Soil Testing
What impact does pH have on plant growth? |
Soils are complex combination of inorganic materials (not carbon-based), orgainc materials (cabon-based), and living organisms. Various combinations of these materials can yield soils that are infertile (no plant growth), semi-fertile (some plant types will grow but others will not) and very fertile (most plant types will grow in it). Soil that supports plant growth has many characteristics:
* Porous, allowing air and water to filter through. * Contains lots of humus (dead plant material), which retains moisture needed for new plant growth. * Has a pH that is in the newutral zone (pH of 6-7.5) and can resist changes in pH. * Does not contain too much salt. *Has thriving population of decomposers (earthworms, ants, beetles, fungi, bacteria etc.) that break sown materials to the smallest building blocks that can be used by plants for growth. |
Soil pH Lab
Soil pH Lab Directions
Soil pH Data Collection Sheet
Soil pH Lab Analysis
Water and pH Directions
Water and pH Lab
Determining Soil Quality Directions
What impact does salinity have on plant growth? |
Soil salinity is a measurement of water soluble salts that are present in soil. Salts are a widespread and natural component of all soils; however, an increase in salt concentration will adversely affect the growth of agricultural crops, decrease productivity, and threaten the balance of the Earth's soil layer. As the minerals in soils weather, they release salts. These salts are leached out of the soil by ground or surface water in areas with sufficient precipitation. In addition to weathering, salts are also deposited via dust and precipitation. In dry regions, salts may accumulate over time leading to naturally saline soils. The distribution of salt in soils is ultimately determined by the geology of the land. Over-fertilizing and improper irrigation techniques aggravate pre-existing soil salinity conditions. Soil salinity is one property of soil that can be assessed to determine the soils health. Soil salinity can be measured using a conductivity sensor.
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