Last week I showed you boys picking up straw bales in the wheat field, but do you know what straw is? Or how it is different from hay? Before we begin, take a moment to create a hypothesis. That crazy word actually means “educated guess.” It is not a wild a crazy guess. For example, it would be a bit silly for you to guess that straw bales are moon dust and hay is fairy dust. Definitely not right. But you do know a few things you could use to base your guess on. You know it probably has to do with farming. Yes, that is broad, but it would certainly eliminate moon and fairy dust. You know straw has to do with a wheat field too. That narrows it down a lot. And you might know a few things I haven’t told you, like who eats hay or how your neighbor uses straw. Now, using that information try to create an educated guess about what hay and straw are.
Write it down in your science journal. Even if the answer is different from your guess you can still learn things from your guess.
Finished?
Great!
Straw is the stalk of the wheat. The combine can cut the wheat close to the ground, sucking in lots of stalk, separating it from the grain, and spitting in out in rows behind the combine. Then the stalks can be gathered up and pressed tight into bales by a machine like the one in the picture above. This machine wraps a plastic rope around the bales, holding them together.
Hay, on the other hand, is cut grass. And often not just any old grass, but certain types of grass, like alfalfa. Farmers cut the grass when it is a few feet tall with a special mower. The grass dries, becoming hay. A tool called a rake is pulled behind the tractor and the grass is moved into neat rows. Now the baler can scoop up the hay, just like it does straw, pressing it tight and wrapping it with twine.
Straw and Hay are also used for different purposes. Since animals eat grass all summer, farmers feed them hay in the winter. Using special grass like alfalfa helps keep cows, horses, sheep and goats healthy when the grass isn’t growing. Straw is often used on construction sites to keep the dirt from washing away and to keep the lawn wet as new grass grows. Have you seen it on the sides of a new highway project or in a newly constructed neighborhood? Straw is also often used a bedding for animals to sleep on and you might lay straw in the rows of your garden to keep weeds from growing.
Compare this answer with the guess you wrote down in your journal. How do they compare? Did you learn anything new?
Daddy's Tractor 