Young Scientists' Terms

Molecules that join together to form proteins, the building blocks of all organisms.

Without oxygen as a part of the environment. The opposite of aerobic.

A chemical that weakens or stops bacteria, fungi, and other microorganisms from growing.

Dry, like a desert.

Mass of solid rock beneath the soil. Can be parent material if it is close enough to the surface to weather into soil.

A soil structure. Soil particles are arranged into shapes that resemble small cubes with sharp or rounded edges.

The smallest-sized soil particles. Often have plate-like shapes. Feels sticky when wet. Also refers to a soil texture that consists of at least 40% clay particles.

The five factors that influence what type of soil forms: climate, organisms, relief (landscape), parent material, and time.

A soil structure. Soil particles are arranged into tall vertical shapes or columns often with rounded tops.

The remains of plants and animals after they have decomposed. Can be used to fertilize soil and to improve its structure and ability to hold water.

The combination of two or more elements. For example, hydrogen and oxygen combine to make water.

To break down a compound into simpler compounds. Often accomplished with the help of micro-organisms.

A soil that has had a long time to form, such as most tropical soils. A mature soil.

Lacking in something important. A deficiency of nutrients in a plant, for example, can stunt its growth.

A state in which a plant or animal is not growing.

A scientist who studies interactions between organisms and their environment.

A horizon from which minerals, clay, and/or organic matter have been leached.

A protein that increases the rate of chemical reactions in an organism’s cells.

To wear away, or remove, rock or soil particles by water, ice, and/or gravity.

A semi-enclosed body of water with a source of fresh water and an outlet to the ocean.

The ability of a soil to supply essential nutrients to plants.

A substance added to soil that contains plant nutrients such as nitrogen, phosphorus, and potassium.

A kingdom of organisms distinct from animals and plants. Most fungi get their energy from decomposing plants and animals.

A soil structure. Soil particles are arranged into shapes that resemble granola. Has lots of pores.

Water that collects underground in the pore spaces of soil and rock. An important source of drinking water.

A layer of soil with properties that differ from the layers above or below it.

Organic matter such as highly decomposed leaves.

The removal of minerals and nutrients from a soil or a horizon as water passes through it.

A soil texture with moderate amounts of sand, silt, and clay, sometimes in nearly equal proportions. Good texture for farming and gardening.

Nutrients needed by organisms in relatively large quantities.

A soil that has no structure. Soil particles are completely stuck together.

Microscopic organisms, such as bacteria and fungi. Microbes represent the most abundant soil organisms.

A scientist who studies microscopic organisms, or microbes.

The inorganic particles in soils that weather from rocks.

Spots or blotches of color(s) in a soil that differ from that soil’s dominant color.

Macronutrient essential to living things like plant growth and building proteins. Often added to agricultural and garden soils.

Elements or compounds that nourish organisms. Essential for growth and reproduction.

Material derived from the decay of plants and animals. Always contains compounds of carbon and hydrogen.

Living things such as bacteria, fungi, plants, or animals.

The material from which a soil formed. Can be bedrock or materials carried and deposited by wind, water, glaciers, and/or gravity.

Partially decayed organic matter that accumulates in environments that stay wet.

The structural unit formed when soil particles (sand, silt, and clay) bind together.

A scientist who studies soils.

Plants that live for more than two years as opposed to annuals that grow each year from seeds or biennials that live for only two years.

A soil horizon, or layer, that remains frozen year round.

Macronutrient essential to all living things like flowers, fruits, seeds in plants, and the nervous system in animals. Often added to agricultural and garden soils.

The process by which plants, some bacteria, and some algae use sunlight to convert carbon dioxide and water into food and oxygen.

A soil structure. Soil particles are arranged into shapes that resemble flat plates.

The space between soil particles, which can be filled with water or air. A porous soil has lots of pores.

Macronutrient essential to all living things like water uptake and pest resistance in plants; muscles and blood circulation in animals. Often added to agricultural and garden soils.

A soil structure. Soil particles are arranged into shapes that resemble columns.

A term used to describe a soil that has the capacity to grow an abundance of crops.

The shape of the land surface created by features such as hills and valleys.

Water from precipitation or irrigation that does not soak into the soil but flows off the land and reaches streams and rivers.

The build-up of salts in soil. Often occurs in arid environments.

The largest-sized soil particles. Sand feels gritty. Also refers to a soil texture that consists of at least 85% sand particles.

Any particle of soil or rock that has been deposited by water, wind, glaciers, or gravity.

Waste that goes down a drain (such as those in bathrooms, kitchens, and laundry rooms) to a treatment plant or septic system.

Soil particles in between sand and clay in size. Silt feels like flour (smooth and velvety). Also refers to a soil texture that consists of at least 80% silt particles.

A soil that has no structure. Soil particles are not bound to each other in any way, such as beach sand.

A landscape, or surface, that is tilted or inclined.

Semi-solid material left behind after sewage has been processed in a treatment plant. May be used as a fertilizer in some instances.

Grass and the soil beneath it, held together by roots. Can be cut into blocks and used as a building material.

A mixture of minerals, organic matter, water, and air, which forms on the land surface. Can support the growth of plants.

A section of the soil that has been cut vertically to expose all its horizons, or layers.

The arrangement of soil particles into clusters, called peds, of various shapes that resemble balls, blocks, columns, or plates.

The relative proportions of sand, silt, and clay particles.

The soil horizon rich in minerals that eluviated, or leached down, from the horizons above it. Not present in all soils.

A group of cells in an organism that work together, such as muscles in an animal or the outer surface of leaves in a plant.

Mostly weathered minerals from parent material with a little organic matter added. The horizon that formed at the land surface.

To change from one thing into another or from one state into another, like a liquid into a gas.

The area of land and ocean that lies between 23.5° north and south of the equator.

An area in cold regions, such as in the arctic or on mountains, where the growing season is very short.

The ability of a plant to absorb water and nutrients.

To break down rocks and minerals at or near Earth’s surface into smaller particles and soil.

An area of land where the soil is saturated with water, such as a marsh, swamp, or bog.