1. (a) A commercial fertilizer, or any individual element contained therein, shall be deemed deficient if the analysis of nutrient is below the guarantee by an amount exceeding the values in the schedule below. Such guaranteed analysis shall be conducted in accordance with the recommended Association of Official Analytical Chemists (A.O.A.C.) procedures for obtaining samples and sample preparation. Such procedures are described in Official Methods of Analysis of the Association of Official Analytical Chemists, 11th edition, 1970, and in succeeding issues of the Journal of the Association of Official Analytical Chemists. Replicate data shall be evaluated by following the instructions listed in the Journal of the Association of Official Analytical Chemists, vol. 59, no. 5, pg. 935, table 19, October 1966. GuaranteePercentNitrogenPercentAvailable PhosphoricAcid, PercentPotashPercent040.490.670.41050.510.670.43060.520.670.47070.540.680.53080.550.680.60090.570.680.65100.580.690.70120.610.690.79140.630.700.87160.670.700.94180.700.711.01200.730.721.08220.750.721.15240.780.731.21260.810.731.27280.830.741.33300.860.751.39320.880.761.44
2. (b) Secondary and minor elements shall be deemed deficient if any element is below the guarantee by an amount exceeding the values in the table below. The maximum allowable deviation of the values listed in such tables shall be one unit (1%). ElementAllowable DeficiencyCalcium0.2 unit + 5% of guaranteeMagnesium0.2 unit + 5% of guaranteeSulfur0.2 unit + 5% of guaranteeBoron0.003 unit + 15% of guaranteeCobalt0.0001 unit + 30% of guaranteeMolybdenum0.0001 unit + 30% of guaranteeChlorine0.005 unit + 10% of guaranteeCopper0.005 unit + 10% of guaranteeIron0.005 unit + 10% of guaranteeManganese0.005 unit + 10% of guaranteeSodium0.005 unit + 10% of guaranteeZinc0.005 unit + 10% of guarantee
3. (c) Method of determining investigational allowances. A minimum of two (2) values shall be averaged in order to determine that the minimum guarantee has been met. If more than two (2) values are obtained, all significant values shall be averaged. Each value may be "rounded" to one decimal place for easy recording, but each value shall be carried to two (2) decimal places in order to apply such established averages to the preceding table. If the requisite guarantee is not listed in such table, the necessary appropriate value shall be calculated by interpolation.
4. (d) Sampling. Wherever applicable, all sampling equipment used and procedures employed shal be those adopted by the Association of Official Analytical Chemists.

(Effective August 9, 1979)