(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 &GreaterEqual;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 &GreaterEqual;1% guarantee Iron 25 percent of guarantee for <1% guarantee; 0.15 unit + 10 percent of guarantee for &GreaterEqual;1% guarantee Manganese 25 percent of guarantee for <1% guarantee; 0.15 unit + 10 percent of guarantee for &GreaterEqual;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 &GreaterEqual;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.