Soil Science Independent Quiz

Which of the following best describes how soils are formed?

• As plants and animals break down, the carbon in their bodies turns into minerals that plants eat to survive.
• Over thousands of years, rocks are weathered down to small particles that mix with small amounts of decaying organic matter and living organisms.
• As animals consume plants, they convert the plant matter into minerals. The feces from the animals then forms the soil.
• Over thousands of years, carbon dioxide in the air converts into minerals that fall to the ground and form soil.

This is the largest soil particle

• Clay
• Silt
• Sand
• Loam

This has the smallest amount of pore space for air and water

• Clay
• Silt
• Sand
• Loam

This is the least likely to undergo compaction, but most at risk for erosion

• Clay
• Silt
• Sand
• Loam

This is the most ideal soil for plant growth and productivity

• Clay
• Silt
• Sand
• Loam

This consists of an even mixture of different sizes of soil particles

• Clay
• Silt
• Sand
• Loam

This generally has the lowest cation exchange capacity? (CEC)

• Clay
• Silt
• Sand
• Loam

The higher the cation exchance capacity (CEC) of a soil sample, the....

• Weaker the soil's capacity to hold onto water and nutrients
• Stronger the soil's capacity to hold onto water and nutrients
• Greater the risk of nutrient leaching
• Greater the porespace

How do factors such as pore space and compaction affect plant growth?

• Compacted soils reduce the availability of water and oxygen to plant roots
• Soils with large amounts of porespace enable roots to absorb more water and soil
• Soils with small amounts of porespace are less likely to undergo nutrient leaching
• Compacted soils have less porespace, which reduces the availability of water, nutrients and oxygen
• All of the above are accurate

Which of the following is an accurate statement in regards to soil pH?

• pH is a measure of the particle size
• a pH of 7 indicates very acidic soil
• a pH of 7 indicates high organic matter
• pH indicates how basic or acidic the soil is, a pH of 6 is ideal