Hort 4050
Calculation Homework Problems - Due November 14th
1.Your new boss suggest that you adjust your fertility program. He hands you a bag of 15-2-20 and tells you to apply a 250 ppm N solution to the pansies. He owns a Dositron injector currently set at 1/100. You are given a 5 gallon bucket that serves as the stock tank. Show me the calculations you need to perform to have the correct amount of fertilizer placed in the stock tank to deliver 250 ppm N.
2.Weeks later your boss tells you to change over to a “Poinsettia Finisher” fertilizer : 15-20-25. He wants a 300 ppm solution applied to the poinsettias. Given the same set-up as in problem #1, how much fertilizer is put into the stock tank?
3.Your boss puts up series of a modified cold frames for pansies in the middle of an open, field. The weather is cold, nasty and you’re late for work. He hands you a “Hozon” siphon proportioner that has a mixing ratio of 1 to 15. He shows you an old 20 gallon pig trough to be used for the stock tank. Then he tells you he wants a 75 ppm solution of calcium nitrate, 15-0-0-15, (N–P-K-Mg) applied to the pansies pronto! How much fertilizer do you put in the stock tank?
4.Mostly frozen, you decide your boss is a real jerk, you hate pig troughs and you want something better in a career than his pansy operation.....so you quit and land a good job in a big greenhouse firm in South Georgia. It’s warmer and you are happy. Your new boss over-hears you complaining about the old boss and he smiles really big! He pulls you aside and says “I have an easy fertilizing task for you with all modern equipment....no pig troughs here!” He shows you a 200 gallon steel stock tank and a brand new high quality “Smith” injector with a 1 to 300 ratio capability. He tells you to set the ratio at 1 to 200. He instructs you that he needs a 175 ppm solution of N applied to two acres of marigolds. Inquiring, you ask if you need to fill the stock tank all the way. He smiles really, really big and tells you that it will likely take two complete stock tanks to get through the day’s job. The application rate is 0 .25 gallons per sq ft. He comes back in a few minutes later and says “Let’s get the fertilizer bags!” He watches as you climb up and pull bags from a huge storage bin. Not wanting to appear primitive and backwards, how many 25 lb bags of 20-10-20 will you pull off the shelf to accommodate the job? How much dry fertilizer will you have left over that needs to be resealed in a plastic bag? Will it really take only two tanks? Check solubility on the bag...see Carl.
5. As you are pulling bags, the new owner confidently asks you.....How much actual phosphorus is in that 25 pound bag?