soil

52問 • 2年前

問題一覧

is a dynamic natural body capable of supporting a vegetative cover.

Soil

Functions of Soil:

Climate Regulation, Flood Regulation, Habitat for Organisms, Foundation for Human Infrastructure, Provision of Construction Materials, Provision of Food, Fiber, and Fuel, Cultural Heritage, Nutrient Cycling, Carbon Sequestration, Water Purification and Soil Contaminant Reduction, Source of Pharmaceutical and Genetic Resources

Four Major Components of Soil:

Inorganic Materials, Organic Matter, Soil Air, Soil Water

Soils contain insoluble materials, soluble materials, and chemical constituents.

Inorganic Material

rock fragments and minerals that will not readily dissolve in water.

Insoluble Materials

the breakdown of underlying rocks.

Weathering

the process of adding nutrients or other constituents in order to meet the soil conditions that certain plants require.

Soil Fertilization

Sources of Chemical Constituents:

Breakdown of underlying rocks, Deposits of loose sediments, Minerals dissolves in water

the original source of soil water.

Precipitation

Capillary Water: Definition and Function

Water held in large pores., Serves as a stored water supply for plants.

Hydroscopic Water: Definition and Function

Water adheres to soil particles., Gives moisture to plants.

Gravitational Water: Definition and Function

Water drains through soil profile., Becomes part of the water table.

Water that percolates down through a soil, under the force of gravity.

Gravitational Water

Soil water found as a very thin film, invisible to the naked eye, that is bound to the surfaces of soil particles by strong electrical forces.

Hydroscopic Water

cementlike layer, like a clay hardpan which prevents the downward percolation of water.

Caliche

Depleting nutrients in the soil through flow of water.

Leaching

Downward removal of soil components by water.

Eluviation

Deposition by water in the subsoil.

Illuviation

characteristic layered changes with depth.

Stratification

Fine particles and substances dissolved from the upper soil are deposited in lower levels, which become dense and may be strongly colored by accumulated iron compounds.

Stratification

The decayed remains of plant and animal materials, partially transformed by bacterial action.

Humus

Difference in organic matter content of soil according to color:

Darker soil is richer with organic matter., Lighter soil contains very little organic matter.

Difference in organic matter content of soil according to location:

Moist have high level of organic matter., Dry have very thin organic matter., Flooded have no organic matter.

Most important soil properties:

Color, Texture, Structure, Acidity or Alkalinity, Capacity to hold and transmit water and air

Color of decomposed organic matter.

Black or Brown

Color indicates that iron has been leached out, leaving oxides of silicon and aluminum.

Light Gray or White

Color indicates a high proportion of calcium or salts.

Light Gray or White

Color indicates the presence of iron.

Red or Yellow

Soil Analysis: Instrument Used:

Colourimetric Determination, UV-Vis Spectrophotometer

refers to the particle sizes (or distribution of sizes) that make up a soil.

Soil Texture

Soil Texture:

Clay (<0.002mm), Silt (0.002 to 0.05), Sand (0.05 to 2.0), Rocks (>2.0mm)

Used to discern different classes of soil texture based on the plot of percentages for each soil grade.

Triangular Graph

“p” stands for ___ and the “H” stands for ___.

Potential, Hydrogen

One of the most important components of soil.

Soil pH Analysis: Instrument:

Acidic (0-6), Neutral (7), Basic (8-14), pH Meter

Soil acidity can generally be corrected by adding ___ to the soil.

Lime

Have purpose to increase pH of soil.

Liming

Ability to withstand rapid pH fluctuation.

Buffering

The vertical cross section of a soil from the surface down to the parent material.

Soil Profile

Soil Horizons:

O1 - deposit, Oa - decompose, A - humus, E - Eluviation, B - Illuviation, BC - rest, C - wheathering, R - rocks

2 Types of Parent Material:

Residual, Transported

___, a distinguished soil scientist, observed that soil development was a function of:

Hans Jenny, Climate, Organic Matter, Relief, Parent Material, Time

If weathered rock particles have accumulated in place— through the physical and chemical breakdown of bedrock directly beneath the soil.

Residual Parent Material

If the rock fragments that form a soil have been carried to the site and deposited by streams, waves, winds, gravity, or glaciers.

Transported Parent Material

There is less runoff and higher infiltration, more water is available for soil development and to support vegetation growth, so erosion is not as intense.

Gentler Slopes

Are generally better drained than gentler ones, and they are also subject to rapid runoff of surface water.

Steep Slopes

When soils have reached such a condition of equilibrium.

Mature Soils

When soils are still in the process of developing toward being in equilibrium with their environmental conditions.

Young Soils

Climate differences produce three primary soil-forming regimes:

Laterization, Podzolization, Calcification

A soil-forming regime that occurs in humid tropical and subtropical climates as a result of high temperatures and abundant precipitation.

Laterization

The collecting, treating, and disposing of solid material that is discarded because it has served its purpose or is no longer useful.

Solid-Waste Management

An act providing for an ecological solid waste management program, creating the necessary institutional mechanisms and incentives, declaring certain acts prohibited and providing penalties, appropriating funds therefore, and for other purposes.

Republic Act No. 9003

Pg 1. Radio-and-Television

Jian Estelle · 23問 · 2年前

Pg 1. Radio-and-Television