Unit 3 Quest Review: Soils

What soil horizon contains topsoil and is the most productive for plants?

A Horizon.

Soil.

A system consisting of disintegrated rock, organic matter, water, gases, nutrients, and microorganisms. Soil is derived from rock sediments, but shaped by microorganisms.

Sandy soils.

Are porous and allow water to pass through - but too quickly, requiring frequent irrigation.

Five factors weathering is accumulated by.

Climate: Warm, moist climates accelerate most weathering processes. Organisms: Plants and decomposers add organic material. Topography: Hills and valleys affect exposure to sun, wind, water, and influence soil movement. Parent material: Its composition influences soil formation. Time: Soil formation can take centuries, decades, or millennia.

What does soil structure measure?

Clumpiness of soil (soil that is heavily clumped is considered compacted and cannot absorb water as well).

Soil texture.

Determined by size of its particles.

Mutualistic relationship.

EX: The fungi provides water and nutrients, while the plant provides carbohydrates from photosynthesis.

Soil texture order.

From largest to smallest: sand, clay, slit.

Clay soils.

Have small pore spaces and are sticky, making it difficult for air and water to pass through and get to roots.

Weathering.

How parent material is broken down.

Soil color.

Indicated fertility.

Leaching.

Minerals dissolved or suspended in water can be transported downward in a process called this.

Soil horizon layers.

Only Americans Eat Bacon Covered Ribs.

Humus.

Partially-decomposed organic matter is called this, and is very productive for plant life.

Physical vs. chemical vs .biological weathering.

Physical results from wind, rain, freezing, and thawing. Chemical occurs as water or gases chemically alter rock. Biological involves living things such as lichens producing acid or tree roots rubbing against rock.

Agriculture support.

Plants need soil to provide nutrients for growth, structure for rooting, and a medium to hold water and nutrients for absorption through roots.

Sediments.

Rocks and minerals moved and deposited in a new location. Soil consists of sediments and the remains of plants and animals.

What is the ideal soil texture for plant agriculture? Soil with mostly clay particles. Soil with mostly sand particles. Soil with a mixture of silt, clay, and sand particles (loam). Soil texture does not affect the success of plant agriculture.

Soil with a mixture of silt, clay, and sand particles (loam).

Loam.

Soil with an even mixture of each particle is called this.

pH soil values.

Soils of pH values near 7 are best for plants. Soil that is too acidic or alkaline may inhibit the absorption of nutrients, leading to plant death.

Parent material.

The base geologic material in a particular location. This may include: Bedrock, the mass of solid rock that makes up most of the Earth's crust. Bedrock underlies all soil and sediment everywhere! Hardened lava or volcanic ash. Sediment deposited by glaciers or flowing water. Wind-blown dunes.

Soil horizon.

The movement and sorting of soil particles creates distinct layers called this.

Soil profile.

The whole cross section of the soil is the soil profile. Generally, the degree of weathering and concentration of organic matter decrease as one moves downward in a soil profile.

Which of these factors or changes would increase the rate of weathering and accumulation of organic matter in soil? Less time. Increased sheltering by hills. Warmer climate. Fewer plants and decomposers.

Warmer climate.

Primary succession.

Where soil formation begins. Water, air, and living organisms break down parent material in the lithosphere into sediments.

Loam soils.

With medium-sized pores, these are considered the best for agriculture.