1. Hydrogen, Oxygen, Carbon, and Nitrogen

5.  The water cycle does what? ◦ Filters & provides fresh water. ◦ Without it, all organisms would rely on ground water only! – All surface water would be consumed or would evaporate & not be returned.  The carbon cycle does what? ◦ Provides input for photosynthesis and makes fossil fuels. ◦ Without it, plants would die – which would result in animal deaths due to lack of oxygen.  The nitrogen cycle does what? ◦ Provides nitrogen for plant growth (fertilizer) and makes up most of our atmosphere. ◦ Without it, our atmosphere would be highly combustible due to high oxygen content and plants may not be able to survive.

6.  Rounded to the nearest hundredth: ◦ Nitrogen = 78.09% ◦ Oxygen = 20.95% ◦ Argon = 0.93% ◦ Carbon Dioxide= 0.03% ◦ Total=100.00% Present in amounts less than 0.01% are: Hydrogen, Neon, Krypton, and Xenon Without Nitrogen, our atmosphere would be 95.62% Oxygen, 4.24% Argon, and 0.14% Carbon Dioxide!

7.  Exhaled air has approximately (varies by person) ◦ 78% Nitrogen – same as what was inhaled ◦ 18% Oxygen – 2.95% less than what was inhaled ◦ 4% Carbon Dioxide – 3.97% more than what was inhaled! This is what lets us perform mouth-to-mouth breathing! This also shows how little oxygen is consumed and how much carbon dioxide waste is produced with each breath.

8.  You’ve all learned about the water cycle since elementary – no need to really go in-depth on it again.  The carbon cycle we’ve already discussed when we covered photosynthesis!  The nitrogen cycle, we need to go a little more in-depth.

9.  Nitrogen compounds are used as fertilizers by plants. Without them, plants would not grow as well.

10.  All plants need nitrogen in order to be healthy!  Plants also need other nutrients in order to grow: Phosphorus, Potassium, Calcium, Magnesium, Sulfur, Boron, Copper, Iron, Chloride, Manganese, Molybdenum, and Zinc ◦ These are all minerals that animals also consume as part of their diet.  In order to ensure proper nutrient availability, farmers must fertilize their crops as nutrients are consumed by a particular plant.

11.  Some plants we consume are rich in certain nutrients. ◦ Example: Banana’s are rich in Potassium. This means that the soil is being depleted of Potassium. For more healthy bananas to be grown, we must replenish the Potassium!  We can replenish nutrients with chemical or natural fertilizers.

12.  We typically think of manure as something provided by livestock. Different animals produce manure with different nutrient qualities. ◦ Sheep – high in nitrogen and potash (potassium salt) ◦ Pig – low in nitrogen and potash ◦ Cattle – medium in nitrogen & potash, low in phosphorus ◦ Horse – same as cattle, but high in grass/weed seeds ◦ Chicken – high nitrogen and protein  Plant manure is created when we plow a crop into the soil for the purpose of fertilizing. ◦ Nutrient qualities will vary here too and will depend on the crop that is plowed-in.

13.  Some farmers choose to pay for chemical fertilizers so they can focus on just growing certain crops.  Some farmers choose to also raise livestock in order to have natural fertilizer for crops. However, this is also costly since you have to pay for the feeding and care of the livestock.  Some farmers choose to rotate and plow-in crops in order to ensure proper nutrient balance for upcoming crops.

14.  Chemical fertilizers are customized with certain percentages of nutrients to match what a farmer needs. However, to cover an entire crop can be very expensive!  Farmers found that keeping livestock of cattle and chickens provided the most nutrients for their crops. However, keeping livestock is still costly!  Rotating crops can provide a steady supply of produce and can resupply the soil with needed nutrients. However, a farmer must be willing to plant and harvest several different crops.

15.  Of all of these options, crop rotation seems to be the most mystifying. To help you understand you are going to complete an activity.  1 st - Read “Crop Rotation”  2 nd – Work with your table to correctly sort your crops into an acceptable rotation.  3 rd – Have your crop rotation checked.