

pp

m

0 20 40 60 80 100 120 140 160

Standard Method Nitrate ppm

N

Nitrogenr2 = 0.98, p = 0.001

0

50

100

150

200

HW

meth

od

0 10 20 30 40

Standard method ppm

Sulfater2 = 0.85, p = 0.001

0

100

200

300

400

500

600

HW

meth

od

pp

m

0 200 400 600 800 1000 1200

Standard method ppm

Potassiumr2 = 0.072, p = 0.001

0

10

20

30

40

50

HW

Meth

od

pp

m

0 20 40 60 80 100 120

Standard Method ppm

Phosphater2 = 0.35, p = 0.001

6.0

6.5

7.0

7.5

8.0

8.5

HW

Meth

od

s

6.0 6.5 7.0 7.5 8.0 8.5

Standard Methods

pHr2 = 0.67, p=0.001

On the Horizon

• Portability

• GPS and USU - onsite analysis

• Textural Relationships

• E.C.

• S.A.R.

• Instrumentation

Conclusion

• HW is precise and accurate

• HW is more rapid and simple

• HW used less hazardous reagents

• HW minimized equipment and labor

• HW potentially can cut cost

Analysis

• Macro Nutrients - Nitrate, Pottasium, Phosphorus

• Micro Nutrients - zinc, iron, copper, maganese

• Salt conditions - ec

• pH - how acidic or basic your soil is

• Texture - amount of sand, silt and clay

• Organic Matter - how much

Macro Nutrients

• Nitrogen - Minumum levels - 50 ppm**• Nitrogen is the key element in plant growth • Is the most tested for in soils• It is used in the highest quantity by plants • Nitrogen is used in protein synthesis, nucleic

acid production, chlorophyll and other plant substances

• **Nutrional minimum levels may vary depending on several factors

Macro

• Phosphorus - Minumum levels - 15 ppm**• Very tricky to analyze for• Bound by high pH in our soils• Used in ATP production, nucleic acid formation,

fruit and seed production.


Macros

• Potassium - Minimum levels - 100 ppm**• Used in cell division, carbohydrate formation• “Free” spirit in the plant• Availablity affected by pH of soil


Micros• Boron - Minimum levels - 1 ppm**• Used in cell division and growth, membranes• Most toxic of micronutrients• Iron - Minimum levels - 5 ppm**• Used in redox reactions, electron transport• Availability very pH dependent• Zinc - Minimum levels - 1 ppm**• Used to form nitrogen and sulfur ligands, enzymes• Not multivalent• Availability is highly pH dependent• Maganese - Minimum levels - 1 ppm**• Used in enzymes and electron transport• Availability is highly pH dependent • Copper - Minimum levels - 0.2 ppm**• Used in enzymes and electron transfer• Availability is highly pH dependent• Sulfur - Minimum levels - N/A• Mimics nitrogen in the plant and soil• Amino acids, vitamins and oils


Conclusion

• Often, it is easy to make things complicated, but difficult to make things simple.

Soil Analysis The Reasons And Hw Method

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