SOIL MAGIC.

Auckland Star, Volume LX, Issue 188, 10 August 1929, Page 3 (Supplement)

SOIL MAGIC.

ITS MYSTERIES EXPLAINED

What boy doesn't thrill at the magieian's art! And haven't you longed to perform tricks that would mystify your friends? Yet there is magic all about us, if we but know where to look for it and how to use it.

Take, for instance, the soil. Just plain, ordinary dirt is magic stuff, though you wouldn't think so to look at it. But to think it over, when you plant a seed it is apparently lifeless, yet, with warm weather, rain and sunshine, the seed gives forth life, and a new plant is born. Surely there must be some magic properties in soil or it couldn't induce and nourish life in this wav.

"Yet the trick is very simple," says the magician. "Watch closely and I will show you how it is done."

Maybe he does, but more likely he does not. .The hand is quicker than the eye, and deep down in your heart you know there.is nothing mysterious about the magician's tricks. Every trick is based on fundamental facts. Let's take a little simple equipment, like lamp chimneys, a couple of pails, sugar lumps, wicks, empty cans, a thermometer, a bottle or two, and some soil, and perform a little soil magic, and thereby learn some of the truths about dirt.

The Soil Lamp.—Whoever heard of a lamp with a wick made of dirt! Nevertheless, you can make sneb a lamp, and it will give a good light, too. Pill a small, narrow-necked bottle about one-third full of kerosene. Now fill the bottle to the top with pieces of dried dirt.. The kerpsene will rise slowly through the earth. When it has reached the top you can light it with a match.

What is going on? How does it work? The earth is porous. It is filled with air spaces. It is made of many particles, all touching one another. The oil creeps from one particle to another through these contact points. This phenomenon ie called "capillary attraction." The more contact points there are, the faster the liquid rises, therefore it rises faster through small particles than, large.

Moving Water Through a Wick.— Capillary attraction can. also be strikingly demonstrated with a lamp wick. Place two bottles side by side —one empty, the other with water in it. Wet a wick and put one end in the water and the other in the empty bottle. Slowly, but surely, the water will travel through the wick and drip into the empty bottle.

Mulch on Sugar Lump.—Sprinkle as much powdered sugar on top of a sugar lump as it will hold. Pour about 12 drops of red ink into a saucer, and place the lump in this little pool of ink. "Watch closely. The red ink rises, but how far? The sugar lump represents the soil; the powdered sugar is the mulch. Now you know what cultivation does for moisture in the ground, and how it helps to eave it from evaporating.

The Wet Blackboard. —Kub the blackboard with a wet eioth. Gradually the mark thus made disappears—fades

away. The board is dry again. Where has "the water gone? We say it has evaporated. That is what happens in soil. Water rises to the surface and evaporates. To preserve soil moisture, the wise fanner keeps a layer of dust on his land by cultivation. This is called "mulch."" In the previous experiment you saw the effect of such a mulch.

Loss of Soil "Water.—Pill two paib with about the same amount of moist soil. Jar the pails to compact the soil, w&igb each, and place them in a dry place for a week. In one pail stir the soil to a depth of about two inches every day. Do nothing to the other pailful of soil. At the end of the week •weigh again and determine which pail has lost the most moisture. Does the mulch save the soil moisture?

Capillary Attraction of Different Soils.—Take three lamp chimneys the same size. Over the end of each one tie a piece of cloth to serve as a bottom. Fill one chimney with dry sand,

the second with dry loam, and the third with dry clay. Pour about an inch of water into a shallow pan, and place the three chimneys with their contents in the water. A toothpiek, match, piece of cardboard, or some other little wedge should be placed under each chimney, bo that the water can get into the soil. Prom this experiment yon can determine through which kind of soil the water rises most rapidly.

Imitating a Cover Crop.—Tie a cloth over one end of :- lamp chimney, and fill part way with eand. 2s*ow put on a layer of straw. Add another layer of sand. Place your chimney and its contents in a pan of water, as in the previous experiment. How far does the water rise? "What is the effect of the straw layer? This experiment shows what happens to the soil moisture when a cover crop is turned under.

Burning Soil. —On a piece of sheet iron, or in a frying pan, place a handful of sand. Beside it put a handful of black dirt. Now put the iron and its piles of sand and dirt on the coals in the stove. After burning, what is left? The unburned material comes from rocks; that which has burned is rotted plante or leaves.

Soil Layers.—lnto a pail filled -with water put a handful each of sand, gravel., and loam: Now place the cover on the pail and shake well, then let it stand. Which falis to the bottom.

and which forms the second and third layers ? Soil Temperature.—How warm is dirt? An easy way to find out is to push a thermometer into the soil. You can take temperatures at different levels, depending on how deep you push the thermometer. Put several

kinds of soil —sand, loam, and gravelin a shallow dish, and plaee them in the sun. At various intervals take the temperature of each. "What kind of soil warms up the quickest? "Which is the slowest?

Imitating a Warm Eain. —Take two large empty baking powder cans and fill them within an inch of the top ■with a sandy soil. Punch a few holes in the bottom of one can. The soil in this can will be well drained, while the soil in the other will not be drained at all. Pour cold water on the undrained soil until water stands on the surface. Bring the soil in the drained can to the same temperature with cold, water. Now pour over each soil at least a half pint of warm water. Take temperature readings again. Tou have been imitating a warm rain. You should discover that a warm rain will warm a well-drained soil, while a poorly drained soil will remain cold after the same rain. This shows one reason for having fields well drained.—"Hoard's Dairyman."