Soil Conservation: Protecting Our Earth's Foundation

Soil Conservation

• Soil is the foundation of life on Earth
• Soil erosion results from the wearing down and carrying away of soil
• Erosion occurs due to natural and human factors
• Soil conservation is the protection of soil against erosion
• Soil is conserved by:
  • Growing cover crops in plains
  • Making terraces on hills
  • Building embankments along river banks

Definitions

• Humus: Fertile topsoil consisting of dead, decaying plant and animal matter
• Soil: The upper layer of small particles on the Earth's surface where plants grow
• Embankments: Walls built to prevent floods or hold back water near river banks
• Cover crop: Crop grown to cover the field after harvesting and before the next crop
• Soil-profile: Cross-section through various layers of soil

Important Points About Soil

• 1 cm thick layer of soil takes more than a hundred years to form
• It takes 450 years for a plastic bag to degrade
• 1 kg of rich farmland soil contains:
  • 23 trillion bacteria
  • 400 million fungi
  • 50 million algae
  • 30 million protozoa
  • Thousands of worms and insects

Deserts and Soil Erosion

• In deserts, soil erosion occurs mainly due to wind
• Survival is entirely dependent on soil

Soil Protection and Cover Crops

• Terrace farming is effective for soil protection in hilly areas
• Peas, groundnut, and gram are grown as cover crops

Organic Material and Soil Health

• Recycling of organic material occurs in soil due to microorganisms that decompose organic matter
• Prioritizing soil health increases crop productivity, as fertile soil is rich in nutrients and has the capacity to hold water
• Soil stores large quantities of carbon

States of Matter

• Matter exists in three states: solid, liquid, and gas
• Heating or cooling causes changes in matter, which can be temporary or permanent
• Element: A substance made of a single type of atom (e.g., oxygen, chlorine, gold, hydrogen, carbon)
• Compound: A substance made of more than one type of atom (e.g., water, carbon dioxide, table salt, sugar)
• The properties of a compound differ from those of its constituent elements

Definitions of Matter States and Changes

• Molecule: Tiny unit that makes up matter
• Atom: The tiniest building block that joins to form molecules
• Physical Change: Rearranges molecules without altering internal structure (e.g., melting wax, tearing paper)
• Chemical Change: Results in forming new substances (e.g., rusting iron, milk souring)

Additional Info Regarding Matter

• Oxygen is an element that exists as oxygen gas and ozone gas, it is made of one type of atom
• Oxygen molecules have two oxygen atoms vs ozone has three
• Water expands when cooled instead of contracting
• Reactants are original substances that react in a chemical change and the new substances formed are the products
• Mixing salt in ice lowers the temperature which is useful in ice cream since it doesn't need electricity

States of Matter Properties

• Solids are more tightly packed than liquids
• atoms are the tiniest building box of matter
• Oxygen and carbon dioxide can dissolve in water
• Rusting iron is a chemical change
• Molecules of matter are always vibrating

More Definitions: Matter

• Dissolved solids separate as crystals
• Fish breathe in oxygen gas that is resolved in water
• Pure substances are elements
• Substances formed by 2+ different types of atoms are compounds
• Examples of elements include iron and copper
• Sodium hydroxide(NaOH) and Sodium Chloride(NaCl) are examples of compounds
• Molecules of of material are both the same

States of Matter Truths

• molecules of oxygen have three atoms (FALSE)
• gases dont have a fixed volume (TRUE)
• State of matter can be changed by heating or cooling (TRUE)
• Fizz in cola is actually oxygen gas (FALSE)
• Chemical changes are always accompanied by the formation of new products (TRUE)

Substances and Water Mixture

• Waters has the property to dissolve substance uniformly
• All matter is made of parts which are atoms

Force Energy and Simple Machines

• Applying force involves pushing or pulling
• Force can move stationary objects, stop moving objects, change the speed/direction/shape/size of an object
• Different Forces: muscular, gravitational, frictional, elastic, mechanical, and buoyant
• Simple machines can be grouped under levers, wedges, inclined planes, wheel and axles, pulleys and screws
• Simple machines make work easy which means that Energy is the ability to do work

Definitions simple machines

• Machine: A device that makes work easy
• Fulcrum: A fixed point around which a lever turns
• Lever: A strong iron rod which can turn about one fixed point
• Load: The weight to be lifted
• Effort: The force applied
• Torque: A force that tends to cause rotation

The Moon

• Moons are natural satellites of the planets, revolving around them
• Earth has one moon
• The moon lacks air, water, and an atmosphere
• Solar eclipse: when the moon is between the sun and Earth
• Lunar eclipse: when Earth is between the sun and the moon
• Humans first landed on the moon in 1969

Celestial Definitions

• Astronomy: The study of celestial bodies
• Waxing moon: The phase when it appears to get bigger
• Waning moon: The phase when it appears to get smaller
• Eclipse: Blocking of light from the sun or moon caused by the shadow of another celestial body

General Facts About The Moon

• Moon surface has very high mountains including Mount Liebnitz
• Apollo used heaters in gear + boots to stay warm in freezing temps
• Always see the same side of the moon, this is caused by the revolution around the earth
• moon is much closer as compared to the sun
• longest total lunar eclipse was 106 minutes

More Definitions

• shadow is formed when something opaque comes between the light
• opaque objects dont allow light
• Eclipses should never be seen with the naked eye
• earth spins like a top

Space Exploration Definitions

• EVA is extravehicular activity
• EVA stands for extravehicular activity
• Alexei Leonov was the first to do a space walk
• Ed White was the first American to do a space walk, in Gemini 4 Project
• Joystick works a controller like those found on a video game