Biological Characteristics of Soil

Biological Properties of Soil

• Soil acts as a habitat for many organisms, providing benefits such as adding nutrients and decomposing organic matter.
• Soil Biomass refers to the total amount of organic matter living in the soil.

Types of Soil Organisms

• Macro-organisms: e.g. earthworms, plants, rabbits
• Micro-organisms: e.g. bacteria, fungi

Functions of Soil Organisms

• Decompose organic matter to humus
• Add organic matter when they die
• Convert OM into humus (e.g. actinomycetes)
• Convert nitrogen into usable forms (e.g. fungi)
• Enhance water holding capacity, bind soil particles together, and help with disease resistance (e.g. mycorrhizal fungi)

The Rhizosphere

• The area around a plant root where the biological and chemical aspects of the soil are influenced by the root
• High levels of microorganisms are found in this area due to the compounds exiting the roots
• Symbiotic relationship between the plant and microorganisms

Earthworms (Lumbricus Terrestris)

• Decompose organic matter to humus and recycle nutrients
• Mix soil layers
• Improve drainage and aeration
• Improve fertility
• Improve soil structure
• High numbers of worms indicate ideal soil conditions

Conditions Required for Ideal Soil Conditions

• pH 6-8
• Moist soil
• High levels of organic matter
• Warm soil (above 10 degrees)
• Well aerated soil

Carbon Cycle

• Steps in the carbon cycle: photosynthesis, respiration, consumption, decay, and combustion
• Carbon takes multiple forms: CO2, carbohydrate, and carbonate ion
• Organic carbon: the organic matter within the soil is made up of 58% organic carbon
• Carbon footprint: the total amount of greenhouse gases produced directly and indirectly by the farmer
• Ways to reduce carbon footprint: planting more trees, reducing diesel usage, growing biofuels, not burning straw, and eco-tillage with minimum tillage

Nitrogen Cycle

• Nitrogen takes multiple forms: nitrogen gas, nitrate, ammonium, and nitrite
• Processes: nitrogen fixation, decomposition, nitrification, and denitrification
• Bacteria role in the nitrogen cycle: decomposes OM, converts nitrogen to nitrate, and converts nitrate to nitrogen gas
• Nitrogen fixation: nitrogen is converted into nitrate by rhizobium bacteria in the nodules of clover
• Symbiotic relationship between clover and rhizobium bacteria

Biological Properties of Soil

• Soil acts as a habitat for many organisms, providing benefits such as adding nutrients and decomposing organic matter.
• Soil Biomass refers to the total amount of organic matter living in the soil.

Types of Soil Organisms

• Macro-organisms: e.g. earthworms, plants, rabbits
• Micro-organisms: e.g. bacteria, fungi

Functions of Soil Organisms

• Decompose organic matter to humus
• Add organic matter when they die
• Convert OM into humus (e.g. actinomycetes)
• Convert nitrogen into usable forms (e.g. fungi)
• Enhance water holding capacity, bind soil particles together, and help with disease resistance (e.g. mycorrhizal fungi)

The Rhizosphere

• The area around a plant root where the biological and chemical aspects of the soil are influenced by the root
• High levels of microorganisms are found in this area due to the compounds exiting the roots
• Symbiotic relationship between the plant and microorganisms

Earthworms (Lumbricus Terrestris)

• Decompose organic matter to humus and recycle nutrients
• Mix soil layers
• Improve drainage and aeration
• Improve fertility
• Improve soil structure
• High numbers of worms indicate ideal soil conditions

Conditions Required for Ideal Soil Conditions

• pH 6-8
• Moist soil
• High levels of organic matter
• Warm soil (above 10 degrees)
• Well aerated soil

Carbon Cycle

• Steps in the carbon cycle: photosynthesis, respiration, consumption, decay, and combustion
• Carbon takes multiple forms: CO2, carbohydrate, and carbonate ion
• Organic carbon: the organic matter within the soil is made up of 58% organic carbon
• Carbon footprint: the total amount of greenhouse gases produced directly and indirectly by the farmer
• Ways to reduce carbon footprint: planting more trees, reducing diesel usage, growing biofuels, not burning straw, and eco-tillage with minimum tillage

Nitrogen Cycle

• Nitrogen takes multiple forms: nitrogen gas, nitrate, ammonium, and nitrite
• Processes: nitrogen fixation, decomposition, nitrification, and denitrification
• Bacteria role in the nitrogen cycle: decomposes OM, converts nitrogen to nitrate, and converts nitrate to nitrogen gas
• Nitrogen fixation: nitrogen is converted into nitrate by rhizobium bacteria in the nodules of clover
• Symbiotic relationship between clover and rhizobium bacteria

Biological Properties of Soil

• Soil acts as a habitat for many organisms, providing benefits such as added nutrients, decomposition of organic matter, and soil structure improvement.
• Soil biomass refers to the total amount of organic matter living in the soil.

Types of Soil Organisms

• Macro-organisms: earthworms, rabbits, and plants
• Micro-organisms: bacteria, fungi, and actinomycetes
• Bacteria: convert organic matter into humus, convert nitrogen into usable forms, and have a symbiotic relationship with plants
• Fungi: responsible for humification, have symbiotic relationships, and enhance water holding capacity, bind soil particles, and help with disease resistance

The Rhizosphere

• The area around a plant root where biological and chemical aspects of the soil are influenced by the root
• High levels of microorganisms are present in this area, feeding on compounds exiting the roots
• A symbiotic relationship exists between the bacteria, fungi, and plants, where both benefit from each other

Earthworms (Lumbricus Terrestris)

• Decompose organic matter to humus and recycle nutrients
• Mix soil layers, improve drainage and aeration, and fertility
• Improve soil structure
• High numbers of worms indicate ideal soil conditions

Conditions Required for Earthworms

• pH 6-8
• Moist soil
• High levels of organic matter
• Warm soil (above 10 degrees)
• Well-aerated soil

Carbon Cycle

• Steps in the carbon cycle: photosynthesis, respiration, consumption, decay, and combustion
• Plants take in CO2 from the atmosphere during photosynthesis and store it as a carbohydrate
• Carbon footprint: the total amount of greenhouse gases produced directly and indirectly by the farmer
• Farmers can reduce their carbon footprint by: planting more trees, reducing diesel usage, growing biofuels, not burning straw, and using eco-tillage and minimum tillage

Carbon Forms

• CO2
• Carbohydrate (CHO)
• Carbonate ion (CO32-)
• Organic carbon: makes up 58% of soil organic matter, stores carbon, and provides energy for the soil microbiome

Nitrogen Cycle

• Nitrogen takes multiple forms: N2, NO3-, NH4, and NO2-
• Processes: nitrogen fixation, decomposition, nitrification, and denitrification
• Nitrogen fixation: conversion of nitrogen gas into nitrate by rhizobium bacteria in clover nodules
• Symbiotic relationship: clover and rhizobium bacteria
• Decomposition: bacteria and fungi decompose dead matter and manure, forming ammonium
• Nitrification: conversion of ammonium to nitrate by Nitrosomas bacteria
• Denitrification: conversion of nitrate back to nitrogen gas by denitrifying bacteria under anaerobic conditions

This quiz explores the biological properties of soil, including the benefits of soil organisms, types of organisms, and their roles in decomposing organic matter and adding nutrients. It covers macro-organisms, micro-organisms, earthworms, bacteria, and fungi.