|Plants & Human Affairs (BIOL106) - Stephen G. Saupe, Ph.D.; Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321; email@example.com; http://www.employees.csbsju.edu/ssaupe|
Comparing Cost of Fertilizers based on Nitrogen
Nitrogen is the most important element � because it is required in the greatest amount (1-4%) Since it is a major consideration, calculate cost. To calculate the cost, use the formula:
Nitrogen cost ($/kg) = cost of fertilizer ($) x 1/ %N x 1/pack mass (kg fertilizer)
The first one is done for you. Complete the remainder of the table.
|N-P-K||Pkg Price ($)||Pkg Wt (kg)||Nitrogen cost ($/kg)|
|Schultz Instant Liquid||L||10-15-10||4.99||0.397|
S= soluble, L = liquid O = organic C = controlled
This exercise is adapted from Hershey, D (1990) Sleuthing the nutrients that make your houseplants grow. Science Activities 27: 17 � 20.
Last updated: 01/11/2005 / � Copyright by SG Saupe / URL:http://www.employees.csbsju.edu/ssaupe/index.html