SOIL ANALYSIS
ARCHIBONG EDEM
PUBLIC HEALTH DEPARTMENT, UNIVERSITY OF CALABAR
PUH/Ph.D/22/003
OUTLINE
Introduction
Understanding Soil Composition
Soil
Soil Formation
Composition of Soil
Importance of Soil
Important of soil analysis
Purpose of soil analysis
Methods of Soil Sampling
Soil Analysis Process
Outline cont.
Objectives of Soil Analysis
Soil Sample Collection
Laboratory Analysis
Interpretation of Results
Additional Tests
Conclusion
Reference
Introduction
Soil analysis involves the
scientific assessment of soil
properties, composition, and
quality. It typically includes
testing for
This process is essential for
understanding the suitability
of soil for agriculture,
construction, and
environmental conservation.
• pH levels
• nutrient content
• texture
• and organic matter
UNDERSTANDING SOIL COMPOSITION
• Soil composition refers to the combination of organic and inorganic
materials that make up the soil
WHAT IS SOIL?
A natural body that occurs on the surface of the earth.
Composed of mineral and organic matter, water, and air.
Capable of supporting plant life.
A product of physical, chemical, and biological processes acting over time.
Classification of soil
Clay Soil
Sandy soil
Loamy Soil
Silt Soil
IMPORTANCE OF SOIL
• The fertile soil helps in the growth and development of the plants. The plants thus produced are healthy
and provide food, clothing, furniture, and medicines.
• It supports many life forms including bacteria, fungi, algae, etc. These microbes, in turn, maintain
environmental balance by retaining the moisture and decaying the dead organisms.
• The topsoil supports certain life activities such as reproduction, hatching, nesting, breeding, etc. of a
few organisms.
• The organic matter present in the soil increases the fertility of the soil which is responsible for the
growth of the plants. It also contains certain minerals and elements that are necessary for the plants to
carry out their cellular activities.
IMPORTANCE OF SOIL CONT.
• Soil is used for making cups, utensils, tiles, etc. The contents in the
soil such as gravel, clay and sand are used in the construction of
homes, roads, buildings, etc.
• Useful mineral medicines such as calcium, iron, and other substances
such as petroleum jelly for cosmetics are extracted from the soil.
• The soil absorbs the rainwater. This water is evaporated and released
into the air during sunny days, making the atmosphere cooler.
SOIL ANALYSIS
Soil analysis is a valuable farm practice that determines the exact amount of available crop
nutrients in the soil. It also provides a visible snapshot of various chemical, physical, and
biological soil properties. Some of the most basic but necessary micronutrient
measurements include:
• Determining levels of nitrogen, phosphorus, potassium, magnesium, and calcium
• Analyzing soil pH
• Determining humus content, available lime, and organic matter
IMPORTANCE OF SOIL ANALYSIS
• Improved crop yields: Soil testing can identify nutrient deficiencies or imbalances that may be limiting
plant growth and yield, enabling growers to adjust their fertilization practices and optimize crop yields.
• Reduced fertilizer costs: Soil testing can also help growers avoid over-application of fertilizers, which can
be costly and have negative environmental impacts.
• Improved soil health: Soil testing can provide valuable insights into soil health, including organic matter
content, pH, and texture. By managing soil health appropriately, growers can improve soil structure,
nutrient cycling, and water retention.
• Precision farming: Soil testing can help growers identify areas of their fields with different soil
characteristics and nutrient needs, allowing for more targeted fertilization and other management
practices.
• Environmental protection: By avoiding over-application of fertilizers and other soil amendments, growers
can reduce the risk of nutrient runoff and associated environmental problems.
PURPOSE OF SOIL ANALYSIS
Provide insights into soil composition, strength, and behavior for construction projects.
Assess soil fertility and make fertilizer recommendations.
Determine available plant nutrients and other soil properties important for plant nutrition.
Reduce the risk of soil erosion, infertility, and degradation.
Ensure efficient and economic crop production by optimizing fertilizer
TYPES OF SOIL ANALYSIS
• Physical Soil Tests: Assess soil structure, texture, density, permeability, porosity, temperature, plasticity, and
aggregate stability.
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Chemical Soil Tests: Analyze pH, phosphorus, potassium, magnesium, and calcium.
Total Nutrient Digestion (TND).
pH/Soil Acidity Tests.
Soil Salinity Tests.
Haney Tests.
PLFA Tests.
Microscopy.
SOIL TESTING METHODS
Choosing sampling locations
Collecting soil samples
Analyzing the soil samples in laboratories
Interpreting the test results
DIY methods such as the ribbon test, aggregate stability, earthworm count, and pH test.
KEY STEPS FOR SOIL TESTING
Choosing the
sampling
locations
Interpretation
of the result
Collection of
sample
Analyzing the
soil samples
HOW USE THE RESULTS OF A
BIOLOGICAL SOIL TEST TO IMPROVE
SOIL HEALTH
• Identify the key issues: Review the results of your biological soil test to identify any issues or imbalances that need to be
addressed. For example, you may need to increase the population of beneficial microorganisms, reduce the population of harmful
microorganisms, or improve soil structure.
• Choose appropriate management practices: Based on your biological soil test results, choose appropriate management
practices to address the identified issues. This may involve using cover crops, reducing tillage, adding organic matter, or applying
microbial inoculants.
• Monitor progress: Regularly monitor your soil health and the effectiveness of your chosen management practices to ensure that
you are making progress toward your goals. This may involve conducting regular soil tests, observing plant growth and yield, or
measuring soil organic matter levels.
• Adjust management practices as necessary: If you are not seeing the desired improvements in your soil health, adjust your
management practices as necessary. This may involve trying different types of cover crops, adjusting nutrient applications, or
experimenting with different tillage practices.
• Continuously improve: Remember that soil health is an ongoing process, and there is always room for improvement. Regularly
assess your soil health, experiment with new management practices, and stay current on the latest research and trends in soil health
management.
DRAWBACKS OF BIOLOGICAL SOIL
TESTING METHODS
•
Cost: Biological soil testing methods can be more expensive than traditional chemical testing methods. This is
because they often involve more complex laboratory procedures and specialized equipment.
• Time: Biological soil testing methods can take longer to yield results than traditional chemical soil testing
methods. This is because they often involve more complex laboratory procedures and may require longer
incubation periods.
• Complexity: Biological soil testing methods can be more complex and require more expertise to interpret than
traditional chemical soil testing methods. This is because they often involve measuring a wider range of soil
parameters and require a deeper understanding of soil biology.
• Variability: The results of biological soil testing methods can be more variable than traditional chemical soil
testing methods. This is because biological soil health is influenced by many different factors, including climate,
soil type, and land use history, which can vary from one location to another.
• Limited standardization: There is currently limited standardization of biological soil testing methods, making it
difficult to compare results across different labs and locations.
SOIL ANALYSIS PROCESS
• Soil Fertility Maintenance: it helps maintain soil fertility by identifying nutrient
deficiencies and imbalances, enabling targeted nutrient replenishment.
• Improved Crop Yields: It optimizes crop yields by ensuring that plants have access
to the necessary nutrients for healthy growth and development.
• Soil Health Monitoring: It allows farmers to monitor changes in soil fertility over
time, enabling them to make adjustments to their management practices as needed.
SOIL ANALYSIS PROCESS
• Sample Collection: Soil samples are collected from various areas of a field using appropriate
sampling techniques.
• Laboratory Analysis: The collected samples are sent to a soil testing laboratory for analysis.
• Nutrient Determination: The laboratory conducts various chemical tests to determine the
nutrient levels and other properties of the soil.
• Interpretation and Recommendations: The results of the analysis are interpreted by experts, who
provide fertilizer application recommendations based on the specific crop requirements and soil
conditions
• Interpretation and Recommendations: The results of the analysis are interpreted by experts, who
provide fertilizer application recommendations based on the specific crop requirements and soil
conditions
SOIL SAMPLE COLLECTION
The initial step in soil analysis is the collection of soil samples from the desired
area. To ensure representative samples, the collection should be done at a
consistent depth and in a random manner. A common method is composite
sampling, where sub-samples are taken from randomly selected locations and
thoroughly mixed to obtain a representative sample.
LABORATORY ANALYSIS
In the laboratory, the soil samples undergo analysis to determine their nutrient content and
other properties. This involves mixing the soil with a strong extracting solution, often an acid
or a combination of acids, to release nutrients from the soil particles. The extracted solution is
then analyzed to measure the levels of essential plant nutrients such as phosphorus (P),
potassium (K), magnesium (Mg), and others. Additionally, soil pH, which indicates the acidity
or alkalinity of the soil, is also measured.
INTERPRETATION OF RESULTS
Soil test reports provide information on the measured soil fertility levels and
nutrient recommendations. The results are often presented in numerical values
and bar charts, indicating whether the nutrient levels are below optimum,
optimum, or above optimum for plant growth. This information helps in
making informed decisions regarding fertilizer application and other soil
management practices.
ADDITIONAL TESTS
In some cases, additional tests can be conducted during soil analysis to assess
factors such as organic material content, nitrate levels, trace mineral
concentrations, and soil acidity. These tests provide a more comprehensive
understanding of the soil’s properties and help in addressing specific soilrelated issues or concerns.
CONCLUSION
In conclusion, soil testing is an essential tool for growers and farmers to
evaluate the health and productivity of their land. By analyzing the soil texture,
structure, and nutrient content, growers can make informed decisions about
crop management practices, such as irrigation, fertilization, and soil
amendment. The soil testing results can also be used to identify potential soil
health issues and develop soil improvement plans to optimize crop yields and
long-term sustainability
REFERENCE
•
Agrivi https://www.agrivi.com/blog/why-successful-farmers-practice-soil-analysis Comprehensive Analytical Chemistry Volume 54, 2008,
Pages 685-760
•
•
https://www.perlego.com/index/geography/soil-analysis Overview of soil analysisPerlego with AI-assistanc
•
Penn State Extension. (2023). Interpreting Your Soil Test Reports. Penn State University. https://extension.psu.edu/interpreting-your-soiltest-reports
•
Soil Analysis: A key to soil nutrient management | New Mexico State University – BE BOLD. Shape the Future.
(https://pubs.nmsu.edu/_a/A137/)
•
The Importance of Soil Analysis in Agriculture – AGRIVI (Walworth, J. L. (2008). Soil Sampling and Analysis. University of Arizona
Cooperative Extension. https://cals.arizona.edu/backyards/sites/cals.arizona.edu.backyards/files/p16-17.pdf
•
University of Massachusetts Amherst. (n.d.). Soil Testing. Center for Agriculture, Food, and the Environment.
https://ag.umass.edu/greenhouse-floriculture/greenhouse-best-management-practices-bmp-manual/soil-testing
•
What is Soil Analysis? – CROPNUTS Helpdesk (https://cropnuts.helpscoutdocs.com/article/837-what-is-soil-analysis)
https://www.sciencedirect.com/topics/chemistry/soil-analysis Moment Engineering July 23,2023 https://momentengineering.us/learn/theimportance-of-soil-sampling-and-testing
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