230 likes | 355 Views
Bucket Chemistry 101. Bodie Pennisi , and Paul Thomas Extension Horticulture Specialists The University of Georgia. Bucket Chemistry. Fertilizer Problems Are Not That Bad !. The Way To Tackle Them Is …. Greenhouse Crops and Fertilizer Recommendations .
E N D
Bucket Chemistry 101 Bodie Pennisi, and Paul Thomas Extension Horticulture Specialists The University of Georgia
PROPORTIONER A device used in a fertigation system to control the rate of fertilizer applied through the system.
Fertilizer Injector or Proportioner Stock Fertilizer Tank 1 part stock solution Water line 100 parts of water Injector ratio 1 : 100 Irrigation line to plants
Fertilizer Injector or Proportioner Stock Tank Water line 1 part stock solution 5 gal 25 50 100 200 500 etc. x parts of water Injector ratios 2% 1% 0.5% 0.1% 1:50 = 1:100 = 1:200 = 1:500 = To get from ratios to percent: (1/50) x 100 = 2% To get from percent to ratios : 100/2%=1:50
Fertilizer recommendations for greenhouse crops are given as either ppm of a specific fertilizer nutrient or in pounds and ounces (weight basis) of a fertilizer formulation per 100 gallons of water Parts per million (ppm) One part of a substance into one million parts of another substance
Things You Need To Know To Solve ppm Problems: • Recommended fertilizer application rate. • Example: 8 ounces per 100 gal or 200 ppm nitrogen • 2. Fertilizer formulation and analysis. • Example: 20-10-20 • Injection ratio • Example: 1:100 • Size of stock tank in gallons • Example: 25 gallons
Weight Basis Example: A chrysanthemum grower gets a recommendation to apply 20-20-20 water-soluble formulation to a final concentration of 16 oz per 100 gallons of water. How much fertilizer should be mixed in a 25 gallon stock tank if an injector with a 1:30 injection ratio will be used?
Things You Need To Know To Solve This Problem: • Recommended fertilizer application rate. • 16 ounces per 100 gal • 2. Fertilizer formulation and analysis. • 20-20-20 • Injection ratio • 1:30 • Size of stock tank in gallons • 25 gallons
Solution Step 1: Adjust the rate for the stock tank size using the following equation: Equation 1 oz per 100 gal = oz fertilizer per stock tank 100 / Stock Tank Size (gal) 16.0 oz per 100 gal= 4.0 oz of 20-20-20 100 / 25 gal
Solution Step 2: Adjust the rate for the injection ratio: Equation 2 oz per gallon x injector ratio = oz per stock tank 4.0 oz per 25 gal x 30 = 120.0 oz per 25 gal tank!
Commercial Fertilizer (ppm) Example: A pansy grower gets a recommendation to apply 150 ppm nitrogen using 20-10-20 water-soluble formulation. How much fertilizer should be mixed in a 25 gallon stock tank if an injector with a 1:100 injection ratio will be used?
Things You Need To Know To Solve This Problem: • Recommended fertilizer application rate. • 150 ppm nitrogen • 2. Fertilizer formulation and analysis. • 20-10-20 • Injection ratio • 1:100 • Size of stock tank in gallons • 25 gallons
The Rule of 75 1 oz / 100 gal = 75 ppm • HOW DID WE GET THIS ? One ounce (28 grams) of any pure dry substance that will dissolve 100% in a volume of 100 gal equals 75 ppm 1 oz = 28 g or 28,000 mg 28,000 mg ÷ 379 L = 73.88 ppm ( 1 gal = 3.79 L 100 gal = 379 L )
Solution Step 1: Convert the ppm recommendation to a weight basis using the following equation: Equation 3 Recommended ppm x dilution factor = oz fertilizer/gal stock the N number (% ) of fertilizer X 75 150 ppm x 100 = 10.0 oz of 20-10-20 per gal stock 20 x 75 (final solution)
Solution Step 2: Use equation 1 to adjust for a stock tank size of 25 gallons: (oz per gal stock x (# gallons in stock tank) = Oz fertilizer per stock tank 10.0 oz x 25 gal tank = 250 oz of 20-10-20 in the tank
Solution Each bag is 25 lbs! Remember 25 lbs x 16 ox…the number of bags needed = 250 oz/ (16 oz X 25lbs ) or 0.62 bags! Step 4: Convert ounces to pounds and ounces where: 16 ounces = 1 pound (dry) 250.0 oz per 25 gal = 15 lbs 10 oz 20-10-20 16 oz/lb (. . . .in a 25 gallon stock tank) This will give you 150 ppm with a 1/100 ratio