Fla. Admin. Code R. 5E-1.027 (2026)
Investigational Allowances
(1) The investigational allowances are set as follows:
(a) Primary plant nutrients; investigational allowances.
Guaranteed Percent | Total Nitrogen Percent | Available Phosphate Percent (P2O5) | Soluble Potash Percent (K2O) |
04 or less | 0.49 | 0.67 | 0.41 |
05 | 0.51 | 0.67 | 0.43 |
06 | 0.52 | 0.67 | 0.47 |
07 | 0.54 | 0.68 | 0.53 |
08 | 0.55 | 0.68 | 0.60 |
09 | 0.57 | 0.68 | 0.65 |
10 | 0.58 | 0.69 | 0.70 |
12 | 0.61 | 0.69 | 0.79 |
14 | 0.63 | 0.70 | 0.87 |
16 | 0.67 | 0.70 | 0.94 |
18 | 0.70 | 0.71 | 1.01 |
20 | 0.73 | 0.72 | 1.08 |
22 | 0.75 | 0.72 | 1.15 |
24 | 0.78 | 0.73 | 1.21 |
26 | 0.81 | 0.73 | 1.27 |
28 | 0.83 | 0.74 | 1.33 |
30 | 0.86 | 0.75 | 1.39 |
32 | 0.88 | 0.76 | 1.44 |
34 | * | 0.79 | 1.46 |
36 | * | 0.83 | 1.49 |
38 | * | 0.86 | 1.51 |
40 | * | 0.90 | 1.54 |
42 | * | 0.93 | 1.56 |
44 | * | 0.96 | 1.58 |
46 | * | 1.00 | 1.61 |
48 | * | 1.03 | 1.63 |
50 | * | 1.07 | 1.66 |
52 | * | 1.10 | 1.68 |
54 | * | - | 1.70 |
56 | * | - | 1.73 |
58 | * | - | 1.75 |
60 | * | - | 1.78 |
62 | * | - | 1.80 |
*For N guarantees above 32%, the investigational allowance shall be 0.88; For TSP, the investigational allowance shall be 1.53%.
For guarantees not listed, calculate the appropriate value by interpolation.
(b) Nitrogen investigational allowances.
Nitrogen Breakdown | Investigational Allowances Percent |
Nitrate nitrogen | 0.40 |
Ammoniacal nitrogen | 0.40 |
Water soluble nitrogen or urea nitrogen | 0.40 |
Water insoluble nitrogen | 0.30 |
In no case may the investigational allowance exceed 50 percent of the amount guaranteed.
(c) Secondary and micro nutrients, total or soluble.
Element | Investigational Allowances Percent |
Calcium | 0.2 unit + 5 percent of guarantee |
Magnesium | 0.2 unit + 5 percent of guarantee |
Sulfur (free and combined) | 0.2 unit + 5 percent of guarantee |
Boron | 25 percent of guarantee for <1% guarantee; 0.15 unit + 10 percent of guarantee for ≥1% guarantee |
Cobalt | 0.0001 unit + 30 percent of guarantee |
Chlorine | 0.005 unit + 10 percent of guarantee |
Copper | 25 percent of guarantee for <1% guarantee; 0.15 unit + 10 percent of guarantee for ≥1% guarantee |
Iron | 25 percent of guarantee for <1% guarantee; 0.15 unit + 10 percent of guarantee for ≥1% guarantee |
Manganese | 25 percent of guarantee for <1% guarantee; 0.15 unit + 10 percent of guarantee for ≥1% guarantee |
Molybdenum | 0.0001 unit + 30 percent of guarantee |
Sodium | 0.005 unit + 10 percent of guarantee |
Zinc | 25 percent of guarantee for <1% guarantee; 0.15 unit + 10 percent of guarantee for ≥1% guarantee |
The maximum allowance for secondary and minor elements when calculated in accordance with this section is 1 unit (1 percent). In no case, however, may the investigational allowance exceed 50 percent of the amount guaranteed.
(d) Liming materials and gypsum.
Range Percent | Investigational Allowances Percent |
0-10 | 0.30 |
Over 10-25 | 0.40 |
Over 25 | 0.50 |
(e) Pesticides in fertilizer mixes. – An investigational allowance of 25 percent of the guarantee shall be allowed on all pesticides when added to custom blend fertilizers.
Rulemaking Authority 576.051, 576.061, 576.181 FS. Law Implemented 576.051, 576.061, 576.181 FS. History‒New 2-24-14, Amended 10-27-16.
Effective: 10/27/2016.