xt7gms3jz83d https://exploreuk.uky.edu/dips/xt7gms3jz83d/data/mets.xml Kentucky Agricultural Experiment Station. 1960 journals 164 English Lexington. Contact the Special Collections Research Center for information regarding rights and use of this collection. Kentucky Agricultural Experiment Station Regulatory series, bulletin. n.164 text Regulatory series, bulletin. n.164 1960 2014 true xt7gms3jz83d section xt7gms3jz83d Regulatory Bulletin l64 ANALYSES OF OFFICIAL FERTILIZER SAMPLES I by the FEED AND FERTILIZER DEPARTMENT KENTUCKY AGRICULTURAL EXPERIMENT STATION > SEMI-ANNUAL REPORT ‘ SPRING SEASON ]ANUARY-JUNE, 1960 1 Or e} lk ¤: Z ·— A “$‘ 74"E E A A QJQQ /865* UNIVERSITY OF KENTUCKY, LEXINGTON CONTENTS Page Explanation of Tables ........................................................... 4 Companies Represented by Samples Reported in this Bulletin ...................... 5 Explanation of "standing of Manufacturers" ...................................... 7 Tonnage of Fertilizer Sold ...................................................... 7 Standing of Manufacturers ...... . ................................................ 8 Variation in Fertilizer Analyses ................................................ 10 Why A Concern For Variability? .................................................. 10 Reporting the Analyses of Fertilizer ...... . ..................................... ll ‘ Average Analysis, A Measure ..................................................... ll Measuring Variability ........................................................... ll "Wild" Samples ............................... . ................................. . 12 Note on Methods of Computation Used ............................................. 12 Infomation Given In Tables ..................................................... 13 Average Percentage of Guarantee and Coefficient of Variation for all Samples by Fertilizer Manufacturers .............................. 14 Explanation of References in Table l .................. . ......................... 16 Table l, - Analyses of Inspection Samples of Mixed Fertilizer, Superphosphate, and Fertilizer Salts ....................................... 17 Table 2, - Analyses of Inspection Samples of Rock Phosphate, Basic Slag, Fused Trlcalcium Phosphate, January-June, 1960 ..................... .. 124 V Table 3, — Analyses of Inspection Samples of Bone Meal, Dried Manures, etc., January-June, 1960 ............................. . ............ 12/+ Table 4, - Results of analyses of Fertilizer Samples in which the guarantee for Sulfate of Potash was not met ................................ 125 Table 5, - Results of analyses of Boron in Fertilizers Reported in Table l ................................................................. 128 Table 6, - Results of analyses of Insecticides contained in Fertilizers shown in Table 1 ............................ . .................. 130 a . FEED AND FERTILIZER DEPARTMENT ’ KENTUCKY AGRICULTURAL EXPERDIENT STATION Bruce Poundstone, Head of Department Robert Mathews, Asst. Adm. & Chief Inspector Guy P. Zickefoose, Auditor-Inspector *David M. Daugherty, Registration Inspector W. J. Huffman, Acting Registration Inspector FIELD INSPECTORS · M. M. Davis Neville Hulette Noel J. Howard O. R. Wheeler W. M. Routt ` LABORATORY STAFF Harry R. Allen J. A. Shrader Lelah Gault Valva Midkiff John H. Ellis Norma Holbrook J. T. Adair Dewey H. Newman, Jr. Robert N. Price Paul R. Caudill Jo Ann Dawson * * * * -1. * ·k * -1. * ` *David M. Daugherty on leave of absence since May l, 1959 This report compiled and prepared by Bruce Poundstone and W. J. Huffman Analytical data by Laboratory Staff Special statistical data, explained on pages 10 to 15 by W. G. Duncan 4 REGULATORY BULLETIN 164 This bulletin contains results of analyses of official samples of commercial fertilizer made during the period of January 1 through June 30, 1960. The average analysis of each plant food element and the coefficient of variation for each plant food are shown in Table l for each plant. The average percentage of guarantee and the coefficient of variation for all samples of a manufacturer are shown on pages 14 and 15. Separate tables are provided for the results of analysis of fertilizer, for boron and pesticides incorporated in fertilizer, and for the percent of potash equivalent to excess muriate where the guarantee for sulfate of potash was not met. EXPLANATION OF TABLES The information given should be useful to farmers, agricultural workers, and company representatives in determining how closely a given manufacturer and plant is meeting the chemical guarantee printed on the bag for all or specific fertilizers. This may be done by comparing the guarantee shown at the beginning of each listing of samples with the actual analysis in the colu ns at the right in terms of nitrogen, available phosphoric acid and potash. An additional means of comparing guarantees with the analyses of samples is in the percent of relative value found, shown in the extreme right—hand column. The following examples illustrate how this relative value is calculated: A 5-10-15 sulfate fertilizer is guaranteed to contain 5 units of nitrogen, 10 units of available phosphoric acid and 15 units of potash. Factors for computing the relative values of these plant foods are: 3 for nitrogen, 2 for available phosphoric acid and l for potash. Thus the combined guaranteed value of the product represented is calculated: 5.0 Units of Nitrogen x 3 = 15.0 10.0 Units of Available Phosphoric Acid x 2 = 20.0 15.0 Units of Potash x 1 = 15.0 Total computed guaranteed value 50.0 The sa e procedure is followed for "found va1ues." Assuming a sample of 5-10-15 was found to contain 5.1 units of nitrogen, 10.2 units of available phosphoric acid and 15.1 units of potash, the relative found value is computed: 5.1 Units of Nitrogen x 3 = 15.3 10.2 Units of Available Phosphoric Acid x 2 = 20.4 15.1 Units of Potash x 1 = 15.1 Total computed value 50.8 50.8 (computed found value of sample) divided by 50.0 (computed guaranteed value) A times 100 (to arrive at percentage) gives 101.6 as the percent of relative value found. In some samples a deficiency in one nutrient is accompanied by an over-run in another nutrient. This may be evidence of improper mixing or weighing by the manufacturer. Extreme variations of this kind cannot be attributed to separation of materials (segregation) after the product is bagged though this may be a minor factor. Excess of one nutrient cannot compensate for deficiency of another nutrient. The purchaser is entitled to receive the full guarantee of all nutrients as expressed by the manufacturer's guaranteed analysis. The results of analyses of all inspection samples are given in tables 1, 2 and 3. If an analysis shows a deficiency of more than the tolerance, the amount claimed for nitrogen, phosphoric acid or potash, or if the percent of the relative value is 97 or less, the result is indicated by an asterisk. ~ COM ERCIAL FERTILIZER IN KENTUCKY, SPRING SEASON 1960 S COMPANIES REPRESENTED BY SAMPLES REPORTED IN THIS BULLETIN Allied Chemical Corp., Nitrogen Div. Cooperative Fertilizer, Inc. P. O. Drawer 61 Southern States Bldg. · Hopewell, Virginia Richmond 19, Virginia ` American Agricultural Chemical Co. Darling and Company 100 Church Street 4201 S. Ashland Avenue New York, New York Chicago 9, Illinois American Cyanamid Company Davison Chemical Company ` P. O. Box 383 Div. W. R. Grace & Co. Princeton, New Jersey lOl N. Charles Street Baltimore 3, Maryland American Liquid Fertilizer Company 2nd St. and St. Clair J. H. Erbrich Products Company P. 0. Box 267 1120 East 32nd Street Marietta, Ohio Indianapolis, Indiana I Armour Agricultural Chemical Co. E'Town Anhydrous Ammonia Company P.O. Box l685 Box lb8 350 Hurt Building Elizabethtown, Kentucky - Atlanta, Georgia E'Town Fertilizer Company Armour Agricultural Chemical Co. Cecilia, Kentucky Nitrogen Division P. O. Box 128 Farmers Fertilizer Company V Crystal City, Missouri Smiths Grove, Kentucky Associated Cooperatives, Inc. Farmers Prescription Fertilizer P.O. Box 9ll Guthrie, Kentucky 750 W. 20th Avenue Sheffield, Alabama Farmers Supply & Produce Co. P. O. Box 433 Bartlett & O'Bryan Fertilizer Co. Monticello, Kentucky 108 River Road _ Owsnsboro, Kentucky Federal Chemical Company 6h6 Starks Building _ Bluegrass Plant Foods Louisville, Kentucky P.O. Box 310 ~ Cynthlana, Kentucky Glasgow Fertilizer Company Box 295 Bunton Seed Company Glasgow, Kentucky 300-306 East Jefferson St. 7 Louisville, Kentucky Grace Chemical Company P. 0. Box A9l5 Burley Belt Plant Food Works Memphis 7, Tennessee Route #[0 Lexington, Kentuzky John Deere Chemical Co. P.O. Box l&17 Central Farmers Fertilizer Co. Pryor, Oklahoma 205 W. Wacker Drive Chicago 6, Illinois Hutson Chemical Company Railroad Avenue Chilean Nitrate Sales Corp. Murray, Kentucky 120 Broadway New York 5, New York International Minerals & Chemical Corp. P. O. Box 67 Lockland Station Cincinnati 15, Ohio 6 REGULATORY BULLETIN 164 Continued from previous page Commercial Solvents Corp. Semo Liquid Fertilizer, Inc 260 Madison Avenue Box 301 New York 16, New York Charleston, Missouri Commonwealth Fertilizer Co., Inc. Southern States Clark Coop. Morgantown Road Winchester, Kentucky Russellville, Kentucky Spencer Chemical Company Kentucky Fertilizer Works, Inc. 610 N. Dwight Building Box 595 Kansas City, Kansas W1nchester,Kentucky Land-O-Nan Warehouse Stenson Farm Supply Sturgis, Kentucky Horse Cave, Kentucky Louisville Fertilizer Company Swift & Company Div. Armour Agricultural Chem.Co. Agricultural Chemical Div. Nashville, Tennessee National Stock Yards, Ill. Mid-South Chemical Corporation Tennessee Chemical Company 1222 Riverside Blvd. Div. Armour Agricultural Chem. Co. Memphis, Tennessee Nashville, Tennessee Missouri Plant Food Company, Inc. Tennessee Corporation Sikeston, Missouri Lockland Station Cincinnati 15, Ohio Monsanto Chemical Company Tr1—State Chemical Corp. 800 N. Lindbergh Blvd. P. O. Box 123 St. Louis 66, Missouri Henderson, Kentucky North American Fertilizer Company U. S. Steel Corporation l&l9 Preston & Bergman Streets 525 William Penn Place Room 3004 Louisville, Kentucky Pittsburgh 30, Pennsylvania Ohio Valley Fertilizer Valley Counties of Kentucky Coop. P. O. Box 799 Box 35l Maysville, Kentucky Murray, Kentucky Olin—Mathieson Chemical Corp. Virginia-Carolina Chemical Corp. P.O. Box 99l AOI East Main Street Little Rock, Arkansas Richmond, Virginia Price Chemical Company West Kentucky Liquid Fertilizer Corp. 2600 Milk rs Lane P. 0. Box 507 Louisville 16, Kentucky Hopkinsville, Kentucky Ruhm Phosphate and Chemical Co. P.O. Box 361 Columbia, Tennessee Schrock Fertilizer Service Congervllle, Illinois Scope Chemicals 15h N. Sparta St. Sparta, Michigan COM ERCIAL FERTILIZER IN KENTUCKY, SPRING SEASON 1960 7 EXPLANATION OF "STANDING OF MANUFACTURERS" A The standings of manufacturers, by plants, as determined by the results of analyses of official samples are given on pages 8 and 9. Purchasers of fertilizer can learn through a study of this how well any manufacturer, or plant, met his guarantee on the samples analyzed. It should be noted that the first three columns of figures refer to number of samples and that the last three columns refer to number of analyses of nitrogen, phosphoric acid, potash, sulfate of potash, boron, and pesticides. Attention is directed to the third column of figures which gives for each manufacturer the percentage of samples that are equal to guaranty in all respects, and to column 6, which gives the - percentage of analyses that are equal to guaranty or within tolerance. This tolerance is on a sliding scale varying with the guaranty as follows: Percent Guarantee in Nitrogen, Phosphoric Acid or Potash Tolerance u i 0- 9 0.2 10-19 0.3 20-25 0.4 26-34 0.5 35-39 0.6 40-49 0.7 50-59 0.8 g 60 or more 0.9 TONNAGE OF FERTILIZER SOLD The tonnage of fertilizer and fertilizer materials sold during the period covered by this bulletin was 461,786 tons. This is 6 percent less than the 491,920 tons sold during the same period of 1959. There was a decrease of 26,409 tons of mixed fertilizer and 3,725 tons of materials sold this spring. Although there was 6 percent less total fertilizer sold in the spring of 1960 than in the same period of 1959, the actual plant food used was only 3 percent less. `B REGULATORY BULLETIN 16A Standing of Manufacturers, Based on Samples Equal to Guaranty in A11 Respects and Analyses within Tolerance - Spring Season, 1960 I Analyses of N, PZO5, K20, sulfate Sam les of otash boron and esticldes COMPANY AND PLANT Total Equal to guaranty Total Equal to guaranty or Number in all res ects Number within To1erance** Number Percent* Number Percent* Allied Chem. Corp. Nit. Div. 5 A 80 5 5 100 American Agric. Chem. Co. A00 251 63 1,307 1,187 91 Cincinnati., Ohlo 155 90 58 51A A73 92 X Johnson Clty, Tennessee 1 1 -- A A ··- * Knoxville, Tennessee 1 0 -- 3 2 ·-- ’ London, Kentucky 179 12A 69 576 525 91 Nashville, Tennessee 38 21 55 132 115 87 Nat'1. Stock Yards, lll. 7 5 71 21 20 95 Seymour, Indiana 19 10 53 57 A8 8A American Cyanamid Company 3 3 -- 3 3 ·-- American Liquid Fert. Co. 1 1 -- A A —· _ Amour Agrlc. Chem. C0. 552 331 60 1,739 1,556 89 . Atlanta, Georgia A A -- 9 9 100 A Bartow, Florida 3 3 -~ 3 3 -- Cincinnati, Ohlo 225 153 68 718 665 93 E. St. Louis, Ill. 8 2 25 22 13 59 Jeffersonville, Indiana 117 71 61 375 337 90 Louisville Fert. Co. 13 A 31 37 31 8A Nashville, Tennessee 157 80 51 A98 A29 86 Sandusky , Ohlo 1 1 -- 3 3 -- Tennessee Chemical C0. 2A 13 SA 7A 66 89 Armour Agrlc. Chem. Co. Nit. Dlv. 6 5 83 6 6 100 Associated Cooperatives, Inc. 13 12 92 21 20 95 — Bartlett & O'Bryan Fert. C0. 67 30 A5 208 17A 8A Liquid 17 8 A7 51 A6 90 Dry 50 22 AA 157 128 82 Bluegrass Plant Food Works 239 115 A8 796 685 86 Cynthiana, Kentucky 100 50 50 357 313 88 Danville, Kentucky 139 65 A7 A39 372 85 Bunton Seed Company 3 2 -- 9 8 89 Burley Belt Plant Food Works 113 30 27 390 301 77 I Central Farmers Fert. Co. 3 2 -— 3 2 -- Chilean Nitrate Sales Corp. A A -- 6 6 100 Comercial Solvents Corp. 2 2 -- 2 2 -- Commonwealth Fertilizer Co. 98 A9 50 297 256 86 Liquid 17 5 29 51 AA 86 Dry 81 AA 5A 2A6 212 86 Cooperative Fertilizer Service A17 267 6A 1,278 1,179 92 Bristol, Virginia 12 10 83 35 33 9A Louisville, Kentucky 12A 100 81 390 379 97 Russellville, Kentucky 157 67 A3 A60 389 85 Wlnchester, Kentucky 12A 90 73 393 378 96 Darling and Company 28 16 57 81 71 88 Cairo, llllnols 22 12 55 6A 55 86 E. St. Louis, llllnols 6 A 67 17 16 9A Davlson Chemlcal Dlv. W.R. Grace 185 10A 56 577 500 87 Columbus, Ohio 1 1 ··- 3 3 ··-· Nashville, Tennessee 92 3A 37 290 233 80 New Albany, lndlana 92 69 75 28A 26A 93 J. H. Erbrich Products Co. 1 1 -- 3 3 -- E"1`own Anhydrous Armnonla Co. 3 3 -- 7 7 100 E"l`own Fertilizer Company 76 A3 57 235 212 90 Farmers Fertlllzer Company 6 A 67 20 18 90 Farmers Prescription Fett. Serv, [3 8 62 37 33 89 Federal Chemical Company 371 160 A3 1,170 936 80 Columbus, Ohio 3 1 -— 11 8 73 Danville, llllnols 2 0 ·· 6 3 50 * Percent is not indicated when number of samples is less than 5 ** See "Tolerance Scale" on page 7 · 3; :6 COMMERCIAL FERTILIZER IN KENTUCKY, SPRING SEASON 1960 9 Standing of Manufacturers, Based on Samples Equal to Guaranty in All Respects _ and Analyses within Tolerance - Spring Season, 1960 (Continued) ` Analyses of N, P205, KZO, sulfate Sam les of otash boron and esticldes CO1QANY AND PLANT Total Equal to guaranty Total Equal to guaranty or Number in all res ects Number within '1‘olerance** Number Percent* Number Percent* Federal Chemical Co. (Cont.) Humboldt, Tennessee 58 18 31 183 134 73 .. Louisville, Kentucky 178 101 57 581 508 87 Nashville, Tennessee 130 40 31 389 283 73 Glasgow Fertilizer Company 41 22 54 124 106 85 Grace Chemical Company 6 6 100 6 6 100 Hutson Chemical Company 51 20 39 163 133 82 International Min. & Chem. Corp. 242 119 49 768 646 84 Carlsbad, New Mexico 4 3 —- 8 7 88 Clnclnnati., Ohio 84 38 45 283 239 84 Clarksville, Tennessee 58 38 66 188 175 93 Greenville, Tennessee 13 8 62 37 32 86 Skokie, Illlnols 7 6 86 16 16 100 Somerset, Kentucky 76 26 34 236 177 75 A Kentucky Fertilizer Works 146 101 69 467 426 91 Land-0-Nan Warehouse 20 10 50 57 46 81 Llquid 10 7 70 30 28 93 Dry 10 3 30 27 18 67 Louisville Fertilizer Co. See: Amour Agric. Chem. C0. , Mid-South Chemical Company 7 7 100 7 7 100 l` Mississippi Chem. Corp. 3 3 -- 3 3 -- Missouri Plant Food Co. 5 3 60 14 l0 71 Monsanto Chemlcal Company A A ··- 4 4 -- North American Fertilizer C0. 137 96 70 446 415 93 Ohio Valley Fertilizer Co. 50 8 16 175 127 73 Olin Mathleson Chemical Corp. 2 0 -- 6 5 83 Price Chemical Company Bl 52 64 263 241 92 Rottger1ng' s Flowerland 1 l -- 3 3 -· Ruhm Phosphate Company 2 l -- 2 2 -- Schrock Fertilizer Service 1 0 -- 1 1 -- Scope Chemicals 1 l -- 3 3 -- O. M. Scott & Sons Co. 4 2 -- ll 9 82 Semo L1quid Fert., Inc. 1 1 -- 3 3 -- Southern States See: Coop. Fert. Ser. Spencer Chemical Company 9 9 100 9 9 100 Stenson Farm Supply 3 0 ·- 9 2 22 Swift 6 Company 16 8 50 53 44 83 Chicago, Illinois ll 5 45 35 28 B0 _ Greenville, Ohio 1 0 -- 3 3 --· Nat'1. Stock Yards, lll. 4 3 -- 15 13 87 Tennessee Chemical Co. See: Amour Agric. Chem. Co. Tennessee Corporation 94 50 53 287 258 90 Cincinnati, Ohio 33 18 55 101 93 92 · New Albany, Indiana 61 32 52 186 165 89 Trl-State Chemical Corp. 58 Z1 36 169 131 78 U.S. Steel Corporation l l -- 1 1 -- Valley Counties Coop. 20 ll 55 44 33 75 Virginia-Carolina Chem. Corp. 272 146 54 865 745 86 Cincinnati, Ohio 87 48 55 274 240 88 Hopkinsville, Kentucky 92 56 61 292 255 87 Memphis, Tennessee ll 5 45 33 24 73 Mt. Pleasant, Tennessee 61 21 34 191 154 81 Richmond, Virginia 21 16 76 75 72 96 West Kentucky Llquld Fertilizer 48 22 46 142 121 85 Bowling Green, Kentucky 13 6 46 38 32 B4 Hopkinsville, Kentucky 35 16 46 104 89 86 ° TOTAL 3935 2172 55 12,309 10,714 ‘ * Percent is not indicated when number of samples is less than S ** See "Tolerance Scale" on page 7 l0 REGULATORY BULLETIN 164 Y VARIATION IN FERTILIZER ANALYSES Variation is a basic trait in the analysis of fertilizer. The guarantee as printed on fertilizer bags cannot be accepted as an exact statement of the chemical contents. Rather, it tells what the manufacturer was aiming for and what the purchaser hopes to buy. This is true of all fertilizer. There is no departure from this principle. Evi- dence to the contrary is more likely a manifestation of variations of smaller magnitude. Many causes contribute to variability. Particle size and variability in chemical content of raw materials are an initial cause of variation. Methods of assembling, weighing, mixing, delivery into storage piles, and re-handling, including bagging, . present further opportunities for variation. To some extent these may cancel each other and thus minimize variation. They may progressively accumulate and thus magnify variation. The degree of variability in the final fertilizer product is in direct ratio to the variation introduced from these causes combined with the care exercised. Precision comes only through the use of properly classified ingredients, employment of methods that are reasonably exact and carefulness at all stages of manufacture. What has been said of manipulation in manufacture is likewise true of taking samples, their handling and analysis in the laboratory. This, too, may contribute to variation. Differences from this source, like those brought about in the manufacturing process, may tend to cancel each other or can accumulate. As in manufacturing, care and precision in the manipulation of samples will reduce the degree of variability. The variation caused in laboratory handling is normally much less than that in manufacture. For the purpose of this report, variations attributable to sampling and the laboratory may be disregarded. They are usually slight. Also all samples were taken by the same inspectors and handled in the laboratory in the same way. If there is "laboratory bias" it will be to change all results in the same direction to the same degree. WHY A CONCERN FOR VARIABILITY? The manufacturer and the farmer alike are interested in this question of varia- bility. Producers of fertilizer as well as purchasers want a product fully meeting guarantee. Manufacturers know that a certain amount of variability is unavoidable. This is a factor in suggesting "over-formulation" in the industry. The matter of how much over-formulation is necessary seems never to have been settled as it varies widely from plant to plant. Over—formulation becomes a contributing factor in product varia- tion, especially between companies. The aim or objective of manufacturing is to have . full guarantee as shown on every bag. If there is variability, it should be confined to values above the guarantee. From the user's viewpoint, if fertilizer is variable, some purchasers will get less than they pay for and others will get more. Also, with variability in composition, different areas in the field will be treated differently corresponding to the degree of variability. The user, therefore, is interested in variability to the extent that he gets what he pays for, and the fertilizer is sufficiently uniform to give the best possible agronomic return. The fertilizer official is likewise interested in this. His task is to see that each bag of fertilizer or the average of any two bags or whatever unit is selected is reasonably similar to other such units of quantity sold by a given manufacturer. Ferti- lizer laws infer that the average of the whole lot purchased should be at least equal to the guarantee. Although there are tolerances permitting some sauples to fall slight- ly under guarantee, these tolerances are not large and it is expected will seldom be applied. — (Continued) COM ERCIAL FERTILIZER IN KENTUCKY, SPRING SEASON 1960 ll REPORTING TH ANALYSES OF FERTILIZER _ In the past, regulatory reports of this Station have published results of thousands of chemical analyses of fertilizer samples. Some system of characterization is desirable · if these are to be meaningful. Several methods have been used to bring meaning to these data. Marking deficient samples with an asterisk is one of these. Supplementary tables have been presented showing the standing of manufacturers based on the criteria of the percentage of samples equal to guarantee in all respects and the proportion of analyses above tolerance. Two additional ways of diagnosing such data are proposed in this report. AVERAGE ANALYSIS, A MEASURE The statement has been made that the average of a given lot of fertilizer should at least equal the guarantee. If this is correct, an average of the analyses of several samples of such a lot will show whether or not this is true. The printed guarantee on each bag is viewed as the "aim" of the manufacturer. The average analysis of actual samples of the fertilizer becomes the means of statistically _ measuring the manufacturer's "true aim." The average analysis has been calculated for all of the analyses of mixed fertilizers reported in this bulletin when as many as two s mples are shown. These averages, given in Table l, follow the words "average analysis." { MEASURING VARIABILITY "Average analysis" as an expression of the "true aim" of a manufacturer, says nothing in the dimension of variability. Some measure is needed to express the range in analyses on either side of the average. To further use the analogy from marksmanship if "average" measures aim at the target and tells the center of this aim, another measure is needed to express the "scatter" of the various shots. Are they close to the center of "true aim" or are they "wide" of the mark? The coefficient of variation is proposed as a means for reducing this to a statistic that is useful. The method for doing this will be found in textbooks on statistics and when applied to a guarantee of SZ nitrogen is calculated as follows: Sample Number Nitrogen Guarantee Found Sguared A 5.0 5.6 31.36 y B 5.0 5.5 30.25 C 5.0 5.4 29.16 , D 5.0 5.7 32.A9 J E 5.0 5.5 30.25 · F 5.0 5.8 33.6h ‘ G 5.0 5.0 25.00 H 5.0 6.0 36.00 I 5.0 5.5 30.25 J 5.0 5.3 28.09 55.3 306.49 10 Samples, average = 2%;; = 5_53 0 (Continued) 12 REGULATORY BULLETIN 16h 2 s¤.·mdarddev1a¤1¤n= 306.49 - L = \/QQ = 0.275 l0 9 10 — l Coefficient of variation = 0-275 X 100 : Q_Q7 = 5_gZ 5.53 If in this example there had been less variation or "scatter," the resulting per- centage would have been smaller. If there had been more variation, it would have been ' larger. The coefficient varies directly with the range in values of analyses. · "WILD" SAMPLES b No matter how much care is exerted in a fertilizer plant, an occasional "wild" sample may appear. Such samples are caused by unusual circumstances such as putting the wrong fertilizer in bags labeled for another grade or large errors in mixing or manipulation in the factory that cannot be said to represent usual procedure. Com- putations that included such sa ples would only throw the coefficient of variation as well as the average analysis completely out of line. They are judged to be so abnormal they have not been included in these statistical determinations. There were only 57 such samples in the mixed fertilizer sa ples reported. Such samples are indicated in the table as "See note 8." As a basis for excluding these samples, the following rules were followed: 1. Throw out any samples more than 110% or less than 901 in relative value except: H- The sa ple is within j 10% of the average sample value. b. The variation of all the sa ple values is such that the samples more than j 10% appear to fit a normal distribution pattern. 2. Throw out all of a small group of less than (5) samples if variability is so great that no clear pattern is apparent. 3. Throw out individual samples whose ratio of ingredients differs strongly from the balance of samples of the grade. These may include samples: a. Whose ratio strongly suggests an entirely different grade of fertilizer. \ b. Two or more of whose ingredients are highest or lowest by 101 or more of the extreme value of the remaining normal samples. NOTE ON METHODS OF COMTUTATION USED It is apparent that the computation of coefficients of variation and even the simple averages for such a large number of samples requires a great many mathematical operations. The cost would make the operation impossible by ordinary methods, but the use of the digital computer leased by the University of Kentucky enables all of the g computations to be performed at a rate of approximately 5,000 samples an hour. (Continued) COM ERCIAL FERTILIZER IN KENTUCKY, SPRING SEASON 1960 13 The machine program for this work was developed especially for the purpose and is available for use on the computer at the University of Kentucky. It will be duplicated ` for use on other IBM 650 computers at no charge. INFORMATION GIVEN IN TABLES The coefficients of variation for each grade from each plant are indicated in table l. These are calculated for mixed fertilizer only and are shown when two or a more samples are reported. The coefficients of variation become more significant as the nu ber of samples increases. Coefficients of variation for all grades have been calculated for N, PZOS and K20 for each plant. Where more than one plant is operated by a given company, average coefficients of variation for each of the three components are given on pages lh and 15. Averages for plants or companies are given where as many as 10 samples were secured and then only if more than 2 samples were recorded for a given fertilizer grade. In one instance, a company had l0 samples but each was a sample of a different grade. An average c. v. could not be computed. The average percentage of guarantee for all samples for each element of plant food was calculated by plants. This likewise is calculated by companies in case more than one plant is shown. 14 REGULATORY BULLETIN 164 Average Percentage of Guarantee and Coefficients of Variation for all Samples by Fertilizer Manufacturers, Kentucky, Spring Season, 1960* Average Percentage of Coefficients of CGQANY AND PLANT Guarantee for all Samples Variation I "2°5 "¤° K *2**5 *20 (Percent) (Percent) (Percent) (Percent) (Percent) (Percent) X American Agric. Chemical Co. 99.9 102.5 101}, 3.3 2.4 3.3 Cincinnati, Ohio 99.2 104.0 102.2 3.7 2.8 3.1 London, Kentucky 100.3 101.4 102.0 2.9 2.7 3.4 Nashville, Tennessee 99.6 103.1 98.9 2.6 2.0 4.4 Seymour, Indiana 101.7 100.4 101.6 3.2 2.0 2.9 /a4.{ /¢.z J /44 Y Amour Agric. Chemical Co. 99:8 9979 1·09·r1 3.5 3.2 4.5 Cincinnati, Ohio 101.2 101.5 102.0 3.7 2.4 3.6 Jeffersonville, Ind. 100.2 103.5 103.3 4.1 3.4 4.4 Louisville Fert. Co. 97.7 104.8 101.8 2.4 5.3 3.0 Nashville, Tennessee 100.0 101.7 100.8 3.8 3.7 6.5 Tennessee Chemical Co. 99.7 103.5 101.5 2.7 2.2 2.3 Bartlett 6. O'Bryan Fert. Co. Liquid 101.2 104.6 97.7 0.9 3.5 3.6 Dry 102.1 102.4 101.8 5.9 4.9 6.9 Bluegrass Plant Food works 101.6 102.5 101.1 4.3 3.4 4.2 Cynthiana, Kentucky 100.8 102.3 103.2 4.0 3.4 3.6 Danville, Kentucky 102.1 102.6 99.5 4.6 3.4 4.8 Burley Belt Plant Food Works 99.0 100.1 101.6 6.9 3.0 5.1 Commonwealth Fertilizer Co. Liquid 100.7 103.9 100.4 2.3 5.5 2.9 Dry 102.0 101.7 104.6 4.6 3.3 5.7 Cooperative Fert. Service 103.0 102.2 100.9 3.0 3.1 3.2 Bristol, Virginia 102.8 105.4 103.2 5.1 3.7 2.6 Louisville, Kentucky 103.7 103.1 102.2 2.4 2.8 3.1 Russellville, Kentucky 103.5 100.9 99.4 3.8 3.4 4.0 Winchester, Kentucky 101.7 102.6 101.2 2.2 2.9 2.4 Darling and Company (Cairo) 103.0 104.4 104.3 3.4 3.9 6.3 Davison Chem. Div. W.R. Grace 102.3 103.8 102.1 6.0 4.2 6.0 Nashville, Tennessee 100.9 101.4 100.0 5.1 3.6 6.9 New Albany, Indiana 103.6 106.4 104.3 6.9 4.8 5.2 E'Tow·n Fertilizer Company 109.4 106.0 99.4 4.5 4.3 5.5 Federal Chemical Company 100.8 100.8 101.9 5.8 4.1 5.4 Humboldt, Tennessee 102.3 97.9 99.4 5.1 4.7 6.1 Louisville, Kentucky 102.1 102.0 102.2 4.9 3.6 4.3 Nashville, Tennessee 98.3 100.4 102.5 8.1 4.5 6.6 Glasgow Fertilizer Company 104.0 102.7 103.4 4.5 3.2 4.7 Hutson Chemical Company 104.0 101.0 101.7 8.0 5.2 5.3 COMMERCIAL. FERTILIZER Di KENTUCKY, SPRING SEASON 1960 15 Average Percentage of Guarantee and Coefficients of Variation for all Samples by Fertilizer Manufacturers, Kentucky, Spring Season, 1960* (Continued) Average Percentage of Coefficients of · COMPANY AND PLANT Guarantee for all Samples Variation _1 1*205 ¤