Soil exam 2

Explain the difference in CEC and soil stability in 2:1 clays 1:1 clays Oxide clays

2:1 more stable, less CEC 1:1 less stable, more CEC Oxide least stable, most CEC

Will plants with a higher or lower carbon nitrogen ratio, tend to add more nitrogen into the soil as they decompose

A lower c:n ratio. They decompose more readily and release nitrogen in a form that is available

How does calcium affect soil aggregation

A positive affect. Leads to the formation of bigger aggregates

What is the difference between absorption and adsorption

Absorb=into adsorb=onto

What are strategies for increasing the soil organic matter?

Adding other organic substances Manure Compost Reducing erosion Reducing tillage

Explain the four mechanisms which lead to soil horizon formation

Additions Losses Transformations Translocations

In aluminum silicate clays, silica tetrahedral sheets alternate with what other type of sheet

Aluminum octahedral sheets

Why do you think soil algae are mostly restricted to the uppermost layers of soil

Because they require light for photosynthesis

R horizon

Bedrock

What are some benefits and negative aspects of using animal manure for fertilizing fields

Benefits: provides essential nutrients, improves soil structure, and recycles organic waste Negatives: risk of nutrient imbalance, presence of pathogens or weed seeds, nutrient runoff and odors

What is the difference between CEC and base saturation

CEC is the total negative charges base saturation is all of the base negative charges

CEC is equal to the acidity and the base saturation, what are the main nutrient bases used to calculate base saturation

Calcium, magnesium, potassium

How does soil texture affect CEC

Clay is negatively charged, the more clay, the more CEC

Which size of soil particles generally has a higher CEC sand, silt, or clay

Clay soils

Will a sand, loam, or clay have the highest CEC

Clay, it has the highest number of negative charged particles

Alfisols

Climate and vegetation dominated Main features: subsurface horizon enriched in clay, good for agriculture

Spodosols

Climate dominated Main features: distinctive Spodic horizon, enriched in organic matter, iron, and aluminum

Aridosols

Climate dominated Main features: dry, desert like soils, minimal leaching, subsurface accumulation of salts

Besides, a map of the types of soils what else is included in a soil survey?

Detailed information about soil properties and classification

E horizon

Eluviation layer l, leached of minerals

Primary consumers

Herbivores that feed on primary producers Soil dwelling. Beetles, springtails Nematodes. Microscopic roundworms

Will a high concentration of hydroxyl ions create a low or high PH

High

Which ion is given off by plant roots in exchange for nutrient cations

Hydrogen ions/ H+

How can earthworms be detrimental to forest, soil and forest ecology

If they are a non native species. They disrupt the natural forest floor.

Name four micro nutrients

Iron, manganese, zinc, and copper

How does the soil texture affect soil nutrient availability to plants?

It affects it because of factors like water retention, aeration, and CEC

Why is pH important for plant nutrition?

It affects the availability of essential nutrients in the soil

What is humus? How does it differ from other soil organic material?

It is a dark organic matter that forms from the decomposition of plants and animals

Name an oxide clay

Kaolinite

List the main types of soil colloids

Layered clays Oxide clays Humus

Does a high concentration of hydrogen ions create a soil with a low ph or high ph

Low/Decrease

Are aluminum ions associated with higher or lower PH

Lower PH

Decomposers

Microorganisms that break down organic matter into simpler substances Bacteria Fungi Earthworms Protists

Which soil order are the soils in majority of soil in Saginaw Valley?

Mollisols

Name two main soil orders found in most of Michigan's lower peninsula. How do these two soil types affect how the land is used in the northern and southern parts of the lower peninsula

Mollisols in the lower, spodosols in the upper. Mollisols are used more for agriculture in the lower, while spodosols have limitations for agriculture

If a commercial fertilizer list the main nutrients as 20-10-5, what does that mean? If it is 100 pounds how many pounds of phosphorus does it have? How many pounds of potassium? And nitrogen?

N-P-K 20pounds nitrogen, 10 pounds phosphorus, 5 pounds potassium

How does sodium affect soil aggregation

Negative, disperses soil particles, reducing aggregation

Be able to label the steps of the nitrogen cycle

Nitrogen fixation Nitrification Assimilation Ammonification Dentrification

Name three ways atmospheric nitrogen is made available for plant use

Nitrogen fixing bacteria Lightning Fertilizers

Name three different different processes by which nitrogen becomes available for plants

Nitrogen fixing bacteria Nitrification Decomposition

Name three elements which are derived from the atmosphere

Nitrogen, oxygen, and carbon dioxide

List some other types of fertilizing used by farmers besides commercial dry/liquid chemical fertilizers

Organic fertilizers Slow release fertilizers Bio stimulants

O horizon

Organic horizon, rich in organic matter

Shredders

Organisms that break down organic matter Woodlice Leaf cutter ants

Predators

Organisms that feed on other organisms Ground beetles Centipedes Wolf spiders

Primary producers

Organisms that produce their own food Plants/algae

What are the to main sources on clay colloids

Oxygen at crystal edges Isomorphism substitution

Mollisols

Parent material dominated Main features: dark fertile soils, thick dark A horizon, grasslands, highly productive for ag

C horizon

Parent material, little weathering

Name four plant, macro nutrients, excluding nitrogen, and where they come from

Phosphorus- derived from rock minerals and organic material Potassium- found in soil minerals Calcium- derived from limestone and other calcium rich minerals Magnesium- comes from minerals like dolomite and serpentine

Both bacteria and fungi can have symbiotic relationships with plants in the Rise Osphere how do plants benefit in this relationship? How do the bacteria/fungi benefit?

Plants- they obtain nutrients and absorption rates increase Fungi- they receive carbohydrates and other organic compounds

Name two layered clays

Smectite Illite

B horizon

Subsoil, accumulated minerals and leached materials

Explain the Rhizosphere, and it's important in plant nutrition

The area of soil surrounding plant roots where the plant can take up nutrients

How are earthworms beneficial in agricultural soil?

They improve soil structure by burrowing and mixing organic matter

What important functions do macro organisms play in both soil, fertility, and soil structure

They physically break down organic matter and create pore spaces for air and water, they also mix the soil

What important functions do microorganisms play in both soil, fertility, and soil structure

They play the role of decomposition and breaking down complex compounds into ones plants can use

What major role do plants play in the soil food web?

They play the role of primary producers, starting the food web

A horizon

Topsoil, organic matter mixed with minerals

Histosol

Vegetation dominated Main features: high content of organic matter, wetland/ peatland environments

Besides, a laboratory analysis of soil, nutrients briefly explained to other ways to determine plant nutritional deficiencies

Visual symptoms on plant leaves Nutrient deficiency testing kits

Where to nutrient cations come from which attach to soil colloids

Weathering of minerals Organic matter decomposition Fertilizers