Most Often Missed onDIRT! Lab

Part 1 - Texture

• 1 a) & b): Use the Pyramid’s vocabulary• Example: Sandy loam, Clay Loam, etc.

• 2: More tests will provide more reliable results. Texture is only one characteristic of soil and can be subjective. Other characteristics like permeability and particle size will provide more evidence.

Part 1 - Sieve

• 2: The smaller the particles, the more water is able to be held. Example: Clay & Silt hold a lot of water. Sand does not.

• 6: N, K, P • 7: Dark soil consists of silt and organic matter thus may

come from a deciduous forest in a temperate climate, including parent material like decomposing logs, leaves, and other organisms. Light soil consists of gravel, sand and other large particles, thus the parent material may be from larger stones or from soil near a beach.

Part 2 - pH

• 5: Soil pH is important because it determines the availability of nutrients in the soil. The most important nutrients (like N, P, K) are most available near neutral pH values. IF the soil pH is too acidic or basic, a plant may die because of the lack of required macronutrients.

Part 3 - Permeability

• 2: Light sample: Sand, gravel (+ some clay, +silt) Dark sample: silt (+some clay, +sand)

• 3: A farmer needs to make sure that the soil has good permeability so that the water can infiltrate the soil and reach the roots of his/her crops. However, the soil must not be too permable because then the water will infiltrate too fast and flow through the soil before the roots can uptake the water.

• 4: The darker sample held more soil, because it’s mostly made of silt which consists of smaller particles than sand or gravel. The lighter sample is made up of sand and gravel which does not hold water very well because the particles are larger.