soil testing and fertilizing recommendations
TRANSCRIPT
SOIL TESTING AND FERTILIZER RECOMMENDATION
Leonard Githinji, Ph.D.
Assistant Professor / Extension Hort. Specialist
Tuskegee University Cooperative Extension Program
Tuskegee, Alabama
SOIL TESTING AND FERTILIZER RECOMMENDATION
INTRODUCTION
The goal of this soil testing and fertilizer recommendation webinar is to provide Extension agents and other personnel with the necessary tools for better understanding and interpretation of soil test reports.
SOIL TESTING AND FERTILIZER RECOMMENDATION
INTRODUCTION Cont.
Efficient use of fertilizers is a major factor to consider for any successful farming.
Several benefits of efficient fertilizer use have been outlined.
SOIL TESTING AND FERTILIZER RECOMMENDATION
INTRODUCTION Cont.
These benefits include:
profit maximization for producers
lower cost for consumers and
enhancement of environmental (environmental protection).
SOIL TESTING AND FERTILIZER RECOMMENDATION
INTRODUCTION Cont.
Without soil test and fertilizer recommendation, a farmer may be applying:
too much of a little needed plant food element or
too little of another element which is actually the principal factor limiting plant growth.
SOIL TESTING AND FERTILIZER RECOMMENDATION
ESSENTIAL PLANT NUTRIENT ELEMENTSESSENTIAL PLANT NUTRIENT ELEMENTS There are 16 essential nutrients that are required by plants.
The essential nutrients are grouped as:
Primary Nutrients
Secondary Nutrients
Micronutrients
SOIL TESTING AND FERTILIZER RECOMMENDATION
ESSENTIAL PLANT NUTRIENT ELEMENTSESSENTIAL PLANT NUTRIENT ELEMENTS There are 16 essential nutrients that are required by plants.
The essential nutrients are grouped as:
Primary Nutrients
Secondary Nutrients
Micronutrients
Macronutrients
SOIL TESTING AND FERTILIZER RECOMMENDATION
ESSENTIAL PLANT NUTRIENT ELEMENTS Cont.ESSENTIAL PLANT NUTRIENT ELEMENTS Cont. Primary Nutrients: Utilized in the largest amounts by
crops, and therefore, are applied at higher rates.
Secondary Nutrients: Required in smaller amounts than the primary nutrients.
Micronutrients: Required in even smaller amounts than secondary nutrients.
SOIL TESTING AND FERTILIZER RECOMMENDATION
Nutrients from Air and Water
Nutrients from Soil, Lime and Commercial Fertilizers
Primary Nutrients
Secondary Nutrients
Micronutrients
Carbon (C) Nitrogen (N) Calcium (Ca) Boron (B)
Hydrogen (H) Phosphorous (P) Magnesium (Mg) Chlorine (Cl)
Oxygen (O) Potassium (K) Sulfur (S) Copper (Cu)
Manganese (Mn)
Molybdenum (Mo)
Zinc (Zn)
Plant Nutrients and their Major Sources
SOIL TESTING AND FERTILIZER RECOMMENDATION
PLANT NUTRIENT DEFICIENCYPLANT NUTRIENT DEFICIENCY
Terminologies used for description of nutrient deficiency symptoms:
Chlorosis: insufficient chlorophyll
General Chlorosis
Interveinal Chlorosis
SOIL TESTING AND FERTILIZER RECOMMENDATION
PLANT NUTRIENT DEFICIENCY Cont.PLANT NUTRIENT DEFICIENCY Cont.
Terminologies used for description of nutrient deficiency symptoms: Cont.
Coloration abnormalities: change from normal color
Firing: Yellowing, followed by rapid death of leaves
Necrosis: death of the entire plant Stunting: decreased growth
SOIL TESTING AND FERTILIZER RECOMMENDATION
Nutrient Essential Function Deficiency Symptoms
Nitrogen (N) -proteins
-enzymes
-stunting
-chlorosis (older leaves)
Phosphorous (P)
-DNA
-reproduction
-purple (older leaves)
-stunting
Potassium (K) -enzymes function
-transpiration
-marginal necrosis (tip burn)
-interveinal chlorosis
Calcium (Ca) -part of cell walls
-nutrient uptake
-distortion (new leaves)
-blossom-end rot
Magnesium (Mg)
-chlorophyll molecule
-interveinal chlorosis (older leaves)
-necrosis in chlorotic tissue
Sulfur (S) - protein
-enzymes
-chlorosis (new leaves)
Plant Nutrients Role and Deficiency Symptoms
SOIL TESTING AND FERTILIZER RECOMMENDATION
Plant Nutrients Role and Deficiency Symptoms
SOIL TESTING AND FERTILIZER RECOMMENDATION
Plant Nutrients Role and Deficiency Symptoms
SOIL TESTING AND FERTILIZER RECOMMENDATION
Effect of pH on Plant Nutrients
SOIL TESTING AND FERTILIZER RECOMMENDATION
SOIL TESTINGSOIL TESTING
Soil Testing: A process by which elements are chemically removed from the soil and measured for their "plant available" content.
Soil should be tested every two to three years to determine the amount of nutrients needed.
Fertilizer application rates are calculated based on the crop needs and soil test results.
SOIL TESTING AND FERTILIZER RECOMMENDATION
Soil Testing ProcessSoil Testing Process
Sampling:
time (~1-2 weeks before)
depth (6-7 inches)
number (15-20 samples)
composite samples
pattern (zigzag)
locations (multiple places)
SOIL TESTING AND FERTILIZER RECOMMENDATION
Soil Testing Process
SOIL TESTING AND FERTILIZER RECOMMENDATION
Soil Testing Process Cont.Soil Testing Process Cont.
Sampling Equipment:
Shovel
Trowel
Bucket
Information sheet
Shipping box
SOIL TESTING AND FERTILIZER RECOMMENDATION
Soil Testing Process Cont.Soil Testing Process Cont.
Sampling Equipment:
SOIL TESTING AND FERTILIZER RECOMMENDATION
Soil Testing Process Cont.Soil Testing Process Cont.
Analyzing the sample
Chemical extraction and testing is done in the laboratory.
Laboratories may use different extraction and analysis techniques.
The procedures used must be correlated to plant growth and nutrient uptake.
In addition, quality control by the staff is essential for reliable and accurate results.
SOIL TESTING AND FERTILIZER RECOMMENDATION
Soil Testing Process Cont.Soil Testing Process Cont.
Soil Test Results
SOIL TESTING AND FERTILIZER RECOMMENDATION
FERTILIZER AND RECOMMENDATIONFERTILIZER AND RECOMMENDATION Some Common Terms used in Fertilizer Industry
Complete Fertilizer: A fertilizer containing the three primary nutrients, N, P2O5, K2O.
Fertilizer Grade: Refers to the minimum guaranteed % of N, P2O5, K2O e.g. 4-16-8.
Fertilizer Ratio: Refers to the relative proportion of N, P2O5, K2O e.g. 1:4:2.
Fertilizer formula: The quantity and analysis of the fertilizer materials making up a mixed fertilizer.
SOIL TESTING AND FERTILIZER RECOMMENDATION
FERTILIZER AND RECOMMENDATION Cont.FERTILIZER AND RECOMMENDATION Cont. Fertilizer Grade
Available Nitrogen (N)
Available potash (K2O)
Available phosphate (P2O5)
SOIL TESTING AND FERTILIZER RECOMMENDATION
FERTILIZER AND RECOMMENDATION Cont.FERTILIZER AND RECOMMENDATION Cont. Calculation of Nutrient Content in a Fertilizer
N = 10/100 X 50 lbs = 5 lbs
K2O = 10/100 X 50 lbs = 5 lbs
P2O5 = 10/100 X 50 lbs = 5 lbs
Total Nutrients = 15 lbs
Filler material = 35 lbs
SOIL TESTING AND FERTILIZER RECOMMENDATION
FERTILIZER AND RECOMMENDATION Cont.FERTILIZER AND RECOMMENDATION Cont. Calculation of Nutrient Content in a Fertilizer
N = 10/100 X 50 lbs = 5 lbs
K2O = 10/100 X 50 lbs = 5 lbs
P2O5 = 10/100 X 50 lbs = 5 lbs
Total Nutrients = 15 lbs
Filler material = 35 lbs
SOIL TESTING AND FERTILIZER RECOMMENDATION
FERTILIZER AND RECOMMENDATION Cont.FERTILIZER AND RECOMMENDATION Cont. Calculation of Fertilizer From Soil Test Results
SOIL TESTING AND FERTILIZER RECOMMENDATION
Calculation of Fertilizer From Soil Test Results Cont.
Using Fertilizer MixesNeeded (lbs/Acre)
Fertilizer Calculation Amount
lbs bags
K2O (120) Potash
(0:0:60)
120/0.60 200 4
P2O5 (60) DAP
(18:46:0)
60/0.46 130 3
N (120) Urea
(46:0:0)
(120/0.46)-(60/0.46 x 0.18) = (260)-(23)
237 5
SOIL TESTING AND FERTILIZER RECOMMENDATION
Calculation of Fertilizer From Soil Test Results Cont.
Using Custom Blended FertilizersNeeded (lbs/Acre)
Ratio Blend Calculation Amount
lbs bags
K2O (120) 2 20
P2O5 (60) 1 10 60/0.1 600 12
N (120) 1 10
SOIL TESTING AND FERTILIZER RECOMMENDATION
Calculation of Fertilizer From Soil Test Results Cont.
Price ComparisonType Fertilizer price Total
Common Fertilizer
Mixes
Potash
4 bags x $15
DAP
3 bags x $30
Urea
5 bags x $25
$275
Custom Blended Fertilizer
12 bags X $25 $240
THANK YOU
Please feel free to contact me for any questions or further discussions
Leonard Githinji, Ph.D.Assistant Professor / Extension Hort. Specialist204 Vocational Building, Tuskegee University
Tuskegee, AL 36088Tel: 334-724-4955Fax: 334-727-8268
Email: [email protected]