Category Archives: AR

Nitrogen Cycle Montessori Style

The Montessori Elementary child is presented with a number of lessons about plants.  We have previously discussed the first 2 lessons of plants: 1.  The Four Greek Elements and 2. What Nutrition Plants Need.  These serve as an introduction to the idea of chemistry to the Elementary child.  We’ve discussed the historical practice of leaving ground fallow and the modern practices of fertilization (with the example of cotton in the post Civil War south as the prime example).  The third of these lessons is a discussion of Nitrogen and the Nitrogen Cycle.  There are diagrams of each of the lessons that were created after Dr. Montessori did by a number of her followers.  These diagrams lack the elegance for which Montessori works are known.  Perhaps the most unsettling of the diagrams is the Nitrogen Cycle’s.  So, Mrs. W and I worked out a hands-on work.  We are open for suggestions.


  1. Chart 2 of “Plant nutrients”.
  2. Jar of air.
  3. Soybeans, peanuts or other legumes
  4. Chart 3 – nitrogen cycle in felt parts.
  5. 4 boxes with the parts.
    1. “Free Nitrogen”
      1. 10 tickets labled “N”
      2. 10 tickets labeled O
      3. 10 tickets labeled H
    2. “Nitrification box 1 – atmosphere”
      1. Cloud in grey felt
      2. Rain
      3. Lightening with two branches
    3. “Nitrification box 2 – terrestrial”
      1. legume stalk and roots
      2. legume leaves
      3. nitrogen fixing bacteria
      4. deer
      5. poop x 2
      6. earthworms
    4. “Denitrification”
      1. green leaves
      2. brown leaves
      3. bones for deer
      4. denitrification bacteria
      5. fungi – mycelia and mushroom
  6. Jar with soil.

Nitrogen Cycle Presentation:

Lay out the underlayment and place underground water table, tree, sun and clouds in their places.  Open “Free Nitrogen” box.

Plants, like all organisms, require a certain number of chemical elements for growth.

The story of one of these, nitrogen, is an interesting one. Nitrogen is especially important because proteins are rich in it, and they carry out a lot of the work in the cells.

Take a deep breath.  Slowly breath it out.  Hold the glass of air up.

Even though 78% of the air we breathe is nitrogen, plants and animals can’t use the free nitrogen.

Lay out most of the Free Nitrogen cards in the atmosphere.

We breathe it back out.

Show Chart 2.  Invite the children to recall the lesson and name the elements.

And out of the 12 or so elements that a plant must obtain from the soil, only nitrogen can’t be obtained directly.  It must first be fixed – that is, combined with other elements usually hydrogen or oxygen.  This happens in a two main ways.  When nitrogen is fixed, it is called “Nitrification.”

Lay out the rest of the Free Nitrogen cards in the soil.

Open “Nitrification box 1 – atmosphere” box.

The first way nitrogen is “fixed” is in the atmosphere. The catch is that nitrogen will only bond with its favorite elements when there is high temperature and pressure.  Where in the atmosphere will you have really high temperatures and lots of pressure?

In lightening bolts!

Set out the cloud and place the H2O tickets in the cloud. (4 H2Os)

Lay out rain.  Move an H2O into the stream of rain.

When the lightening bolts strike the nitrogen bonds with oxygen making Nitric oxide.

Lay down the lightening bolt.  Move the first H2O near one branch of the lightening bolt and bring a N over to the H2O, split it apart and allow the H2s out into the atmosphere.  Join the N with the O.

Move the second and third H2Os near the second branch of the lightening bolt and bring over a N, split it apart and allow the H2s out into the atmosphere.  Join the NO2 together.

When the NO2’s fuse this is called nitrogen dioxide.  The Nitric oxide falls to the ground with the rain.  However, not all of the nitrogen dioxide falls directly to the ground.  It bumps into some of the H2O’s.  It then fuses and forms nitric acid.

Move the NO2s with waters and arrange them into nitric acid.  Make sure all the nitric oxide, nitrogen dioxide, and nitric acid move into the soil.

These three types of fixed nitrogen that are made in the atmosphere are may be used by plants.  This is three ways Nitrification takes place in the atmosphere.

Move one of the nitrogen dioxides into the trunk of the tree through the roots.

Open “Nitrification box 2 – terrestrial” box.

In temperate soils, another types of fixation takes place in the roots of some plants.

Ask the children to name some legumes. Share the soybeans or peanuts.  While the children chew, lay out the legume plant.

As these plants grow, their root hairs send out certain chemicals that attract root bacterias.  When the bacteria touches the root hairs two things might happen.  1. if it is not the right type of bacteria the root protects itself for it.  But, if it is the correct type of bacteria, it is held there,

Lay out the bacteria in the soil and move them to the roots of the legume.

and a kind of tube grows from each bacteria into the cells of the tiny root hairs.  These bacteria enter into the cells and reproduce causing a swelling called a “nodule” on the root.

Move the bacteria onto the roots.

This is not an invasion that will hurt the plant.  The bacteria and the plant are working together.  Do you know the word that is made from the Greek word sym meaning together and the word bios meaning life?

The plant provides energy in the form of ATP and the bacteria bring an enzyme that takes the fixed nitrogen and combines it with hydrogen and that makes ammonia!

Move the NO2 to the plant’s roots and combine it with Hs from water to make NH3

The ammonia is quickly converted into NO2 and NO3.  Plants use these as fuel for growth.  It is incorporated into many amino acids when are used to make proteins.

Make the NO2 and NO3.

The Oxygen from the water is not wasted but used as part of the process and then released.  Nitrogen is stored in the leaves, fruit, and roots of the legumes  and remember that the fixed nitrogen that was made by the lightening can be used by other plants.  This is quite a bit of nitrogen hanging out in plants.  But man needs nitrogen, too.  How do we get nitrogen to help us grow?

Say a person, or a horse, or a deer comes along and sees some tasty soybeans or pulls up a peanut plant and finds tasty peanuts,  what do they do?       Ahhhhh.

Lay down the deer with him “eating” the legume.

Yes they eat it.  Now the fixed nitrogens are inside the deer.  I wonder how they might come out?

Lay down the feces.  The first at the anus of the animal and the second on the ground where it would fall.  Lay down the earth worms.

One way is for the animal to excrete waste.  The animal might be a tiny earthworm or a giant whale.  It still extracts what it can from its food; it can’t take all of the nutrients and some pass into the feces to be excreted from the body.

Open the “Denitrification” box.

We now begin the process of “Denitrification” – of breaking apart the fixed nitrogen into single nitrogen atoms to be used again.

Can you think of another way that the nitrogen trapped in a living thing can be returned to its denitrified state?

This may be difficult for the children to think through.  Give a second or two and lay the deer down so his main body is below the soil line.  Add the bones to the body.

What about the plants?  How does the trapped nitrogen leave the plants?

They will get it and will say that the trees and plants die.

Yes they do die,  but some trees live a very long time.  How about their leaves?  On most trees, they live only one year and then fall off.

Put the green leaves falling and the brown leaves on the ground near the deer.

What creatures have been given the special job of decomposition?

Bring out the mycelia and the mushroom,  bring out the bacteria, move the earthworms over.

Take the nitrogen and oxygen in the deer and break it apart and return it to the atmosphere.

Take the nitric acid in the tree and break it apart and return it to the air.  Put water back into the clouds and generally reset the cycle.

This important job of denitrification takes death and turns it back into what brings life and growth.  The cycle may begin again.

Touch the clouds and walk through the cycle again using the major terms.

Now that you have had this lesson you may do this work.  You must be very careful with so many ways and times that nitrogen fixes, you must be observant and thoughtful to cause the correct nitrification and denitrification at the correct time in the cycle.


  1. Volcanoes,  power plants, and cars also can fix Nitrogen.
  2. A byproduct of denitrification is N2O or nitrous oxide, “laughing gas” and is considered a greenhouse gas.
  3. The oceans have their own nitrogen cycle which involves blue-green algae and other bacterias without having a symbiotic relationship with plants.
  4. Fertilizers and the Haber Process is its own topic and worth research by an upper el student.


Filed under AR, AV, Biology, BW, Chemistry, DW, JV, Science, Students

Here we go . . .

At 8 yesterday evening, the R and W families loaded up into the mini-van for a night drive to Florida and the launch of the shuttle.

Their plan was to meet up with the NASA shuttle in Titusville, FL at 3:30am (Yes AM!).

UPDATE:  Yey!  There was lift off.

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Filed under AR, BR, BW, DW, Going outs (Field Trips), LR

AR – the over achiever

In the recent project presentation, AR and BW had many topics to cover and the imaginary island project is not normally assigned to a first or second year ever because there are many, many topics to synthesize in the creation of a functional imaginary island.

AR and BW were to mainly work on the secondary land and water forms and where in the scheme of things these forms can be found.

Upon completion of the book of land and water forms, AR decided that she wanted to create an imaginary island, too.  She chose an island located off the coast of Peru. She researched Peru without thinking about the biomes found in Peru.  When she finally realized this, she dug deep and discovered some remarkable things that changed her island completely.  It wasn’t lush and tropical; it was a desert!  It was covered in bat and bird poop!

She did a remarkable job working through her problems and adjusting to new findings.

AR redid her bamboo tropical house; now, a cave covered in poop!

AR created a wool and stick doll that is given to the children to play with but has talisman qualities.

Her religion is based off of the birds who migrate to her island. This is a gourd mask.

After it was all said and done, AR blew off a bit of steam on JV's bamboo flute.

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Filed under AR, Art, Biology, Geography and World Studies, Geology, Oceans and their creatures, Projects, Science, Tides and Waves

From one old city to another

The W and R families are in FL to watch the Space Shuttle Endeavor blast off.

On their way down 95 they took a lunch break in St. Augustine.  They toured the fort and drove through the town.

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Filed under American History, AR, BW, DW, Geography and World Studies, Going outs (Field Trips), LR, Montessori

Making Bricks in Liberty Square

The kids made brick molds and then filled them with SC upland clay and then sanded them.  We are letting them air dry for two weeks and then we are going to bake them in our oven.

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Filed under American History, AR, AV, BR, BW, Chemistry, Construction Skills, DW, Geography and World Studies, Geology, Going outs (Field Trips), JV, Practical Life - Elementary, Science, US Civil War

Photos from Thursday

The kids are working on the practical things that the cultures they are studying would have created.  Oh yeah – fractions, too; it is Lent.

AV and BW are working with addition and simplification of fractions.

BR cutting azalea branches to make a neolithic indian structure

Mrs. EV shows AR how to weave palm frond mats for her home's walls.

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Filed under "Coming of Man", AR, BR, BW, Geography and World Studies, Projects

Photos from our Overnight to Greenville

We’ve returned from our trip to Greenville, SC. Here are a few photos from the goings on.  We forgot to take photos before the opera.  We enjoyed it.  The consensus was that Faust was not as good as Samson et Delilah.

The little guys went with Ms. ER to Restaurante Bergamo They tried caprese.  It was a little sketchy for the kids. They knew what tomatoes were and were nervous about eating them with balsamic vinegar and mozzarella. It wasn’t their favorite, but it was OK.  The mussels they had next were their favorite. Then they tried shrimp alfredo.  Alfredo sauce is a winner. Their desserts were wonderful.  BW exclaimed the next day, “If I could have licked the plate, I wanted to….The key lime pie was that good!”  They had worked so hard to get the proper table manners down.  BW held the doors and helped seat the ladies. They handled the mussel fork and the accompanying juices very well.  Being able to move from the primitive skills camp to the finest tables that a city might offer, is a skill set for which a Montessori child must strive.

They found out that new foods are worth the try.

The next morning as AV and JV slept in, every one else headed to Greenville Children’sMuseum.

When they arrived, the car building and racing section was a MESSSSSSS! Before they began building and racing their cars, they had to organize the materials! Oh yes!

Ms. JW's attack on the wind tunnel.

AV and LR in the middle of the Falls.

Ms. ER brought LR and AR to meet up with JV and AV who had picnicked at the Falls Park.  The kids found a snake, hopped rocks, and looked at the work of water all around them.

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Filed under AR, AV, BR, BW, DW, Erosion, Geology, Going outs (Field Trips), JV, LR, Practical Life - Elementary, Science