First horticulture math problems.
show all work @mastergrowers
I want to compare the cost of my nitrogen source in my fertilizer. Same math for other elements.
PETERS EXCEL 15-5-15 CAL-MAG FERTILIZER, 25# BAG @$48
vs. PETERS 21-7-7 FERTILIZER, 25# BAG, ACID SPECIAL $43
What is the cost of pure nitrogen per pound of each formulation?
Which fertilizer cost the least?
You can do the same calculation for N-P-K.
The formulation of the peters Cal Mag is
Total Nitrogen (N)… | 15% | |
---|---|---|
1.1% Ammoniacal Nitrogen | ||
11.8% Nitrate Nitrogen | ||
2.1% Urea Nitrogen | ||
Available Phosphate (P2O5)… | 5% | |
Soluble Potash (K2O)… | 15% | |
Calcium (Ca)… | 5% | |
Magnesium (Mg)… | 2% | |
2% Water Soluble Magnesium (Mg) | ||
Boron (B)… | 0.0187% | |
Copper (Cu)… | 0.0187% | |
0.0187% Chelated Copper (Cu) | ||
Iron (Fe)… | 0.075% | |
0.075% Chelated Iron (Fe) | ||
Manganese (Mn)… | 0.0375% | |
0.0375% Chelated Manganese (Mn) | ||
Molybdenum (Mo)… | 0.0075% | |
Zinc (Zn)… | 0.0375% | |
0.0375% Water Soluble Zinc (Zn) |
The formulation of peters acid special
Total Nitrogen (N)… | 21% | |
---|---|---|
10.4% Ammoniacal Nitrogen |
10.6% Urea Nitrogen||
|Available Phosphate (P2O5)…||7%|
|Soluble Potash (K2O)…||7%|
|Magnesium (Mg)…||0.6%|
||0.6% Water Soluble Magnesium (Mg)||
||||
|Sulfur (S)…||13%|
||13% Combined Sulfur(S)||
|Boron (B)…||0.0262%|
|Copper (Cu)…||0.0262%|
||0.0262% Chelated Copper (Cu)||
|Iron (Fe)…||0.15%|
||0.15% Chelated Iron (Fe)||
|Manganese (Mn)…||0.05%|
||0.05% Chelated Manganese (Mn)||
|Molybdenum (Mo)…||0.01%|
|Zinc (Zn)…||0.05%|
||0.05% Chelated Zinc (Zn)||
Extra credit do the same calculation on
Peters 15-16-17 Peat-Lite. $42 for a 25# bag.
What is the percentage by weight of each form of nitrogen?
Additional credit what is the minimum soil temperature for conversion of urea to nitrate? Not really a math problem but a grower problem.
———————————————————————————
Calculate 400 ppm of nitrogen for each of the above products. 1 to 1 ratio to start with.
What is the most cost effective source of nitrate from the above fertilizers.
Extra credit, what is the maximum solubility of the concentration for each formulation. This is tricky.
Extra, extra credit. For field production only what is cost per pound of nitrogen for your local formulation of Ag grade balanced fertilizer eg. 1-1-1, 13-13-13 or 19-19-19. Each local will have its own Ag grade balanced fertilizer. And the cost varies dramatically across the country by location.
@Growernick @nick and @Hunter do we have GN swag for the winner?
Last call will close and provide answer next week Friday December 21 at 7 PM PSDT