Erosion and Soil

hi I'm Jared welcome to fun science demos the big idea today is erosion and how water has the power to shape our land but we don't want the water to shape our land too much because we need that soil to grow plants we use those plants for food and animals use those plants for food so what you see in front of me are three different types of land this first type is just bare soil it's just soil this next type has dead leaves on top and the third type has plants growing in the soil this may not look too exciting right now but when it rains that water has the power to change the land and we're gonna make it rain to see what that water's going to do to our land so we cut the top off of three plastic bottles and we put the same soil in each of those three bottles all of these bottles have the same soil we covered this soil with dead leaves and we grew some plants in this bottle we've also used other plastic bottles to catch the water that's going to come out of these when we pour it into the bottle we want to pour water into each bottle and see what happens does that water have the power to change the land what do you think's going to happen when we pour water into this bottle and it comes out into the cup will it be any different from the water we pour into this bottle as it comes into the cup and will this one be any different when we pour water into this bottle and it comes out into this Cup so I'm going to slowly pour water in you're gonna see the water level rise and we'll see what happens with our soil we'll keep it coming and now it's coming out take look at the bottle we used to catch the water what do you notice it's cloudy so why is it cloudy that's because all the dirt and the soil from our bottle was washed into the cup the water had the power to actually take the dirt and the soil with it out of the bottle and into the cup the water moved the soil it shaped the soil so now I'm gonna pour about the same amount of water into the next bottle what do you think's gonna happen the water that we catch will it be just as dirty will be less dirty well we even be able to see difference well let's pour the water and find out here we go so I'm pouring the water in making it rain adding water to our bottle can see the leaves floating to the top do we have any overflow yes we do stop the rain and see what we have so we've zoomed in so you can compare the two this one has lot of the soil in the in the container this one just has little bit of the particles little bit of the soil in that water so why do you think this container is little bit cleaner well what's different between the two well this one had leaves dead leaves on top and think most of these dead leaves helped protect the soil underneath from moving with the water so what do you think is gonna happen with our third container we have plants growing in the soil what's gonna happen when you add water and make it rain in this container alright here we go let's add the water about the same amount pouring the water in what do you think's going to happen here add little bit more it's coming out we're gonna stop pouring and see if we can compare what we see coming out the water coming out of this container looks whole lot cleaner than this one and little bit cleaner than this one so the question is why why is this water cleaner poured about the same amount of water in each container of soil but this one looks really clean well to answer the question why we have to zoom in and take closer look at what's really going on here so now we're all set to take closer look at why the water coming out of this bottle was so clean and clear compared to the others to do that I'm gonna actually lift these plants out of this bottle and let's see what happens well what notice right away is what comes along with all of the plants well the soil is actually coming out too when flip it over think you'll be able to see why so we've zoomed in so we can see what's going on here why is this soil staying together why is it staying in place well you can see the roots from our plants grew into the soil and almost like little fingers those roots are holding the soil together so when it rains the roots keep the soil from washing away the roots of the plant that's what keeps the water from eroding the soil besides holding the soil together and in place roots do another amazing thing to show you that I'm going to squeeze this and want you to watch what happens where did all that water come from well that came from when we made it rain on our soil the roots of the plants helped hold that water in plant roots actually go deep into the soil and this model is gonna help us see how deep they can go we're gonna zoom in and see if we can see those really tiny plant roots that we have growing in our soil we've zoomed it now so you can see these tiny roots in action I'm going to point them out and they actually extend from the plant all the way down to the bottom of our soil I'll point out some of the bigger ones they grow down into the soil and think about what they're doing they're holding that soil in place all of these tiny roots getting nutrients from the soil but they're also helping the soil out plants do an amazing job at keeping erosion from washing away too much soil we need that soil we depend on that soil to grow plants and animals depend on that soil to grow plants you want to learn more about plants and soil and erosion check out our links in the video description science is so cool and sometimes it's dirty thanks for watching