Soil testing
ph, ec
moisture content
mineral content
Size: 4.54 MB
Language: en
Added: Sep 05, 2024
Slides: 23 pages
Slide Content
ENVIRONMENTAL MEASUREMENT OF SOIL, TLA 5204 Element 2
PC 2.1 Identify environmental test planners and effect liaise in accordance with policies and procedures. 2.2 Implement, monitor and amend test plan based on changing circumstances in accordance with methodologies and procedures
What is soil? Soil is the loose upper layer of the Earth's surface where plants grow. Soil consists of a mix of organic material (decayed plants and animals) and broken bits of rocks and minerals. Organic - The organic layer (also called the humus layer) is a thick layer of plant remains such as leaves and twigs. Topsoil -It is a fairly thin layer (5 to 10 inches thick) composed of organic matter and minerals where plants and organisms live. Subsoil - Subsoil is considered the "B" horizon. This layer is made primarily of clay, iron, and organic matter. Parent material - The parent material layer is considered the "C" horizon. This layer is called the parent material because the upper layers developed from this layer. It is made up mostly of large rocks. Bedrock - The bottom layer is several feet below the surface. And is made up of a large solid mass of rock.
SOIL TESTING A soil test is important for several reasons: to improve crop production , to protect the environment from contamination by runoff and leaching of excess fertilizers, to analyse plant culture problems , to improve the nutritional balance of soil. used to identify application rates of waste materials containing nutrients or other elements that could harm the environment. Soil testing is required in many regulations and management guidelines to assess environmentally harmful levels of certain elements and to determine limits to application rates.
Soil pH Measures the activity of hydrogen ions in soil water. pH is an indicator of whether the soil is acidic, neutral, or basic . When a plant's soil pH increases, the plant's ability to absorb certain nutrients is disrupted. As a result, some nutrients cannot be absorbed properly. For example, if a plant's leaves become yellow between the veins, this indicates an iron deficiency. https://www.youtube.com/watch?v=zQowljL8e5E
pH 5.5 – 8 is favorable for plant growth Nutrient availability Microbial activity
Soil Moisture Soil moisture is the water present in the space between the soil particles. Soil moisture influences the physical, chemical, and biological characteristics of the soil . Soil moisture is the percentage of moisture (on a weight basis) in a soil sample at any given time. It shows general moisture content of the soil . https://www.youtube.com/watch?v=zAWmim01DKg
The gravimetric method of moisture estimation is most widely used where the soil sample is placed in an oven at 105 °C and dried to a constant weight. The difference in weight is considered to be the water present in the soil sample. Soil Moisture meter
Soil respiration: •Measures the amount of CO2 released from the soil . Soil Respiration is an indicator of biological activity and soil health. Soil respiration is a measure of carbon dioxide (CO2) released from the soil by : decomposition of soil organic matter by soil microbes and respiration from plant roots and soil fauna.
Soil respiration is a measure of the carbon dioxide released from the soil by microbes decomposing soil organic matter and from the respiration of plant roots. Soil respiration indicates soil health (soil organic matter content, soil organic matter decomposition and the level of microbial activity). Respiration: Release of carbon dioxide from several sources (decomposition of soil organic matter by soil microbes, and respiration from plant roots
Electrical conductivity of Soil Measures how well an electrical current travels through the soil water. Electrical conductivity is an indicator of how much salt is present in the soil. Soils with high EC due to high concentration of sodium generally have poor structure and drainage, and sodium becomes toxic to plants
Soil Infiltration Infiltration: Measures how fast water can infiltrate into the soil Infiltration is an indicator how easily water will infiltrate, pond, or runoff during rainfall or irrigation. Soil infiltration refers to the ability of the soil to allow water to move into and through the soil profile. Infiltration allows the soil to temporarily store water, making it available for use by plants and soil organisms. The infiltration rate is a measure of how fast water enters the soil, typically expressed in inches per hour
https://www.youtube.com/watch?v=YsEYs3YfkKE
Penetration Resistance Penetration resistance: Measures the force required to insert a metal rod into the soil. Resistance is an indicator of how easily roots can grow in the soil. Soil penetration resistance is an important physical characteristic that may be measured directly in the field. https://www.youtube.com/watch?v=llHwqWWpkqU
NITRATE Nitrate: Measures the amount of nitrate in the soil . Nitrate is an important nutrient for plant. The amount required in the soil for specific crops varies from crop to crop, but in general the levels should not fall below 10 mg/kg and should not exceed 50 mg/kg. Dip a nitrate / nitrite test strip into the water and estimate the nitrate or nitrite concentration from the color chart on the test strip bottle. This test can give you an idea of how much N fertilizer is lost from the soil .
Sixteen essential Nutrients Macronutrients are nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S) Micronutrients are obtained from the soil. They are boron (B), copper (Cu), chlorine (Cl), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn).
Nitrogen, phosphorus and potassium The most important nutrients are called macronutrients. Needed small quantities are called micronutrients. NITROGEN: Nitrogen is necessary for new growth and green plants . Nitrogen is absorbed as nitrate (NO3)- or ammonium (NH4)+. PHOSPHORUS : The molecule that provides energy for all living th ings is called Adenosine Triphosphate (ATP). POTASSIUM : Potassium ion (K+) is needed to control the water uptake in the plant
Testing nitrogen, phosphorus and potassium Collect multiple samples from different areas of your garden, being careful to take from the same depth in each location and to avoid contamination; Soil Test tablet Grab soils sample deep 2-6 inches Mix with dis-water Dilute Tear open the " FLOC EX" foil and drop one tablet into the graduated cylinder. compare the color of the liquid with the chart for Nitrogen
Steps for analysis of NPK
https://www.youtube.com/watch?v=DRvHQNyAgQg Soil testing using kit