Cal. Code Regs. tit. 3, § 2317.5 – Investigational Allowances.

(a) A fertilizing material shall be deemed deficient if the analysis of any nutrient is below the guarantee by an amount exceeding the values in the following schedule:
1. (1) If the guaranteed percent is between listed values, the higher investigational allowance shall be applied. For example, a 21% N guarantee would have a 0.75% investigational allowance.
2. (2) In no case may the investigational allowance exceed 50 percent of the amount guaranteed.
3. (3) For Triple Super Phosphate (TSP), the investigational allowance for available phosphoric acid (P₂O₅) shall be 1.53%.
Primary Nutrients
Guarantee Percent
Total Nitrogen (N) Percent
Available Phosphoric Acid (P₂O₅) Percent
Soluble Potash (K₂O) Percent
4 or less
0.49
0.67
0.41
5
0.51
0.67
0.43
6
0.52
0.67
0.47
7
0.54
0.68
0.53
8
0.55
0.68
0.60
9
0.57
0.68
0.65
10
0.58
0.68
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
0.88
0.79
1.46
36
0.88
0.83
1.49
38
0.88
0.86
1.51
40
0.88
0.90
1.54
42
0.88
0.93
1.56
44
0.88
0.96
1.58
46
0.88
1.00
1.61
48
0.88
1.03
1.63
50
0.88
1.07
1.66
52
0.88
1.10
1.68
54
0.88
1.10
1.70
56
0.88
1.10
1.73
58
0.88
1.10
1.75
60
0.88
1.10
1.78
62
0.88
1.10
1.80
(b) Secondary and micronutrients shall be deemed deficient if the analysis of any element is below the guarantee by an amount exceeding the values calculated according to the following schedule:
1. (1) For low guarantees not represented by this table, an investigational allowance of 50 percent of the amount guaranteed will be applied.
2. (2) The investigational allowances are applied as follows:
  1. (A) For zinc guaranteed at 0.75 percent Zn, the investigational allowance is calculated as 0.005 + 0.1(0.75) = 0.08 percent. An analyzed value for zinc of 0.66 percent (0.75 - 0.08 = 0.67) or less would be declared deficient and in violation. An analyzed value for zinc of 0.67 percent or more is within the investigational allowance for a zinc guarantee of 0.75 percent Zn.
  2. (B) For zinc guaranteed at 36.0 percent Zn, the investigational allowance is calculated as 0.005 + 0.1 (36.0) = 3.605 percent. An analyzed value for zinc of 32.394 percent Zn or less would be declared deficient and in violation. An analyzed value for zinc of 32.395 percent (36.0 - 3.605 = 32.395) or more is within the investigational allowance for a 36.0 percent zinc guarantee.
Secondary and Micronutrients
Element
Investigational Allowance
Calcium
0.2 unit + 5% of guaranteed analysis
Magnesium
0.2 unit + 5% of guaranteed analysis
Sulfur
0.2 unit + 5% of guaranteed analysis
Boron
0.003 unit + 15% of guaranteed analysis
Cobalt
0.0001 unit + 30% of guaranteed analysis
Molybdenum
0.0001 unit + 30% of guaranteed analysis
Chlorine
0.005 unit + 10% of guaranteed analysis
Copper
0.005 unit + 10% of guaranteed analysis
Iron
0.005 unit + 10% of guaranteed analysis
Manganese
0.005 unit + 10% of guaranteed analysis
Sodium
0.005 unit + 10% of guaranteed analysis
Zinc
0.005 unit + 10% of guaranteed analysis
(c) Other guarantees or claims shall be deemed deficient if any ingredient or claim is below the guarantee by an amount exceeding the values in the following schedule:
1. (1) The investigational allowance for pH is applied as follows:
  1. (A) For organic input material liquid fish products, the National Organic Program states that the pH cannot be lowered below 3.5. 3.5 pH--3.5(3.14%) = 3.3901 pH. Any value below 3.3901 pH would be in violation of the National Organic Program rule (7 CFR 205.601(j)(8)). Any value between 3.3901 to 3.4999 is within investigational allowance.
Other Ingredient Guarantees or Claims
Ingredient or Claim
Investigational Allowance
Humic Acid
10% of guarantee
Soluble Silicon
10% of guarantee
Calcium Sulfate Dihydrate (CaSO₄ • 2H₂0)
5% of guaranteed analysis
Gypsum Equivalent
5% of guaranteed analysis
Calcium Carbonate Equivalent
5% of guaranteed analysis
Lime Score
5% of guarantee
Vitamin B-1 (thiamine hydrochloride)
30% of guarantee
Total Phosphoric Acid (P₂O₅)
Refer to 3 CCR Section 2317.5(a), Available Phosphoric Acid (P₂O₅). The same investigational allowances apply.
pH
pH 3.14% of required
National Organic Program value (3.5 pH) (only required for organic input material liquid fish products)

Note: Authority cited: Sections 407, 14502, 14645 and 14647, Food and Agricultural Code. Reference: Sections 14645 and 14646, Food and Agricultural Code.

History

1. New section filed 5-4-2020; operative 7-1-2020 (Register 2020, No. 19).

2. Amendment of subsections (b) and (c)-(c)(1) filed 9-29-2022; operative 1-1-2023 (Register 2022, No. 39).

3. Amendment of subsection (b)(2)(B) filed 11-14-2025; operative 11-14-2025 pursuant to Government Code section 11343.4(b)(3) (Register 2025, No. 46).