ESTEMARfiQ THE PEGMW???‘ 0i: MESHISM $031.3 Thasis far the {Ea-gm 01‘ M. S. {WECi'iiSAf‘l STfi‘aTE UHWERSQW WILUAM HERBERT failLLER ' 195.7 1»- ‘1 k! \N - ' a a r t LIUK 1‘1 Ii 3" NL-V.‘1£)... .. Univcusziy ’1 ABSTRACT ESTDHATING THE PRODUCTIVITY OF MICHIGAN SOILS by'William Herbert Miller The productivity of different kinds of soil under defined management conditions is of interest for determining optimum input levels, expected net returns with given management systems, land evaluation, and for resource inventory and planning work. Obtaining data upon which to base productivity estimates has been a major problem. The data obtained for this study was obtained from two sources: (1) growers selected from those cooperating with the Michigan State University Telfarm.project, and (2) growers cooperating with the Ionia County 1966 Corn Profit Club. Both sources were fairly satisfactory, the second being the more satisfactory. The methods used for gathering management practice data were found to be potentially useful for ascertaining the extent to which various management practices are being applied by the better Michigan growers. Methods for evaluating the crOps and soils management programs used by the growers has been another problem. A scoring method based on crop requirements and soil conditions was used in this study. The method is designed so that, using codes and card formats similar to those presented in this thesis, 8 computer can be given raw data and from them can com- pute a management evaluation score. The management scoring system was found to give fairly consistent results when it was evaluated by com— paring yields on the 2.5a (well drained loam) management group of soils. ‘William Herbert.Miller The need for.more precise evaluation of good management for high yields on the various groups of soils is evident. Average yields for each soil management group were found to differ with comparable management. The trend of differences in general is the same as that found in other studies. However, some exceptions indicate the need for additional research. ESTIMATING THE PRODUCTIVITY OF MICHIGAN SOIIS By William Herbert Miller A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIBJCE Department of Soil Science 1967 ACKNOWLEDGEMENTS The author wishes to express his sincere appreciation to Dr. E. P. Whiteside for his guidance throughout this study. Advice from the faculty and staff members of the Departments of Soil Science, Crop Science, and Agricultural Economics is also much appreciated. A great debt is owed the (Michigan) Cooperative Extension Service without whose cooperation this study could not possibly have succeeded. Dr. W. A. Tinsley and Mr. L. H. Jepson were especially helpful in the collection of the data. Special thanks go to the growers who so willingly gave of their time to provide the information used in this study. ii TABLE OF CONTENTS Page INTROUJCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . l LITERATUREREVIEM............. ...... 3 METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Factors Considered . . . . . . . . . . . . . . . . . . . . . . 6 Collection of Data . . . . . . . . . . . . . . . . . . . . . . 7 Evaluation of Data . . . . . . . . . . . . . . . . . . . . . . 15 RESULTS AND DISCUSSION . . . . . . . . . . . . . . . . . . . . . . 30 SUMMARY AND CONCIUSIONS . . . . . . . . . . . . ..... . . . . . 67 LITERANRE CITE O O O O O O O 0 O O O O O O O O O O O O O O O O O 68 iii LIST OF TABLES Numerical codes of some management practice variables Variable names and corresponding IBM card column numbers . . . . . . . . . . . . . . . . . . . . . . Codes for soil management group and unit symbols . . Response of growers to correspondence program . . . . Summary of 1966 management practice data . . . . . . . . . Average corn yields for different soil management groups or soil management units, under two management levels . . . . . . . . . . . . . . . . Average yields for some management practices for two groups of observations . . . . . . . . . . . . . . . . iv Page 16 l7 19 33 36 53 58 LIST OF FIGURES Figure Page 1. August rainfall compared to adjusted yield for Ionia Co. . . 31 2. Yield compared to original management score on 2.5a soils . . 6l 3. Yield compared to revised management score on 2.5a soils . . 62 INTRODUCTION The primary functions of a soil survey are to define soil types, locate them on a map, describe the taxonomic and mapping units, and Observe their relationships to land use and management for various purposes. The information provided by a soil survey often needs to be interpreted by relating the taxonomic and mapping units to other information available about the properties of these units. The re- sponses of these units to various uses and management practices in various climatic, social, and technologic situations are important interpretations of soil survey information. This thesis presents some methods that may be used to acquire and present'basic information on the productivity of soils for various craps under defined systems of management. This productivity infor- mation, as well as related information, is needed to interpret soil survey information for various groups interested in agriculture. Sole illustrations of these methods and their application in southern Michigan are presented. Many of the physical and chemical properties of the soil that vary from place to place are plant growth factors. A soil type is an attempt to meaningfully group these factors. (As used herein, soil type includes soil types and phases of soil types.) If these groupings are in fact meaningful, and if plants do in fact reSpond differently from one group of properties to another, then plant growth should be different from one soil type to another. Yield per acre is the plant growth criterion of greatest interest to agriculturalists. Yield, however, is the composite result of: (1) soil factors, (2) weather factors, (3) management factors, 1 2 (1;) unknown and/or uncontrollable factors, and (S) interactions among these factors. In order to determine the effect that the soil factors have on.yield, the effect that the other, non-soil,factors have on yield must be accounted for as completely as possible. Soil productivity, as used here, is defined as the average capacity of the soil to produce a given crop or a given sequence of crOps under defined management conditions in a given environment. Therefore, average yields for any given soil and management combination are a measurement of the soil's productivity if the non-soil factors are adequately accounted for, or their variations are represented in the data on which the averages are based. LITERATURE REVIEW The capacity of the soil to produce crops, and.the associated production practices necessary to achieve this capacity are items of information that are useful to a great many groups. For example, the evaluation of agricultural land by bankers, farmers, tax asses- sors, and land buyers can'be based to a large extent on such infor- mation, according to Anderson gt_gl (1938) and Priest (1963). Far- mers, conservationists, public land agencies, other public agricul- tural agencies, and agricultural industries find productivity infor- mation.helpful in planning Operations. Soil taxonomists can use pro- ductivity information to eliminate errors in the classification of soils (Ableiter‘gt_gl, 1950; Blagidov, 1960). Obtaining productivity estimates can be done two different ways according to Visser (1950). One method is to differentiate as accurately as possible between soil profile types, then use yield history to assign productivity figures to each profile type. A second method is to use yield history and individual soil preper- ties to determine the properties influencing productivity. Then productivity figures are assigned to the different soil bodies on the basis of the degree to which these properties are present. Using yield history to determine the properties influencing productivity, then assigning productivity figures to soil bodies on the basis of the degree to which these properties are present is a method strongly advocated by Butler (196h). Butler takes this ap- proach for two reasons: 1) He rejects the hypotheses that the morphological properties of a soil necessarily correlate with the soil factors responsible for plant growth. 2) He hypothesizes that 3‘ I . I, V I . I a .a . r - a l . ‘3. (.x T , . . I a - ll! . O. v . o . .. . n a . i I. . . . O. I. . I A , I. . b 0.. ..v w . O . a I . o . v I u. v . V .3 , . . . k - I . I r I t 95 r .. L c i (I ~ ‘ I .s t i . n I . h differences in yields can be correlated with differences in only a few soil properties such as pH. Northkote (19614), on the other hand, states that accumulated evidence shows that there is a constant and consistent relation beWeen the physical and chemical properties and the morpholog of the principal profile form. He further says that plant growth factors may correlate with groups of soil properties. Blagidov (1960) says that it is incorrect to appraise a soil for separate properties, then to appraisethe soil as a whole by ensuring up the appraisal data. He cites the example that a table of humus effects cannot be elaborated unless other soil properties are also taken into account. Blagidov consequently advocates that soil pro- ductivity appraisal be based on a specific conbination of soil properties. The relative productivity of each profile type can be assessed two ways according to Avery (1962). The first is to obtain yield measurements on two or more soil types within the same field. The second is to collect yield data on soil types which occur on scat- tered sites or fields. Tripp (1961;) in a study concerning the effects of slope and erosion on corn yields in Ingham County, Michigan, compared the yields obtained on adjoining soil types in the same field. Odell (1950) compared corn yield differences between Tame and Swygert series and various phases thereof in North Central Illinois by har- vesting adjoining plots in the same field. ' Collecting yield data from scattered sites or fields has been a more prevalent method of obtaining such data. Odell (1958) sug- gested three methods for obtaining information from scattered sites: S l) by survey, 2) from farm records, and 3) from experimental plot data. Anderson g_t_.__a_1_ (1938), Met'tert (1961), and Priest (1963) used land use records from different parts of a single county to estimate the productivities of the soils being studied. Odell and Smith (1910), Odell (19M), and Rust and Odell (1957) used records fro. individual farms .to assess the productivities of some Illinois soils. Information from individual farms has been used by Mettert (1961), Gonzalez (1963), and Search (1961;) to estimate the produc- tivities of some Michigan soils. 'Ihis is essentially the method used in this study. METHODS Factors Considered Since crop and soil management factors have such a large effect on yield, as pointed out by Kellogg (1955), Schrader gt_gl (1957), Aahndahl (1960), and Avery (1962), a system for assessing these factors was devised. In devising this system several points were considered. First, the factors employed in the system had to be judged to have a significant effect on yield. Secondly, the factors had to be related to practices commonly employed. Third, the system had to rely on factors about which information could be obtained. Fourth, the information ob- tained had to have a degree of accuracy which was known or which could be assessed. Fifth, the infermation had to be quantitative or quanti- fiable. Sixth, the system had to have potential relation to future pro- ductivity and had to be adaptable to assessing the crop and soil manage- ment factors in the future (see Aahndahl, 1960). Seventh, the informa- tion had to be able to be stored for future analyses. Not all of the relationships and considerations mentioned above were known when this project was begun. Two methods were employed to determine the crop and soil.management practices to include in a system fer assessing crop and soil management. First, infonnation in COOpera- tive Extension Service bulletins and similar publications, as well as theses, journal articles, and papers was used. Secondly, agricultural specialists at Michigan State University were consulted. Since weather, as pointed out by Dale (1965) and Range (1966), is such an important factor in.determining yield, an attempt was made to evaluate it. Amount of rainfall was the weather component used. 6 Collection of Data Several groups of growers were considered as potential cooperators with this project. In view of Odell's (19h?) experience, farm.0perators who keep'business records in cooperation with the Hfichigan State Univer- sity Department of Agricultural Economics Telfarm project were considered to be among the most promising potential cooperators. Other groups of potential cooperators considered were farmers cooperating with various County Cooperative Extension projects, those c00perating with Soil Con- servation‘Districts, and those cooperating with projects sponsored by agricultural companies. From among these, two groups of potential cooperators were chosen. The first group chosen were certain farm Operators cOOperating with the Telfarm project and the second group were growers participating in the Ionia County 1966 Corn Profit Club. ‘ The particular individuals selected from the Telfarm.project were chosen on two bases: (1) their Telfarm.FORM 9 record sheets indicated a possible high degree of interest in crops and soils, and/or (2) they reported crop enterprise information as part of a special phase of the Telfarm.project. Individuals in nine counties were chosen on this basis. Lists of these individuals and samples of the form on which the crop and soil management practices were to be recorded were sent to the respective COOperative Extension agents in order that the agent's epinion.could be used to determine whom.ehould be contacted. Finally, on the basis of the agents' opinion, the decision on whom.to contact was made. Accordingly, forms for recording the information and letters of introduction were sent to these growers. The information requested was the 1965 season crop and soil management practices. 8 Three methods of contacting these growers were used. In the first, a letter and one sample form were sent. A return postcard‘which the grower could use to request more forms if he elected to cooperate was enclosed. This same postcard could be used to indicate his election not to cooperate. The second method used was similar save that the number of recording forms sent was equal to the number of fields the grower had in corn in 1965. In the third method, selected growers in Jackson and Eaton Counties were contacted personally at their homes by the author with the aid of the respective Cooperative Extension agents. The experience gained in the program used to request information on 1965 season practices was used to help design a more effective program for requesting 1966 season practices. ‘With the help of interested growers, a form.for recording 1966 season crop and soil management prac- tices was designed. The respective Cooperative Extension agents were then contacted again. The following letter explaining the proposed 1966 program» examp plea of the 1966 season practice recording form, lists of the growers who coOperated in reporting 1965 season practices, and those growers being considered for contact in 1966 were sent to them. The agents were again requested to give their Opinion on whom it would be beneficial to contact, and when the contacts would best be made. On the basis of their advice, most of the forms were sent out in mid-June, after the heavy spring work was done. Along with the forms were sent the fol- lowing letter, the following example of a form already filled out, and the following explanation of the various items on the form. The growers so contacted were given a deadline by which to return the forms. In most cases, this deadline was approximately three weeks later than the date 9 MICHIGAN STATE UNIVERSITY EAST LANSING DEPARTMENT OF AGRICULTURAL ECONOMICS Hr. John.Doe May 13, 1966 Extension Agricultural Agent 123 Courthouse Square Somewhere, Michigan Dear Mr. Doe: Telfarm and the Soil Science Department are continuing their joint crop and soil analysis project. As you know, the agent is the key to success in this project. Your past cooperation is greatly appreciated. Enclosed you will find materials relating to our '66 program. Cooperating farmers will receive: (1) a letter; (2) a postcard addressed to Telfarm for questions and comments; (3) a "REFERENCE FOR FILLING IN PRINT-OUTS"; (u) a sample filled-out sheet; (5) a number of sheets equal to the number of fields owned in '65, not to exceed 20. The letter will encourage the cooperator to fill out one sheet per field for fields that have been soil-mapped, and that are devoted to the following crops: corn, oats, wheat, alfalfa hay, field beans, soybeans, and sugar beets. Cooperators would be asked to send in planting infor- mation with May and June Telfarm Reports. We will then send back these forms to be filled in with harvest information. The cooperator will receive these sheets back at the end of the year all nicely printed out far his records. Enclosed is a list of cooperators to whom you suggested we send the 1965 FORM A Questionnaires as well as cooperators who kept crop enterprise reports in 1965. We plan to send these forms out to these cooperators unless you suggest we add or delete some names from the list. Please advise. Your questions and comments will be appreciated. Dre. Tinsley and Kyle have been discussing this program with the District Extension Farm Management Agents. Sincerely, Bill Miller Department of Soil Science BH:lk Enclosures 10 COOPERATIVE EXTENSION SERVICE MICHIGAN STATE UNIVERSITY ° EAST LANSING ° MICHIGAN 48823 Agricultural Economics AND U.S. DEPARTMENT OF AGRICULTURE COOPERATING Agriculture Hall Kr. James Snith J 11:16 13, 1966 3.3. 1 Crossroads , Mich. Dear Mr. Smith: This is a follow-up letter concerning the crop analysis project being under- taken by Telfarm and the Soil Science Department. The system for reporting information has been simplified. If you are interested in cooperating, we need your assistance now. Please fill in the enclosed printout forms, one per field. An explanation of terms, for reference purposes only, is also enclosed. Of special interest are corn, wheat, oats, sugar beets, alfalfa hay, soybeans, and field beans grown in fields where the soil has been mapped. At this time, we need to know general field condition and crop planting information. Send these forms to us with your Telfarm reports, or use the enclosed envelope. These will be returned to you to be completed at harvest time. At the end of the year, a summary of the project will be sent to you. Ybu will also have these forms for your own records. The success of this project is dependent upon your close cooperation. There- fbre we say a sincere "thank you" for making it possible. For further infermation, contact us or your Extension Agents. Sincerely, 0“ ewe d as 357/7144 (3W) fi/Mm Leonard R. kyle Lynn 8. Robertson Extension Specialist in Extension Specialist in Agricultural Economics Soil Science 1k Enclosures P. 8. Please return the postcard as soon as possible. J . .T, j 1., r' I 1 ‘ PUPTTa TlLT i WAIT '1 NET ”FM? *PEIDE *INTEETTLE. PL 9 HA {"1" *PRE-SEADi» S'i *INCHED RAIN **SAA JELDTDV **‘3€1<'t’1 11;],ul { E, *REMAREN 11 1 1‘, , . , i“ x 1 517 0 {J :I’ A i 1 .. 1'3: ’ .. L! " /' T N In T" v? 3» 11' 2'1! 1'3“ '5: 7‘; 3'? 'fi' !r P ,:FLANTING EASEDNDED 59=ERDADCASTI leLleulD ':NANGANESE izllNC H .._,-F~TJROT\T :UTHER 7f/ 5772 * . .‘ ***#."~***‘A*i*i******************i********************* .1\1111 ’27a4yé7zc7b,9975? 213'4 5 6 7 8 TC T.) 2 " 1‘" LJ S-FDFL/DZZDDF D LD“TD. W'T’ *TLANITN‘ 4A a DEADLINE LL-A*T 5*A 1 2 D E-UULTTVATE 1(:)3 4 3-OTHEA 1 2 3 4 9 EAAEDIDI ES, TNSEDTICIDES. DTHEE CHEMICALS 1 2 EIDD 525$??gflyb LBS/ASH ;; DA AIME LBS/ACH BA HR DIAS LBS/ACE SA BE AIDE LES/ACE SE SE SDOD FAIR PDOR EESULTS(;%S 2~ -F 3 P RESULTS 1- 2-F EESDLTS 1 RESULTS 1- 2 F 2-F:~ {3635’} :(NOJCN . .9 ‘U‘O‘D DEDTL TEETED DY (:EFEET CD. 2-DSD 5-CDUDTY 4-ND TEST AT LEAST ES DDDE FEET DEPLIED AS TEST EEDDEAEDDATTDNS (ngEs 2-ND DFEATILITEE PLEA AT SIDE TOP“: 1 2 S DODN PLAET DRESS DRESS ANAL Ozgtg—Dy (:3 E z LES/ACE /579(1EFD 2-PLA 3- SD 4LTD ANAL Li E z ' EDS/ADE l-PD 2-PLA 3-50: 4-TD { AI‘TAL 3‘32 “/6 LI @Z LIBS LACE Z75 :L-PD @PLA L's-SD: S'TD ' DEAL LI D E LES/ACE l-PD 2~PLA 3-80. 4-TD ANAL DCZTéVwé L1 E z LES/ACE /;25’ l-PD 2-PLACZLSD. A-TD l-STAET MUNTH 5%g‘ DAY ,52 YEAR Z'FINTSH MDNTH DAY YEAR ELLA afim CJECZCTSU? fl: *NAAVEST DATE *TICLD/ACA’ H115 FIELD 1- BU /ézg’ 2- -TON PAPLADT DTSTDEE THAT TEE YIELD TS DASFD 0N AS”?Z YIELD EDSED DD (§>TE1S FIELD ONLY -AVEHAGED OVER 2 FIELDS OR MORE FETEDD 1F tAbUNIT 1 leD ETEDS 2 BINS s CRIBS 4- SCALES 6- WAGON LOADS 8 OTHER 3-CWT' (ELDRYEE EATCEES (”COUNT EAEES 12 REFERENCE FOR FILLING IN PRINT%OUTS General 2. Fill in information at the right of the designation as on sample. Where there is a choice, circle the number or the choice if no number. If information doesn't apply, leave blank. 3. Be sure to fill in your name and farm number. k. Abbreviations USed: MEMT. - MANAGEMENT LBS - POUNDS LI - LIQUID PD - PLOW DUNN G - GOOD BU - BUSHELS lfl- MANGANggg PLA - PLANTING F - FAIR ROT. - ROTARY Z - ZINC SD -SIDE DRESS P - POOR ACR - ACRE B - BORON TD - TOP DRESS PL. - PLANTING BA - BANDED O - OTHER CWT—HUNDRED WEIGHT POP - POPULATION BR - BROADCAST .AT PLANT - AT PLANTING Specific 5. Fill in the crOp, the number of the field on your 1965 Form 9 farm map, the township and section number the field is in. The ENTERPRISE NO. and LOT NO. are to use if you keep CrOp Enterprise Reports. 6. *SOIL TYPES, SLOPE, ... Leave this Space blank. The Soil Science Dept. will fill this in if your Form* 9 farm map is accurate enough to locate the field accurately on—E soil map. If this field has 223 been soil-mapped, please indicate under *REMARKS. 7. *LIME Ignore the code numbers l- and 2- in front of TONS and YARDS. Fill in amount used at right of proper units. Name kind used if you circle h OTHER. 8.*DRAINAGE USe your judgement to describe drainage condition of field. 9. *LAST MANURE APPLICATION Refers to barnyard manure, not whether field was pastured. We need only information for l965 and7or l966. For— your own records you may fill in for earlier years. Estimate amount applied. lO. *PRIOR COVER CROP Refers to crops like rye, clover, etc. sown between rows or after harvest for 1965- 66‘winter cover or green manure and which'was plowed down Spring of '66. Name kind of crop used. Describe stand. 'Ll.*INTERILLED FORAGE, LATE OR POST-SEASON COVER CROP Refers to either of two situations. (I) Refers to crOps such as alfalfa seeded in wheat, oats, etc., to establish the stand. (2) Refers to crOps seeded in l966 between the rows or after harvest for winter cover or green manure over Winter of l966-67. - 2 _ 13 l2.*PRE-SEASON MOISTURE Refers to'Winter and early Spring moisture status of the soil before planting. Use your judgement. 13.*INCHES This is strictly extra. If you keep rainfall records, we would RAIN appreciate your including them on one of these sheets. lh.*PROJECTED YIELD, ATTAINED YIELD Leave these blank. 'We'll fill in. lS.*VARIETY 'Write in variety or varieties used on field. Circle whether seed certified or not. l6.*SEEDING RATE/ACRE OR POP GOAL Ignore the code numbers 1-, 2-, and 3- in front of LBS, BU, and POP. Fill in amount at right of prOper units. CONDITION OF FORAGE STAND refers to hay crops like alfalfa or clover. USe your judgement to rate stand. l7.*PLANTING DATE Fill in dates you started and finished planting field. If field was planted in one day, fill in the day after START. YEAR is only for crOps not planted in'66 (Fall '65 or old forage stands). l8.*TILLAGE Circle when field was plowed. If plowed twice, circle last time. NO. OF TRIPS AFTER PLOWING, BEFORE PLANTING. One trip is one pass over field with a tractor and tillage tool. For example, if you plow, then plant the next day, you'd circle "0." l9.*HERBICIDES, ETC. Any chemical treatments against weeds, insects, worms, or other pests should be entered here. Enter actual lbs. of chemical applied. Circle whether BAnded or BRoadcast. If field was Spot treated, write SP to right of ER. 20.*SOIL TESTED BY If a fertilizer company took the samples or tested, circle l-FERT CO. no matter where the company sent the soil for testing. Please write the name of the company. If you can, write year of test and the sample number that applies to this field. Circle whether or not you fertilized by test. 2l.*FERTILIZER If fertilizer was liquid, circle LI. If Manganese, Zinc, or Boron was included in analysis, circle appropriate letter or letters. If some other micronutrient was included in analysis, circle "0". Write its name in front of ANAL. Fill in amount of fertilizer and circle time of application. If you heavily fertilized a previous cover crop, denote by circling l-PD. 22.*HARVEST DATE Use same procedure as for PLANTING DATE. 23.*YIELD/ACRE THIS FIELD Ignore code numbers 1-, 2-, and 3- in front of EU, TON, and CWT. Fill in yield at ri ht of proper units. For hay, fill in each cutting (2-TON3.5,4%for example . Fill in percent moisture of crop' that yield was computed a Please indicate how measurements were taken (counting silo rings, dryer batches, scale weights, crib measurements, wagon loads, etc. 2h.*REMARKS. Use this Space to fill in any information you feel has an important bearing on condition of field such as recent tiling, clearing from woodland, burying stone piles, land levelling, burying old buildings, oil leaks from wells, and so on. Also fill in anything you think had a significant bearing on yields such as insect damage, wind damage, irrigation, and so on. on which the forms were sent. The soils in each field were ascertained in a nunber of different ways. In counties where soil survey reports were available, the soil types and the extent of each was determined where possible by using the Telfarn FORM 9 farm sketch and comparing it to the soil map. The acre- ages of soil types in each field were usually determined by using a dot grid counter. In counties where soil survey reports were not available, soil naps made as part of a Soil Conservation District "Soil and Water Conservation Plan" were used. Where feasible, an area calculator manufactured by the Martin-Kuykendall Company of Albuquerqe, New Mexico, was used to estimste acreages of the various soil types in a field. ibis machine is an electric device designed to rapidly count unit areas. Growers cooperating with the Ionia County 1966 Corn Profit Club were also provided with copies of the crop and soil management practice forms through the Ionia County agent, Lance Jepson, who was responsible for conducting the corn club. He and cOOperating Ionia County vocational agriculture teachers personally interviewed the participating growers during the sumr of 1966. During these interviews, nearly all of the practice data were recorded. The data sheets were then sent to Michigan State University to be coded and readied for keypunching onto standard eighty column IBM cards. At harvest time, yields on each field were determined by hand harvesting the corn from a single soil mapping unit as shown on the recent soil maps made of Ionia County by the National Cooperative Soil Survey. These yield figures were then sent to Michigan State University to be included in the analysis. 15 Evaluation of Data 1. Evaluation of crop and soil management: A method for evaluating crop and soil.management programs was designed so a computer could be used for this work if desired. To facilitate matters, all of the factors used in evaluating management programs were given numerical codes. Elements of block coding and group classification coding (Vincent, 1965) were used in assigning the code numbers. Table 1 shows the code numbers given some of the variables. Those crop varieties that were considered the best were given the lowest numbers in the category. The format of data representation on IBM cards is shown in Table 2. It is compatible with the Telfarm card format inasmuch as the first 15 columns represent the same variables. The format is based to some extent upon the data in Table S. The consequent format design enables it to handle nearly every field situation on the three data cards. If necessary, however, additional pesticide or fertilizer applications can be put on separate cards. The soil mapping units were given, where possible, code numbers based on the (Michigan) State Legend for Series to be Used in New Progressive Soil Surveys, August, l96h, as revised. Soi1.management group symbols were given codes as shown in Table 3. Each soil.mapping unit name, its code number, and soil management group symbol codes were punched on a standard eighty column IBM card according to the format in Table 3. These cards enabled certain errors in assigning code numbers and management group symbols to be eliminated. The cards could also be used to assign soil management groups to the respective soil series in a computerized program to evaluate crop and soil 16 .998 pefi you eons 533% one no.8 Hedgehog...“ e noes: 93.33% 330.3qu * noose seaweeds-So Esme." messaged .3 gaeaumno nsoqassuefl scam...” mono Hoboo sflouenaoeufi «To? owes" fined-d. .82 oeoo condensates 33398.3 mm 8393312 coaches-......” £83.13 Boa x Simona alxooqshlo 18¢ €64 Cezanne and: 3.7mm assessing <8 Mancunian grand \Hefieesolfi 38.7mm e55 naaawua 69:2 Eugen n33 53.1 «RH-owe: 1538.3 Speculum nose-w 8oz oeoo 5383.3 Radon new. a 3333.8 ofinonefa taoafiom 31m 53......“ new} 3231. 333» sweatw woman." humid .oz 38 needs no .32 38 «atom 36o «To; and“ a3 3233. hoot: no.6 «mmn 8% man en: «Sn 8% Sun 88 no.6 33p assoc ease.— L woman hem biz 38 pooch e333 gnu 7933.3» 05 eeeoooha noise coco no.3 wean-awe» seasoned awesomeness case No eeooo Henge-52 .H canoe L/ /‘ 17 Table 2. Variable names and corresponding IBM card column numbers 001. 00].. Variable Nos. variable Nos. IdentifyingIEnformation 1-18 First data card (contgl on all data cards Cardffiumber 1-2 Symbol for additional 58 State B-h units which do not County* 5-? appear as a continuation Farm 8-11 of first data card Owner 12-13 Year lh-lS Year lime applied 59.60 Field 16-18 Amount of lime applied 61-62 (001. 62 is tenths) Kind of lime 63 First data card (No. 7;) Portion of field tiled 6h Acres in field l9-21 Condition of tile 65 (001. 21 is tenths) ‘Wet spots present that 66 delay operations Soil mapping unit #1 22q30 wet spots present that 67 Series No. 22-2h hurt yields Surface texture 25 Slaps 26 Erosion 27 Second data card (No.72) [ores 28q30 (Col. 30 is tenths) Crop 19-22 Soil mapping unit #2 31-39 Tbns manure applied 23.2h Series No. 31’33 Time 25 Surface texture 3h Year 26-27 Slope 35 Erosion 36 Prior cr0p 28.31 Acres 37-39 (Col. 39 is tenths) Prior cover crop 32-33 Kind 32 Soil mapping unit #3 110-148 Condition of stand 33 Series No. hO-lfi Surface texture h3 Intertilled forage 3h-36 Slope hh and/or cover crap Erosion hS Time planted 3h Acres 116-148 Kind 35' (Col. h8 13 tenths) Condition of stand 36 Soil mapping unit #1: 119-57 Series No. h9-51 Surface texture 52 Slope 53 Erosion Sh Acres 55-57 (001.57 is tenths) Table 2. (Canto) 18 C010 C010 Va riable Nos . Variable Nos 0 Second data card (contQ Third data card (No. 731 Variety 37-h]. Place soil tested 19 Maturity class 37 Extent to which test 20 Yield class 38 recommendations followed Kind 39-h0 Certification Fertilizer application #1 21-33 % N 21-22 Seeding rate, etc. b2-5’1 % P205 23.21; Units h2 1 K20 25.26 Rate 143-115 Liquid fertilizer and/or 27.29 (Col. 115 is tenths) micronutrienta Row width 1464;? lbs. fertilizer per acre 30-32 Condition of forage stand 118 Tims applied 33 Actual percent or 149-51 papulation harvested Fertilizer application #2 3km; z N 3 -3 Planting date 52-57 g p 05 36-37 Month planted 52-53 g Kgo 38.39 Day planted Sis-55 Liquid fertilizer and/or tic-M Year planted 56 micronutrient? N00 01' days between 57 Lbs. fertilizer per acre 113-945 start and finish Tina applied 146 Tillage 58-59 Fertilizer application #3 147-69 Season plowed 58 z N h7Ji8 No. of trips between 59 % p205 19.50 plowing and planting a: K20 51-52 Liquid fertilizer and/or 53-55 Weeding 60-62 micronutrients N00 rotary 110911183 60 lbs. fertilizer per acre 56-58 No. cultivations 61 Time applied 59 No. other weedings 62 Pesticide application #1 63-68 Harvest Kind 63-61; Month harvested 60-61 Rate 65.66 Day harvested 62-63 (Col. 66 is tenths) Units 624 Placement 67 Yield 65-72 Results 68 First hay cutting 65-66 Second hay cutting 67-63 Pesticide application #2 69-711 Third hw cutting 69-70 Kind 69-70 Fourth hay cutting 71-72 Rate 71-72 % moisture 73 ~71: (Col. 72 is tenths) No. of fields yield 75 Placement 73 based on Results ' 7h Method of measuring yield 76-77 19 Table 3. Codes for soil management group and unit symbols Symbols IBM card Category Standard Coded column Nos. Meaning_ Special L- 9 hS-hé lowland or alluvial soil —a 2 53-5h extremely acid soil -b 3 53-Sh soil calcareous at or near surface -h h SB-Sh soil having a hardpan Textural Upper story —- -- h7.h8 -- Lower story -- -- h9.50 -- O 01 fine clay (over 60% clay) I 10 clay 1.5 15 silty clay loam - clay loam 2 20 clay loam - loam 2.5 25 ‘loam - silt loam 3 3O sandy loam h to loamy sand 5.0 50 sand 5.3 53 very drouthy sand 5.7 57 extremely drouthy sand G 60 gravelly or stony soils R 70 bedrock or extremely rocky soils M 80 muck or peat m 83 marl Natural drainage a 1 well drained b 2 imperfectly drained (some- what poorly drained) 0 3 poorly or very poorly drained c S underwater Slope A 1 0-2 % B 2 2-6 % C 3 6-12% D h 12-18% E 5 18-25% F 6 25-15% G 7 16% K Erosion 0 0 none 1 l slight 2 2 moderate 3 3 severe h h very severe 20 management, as well as for other programs where such a transfer of infomation would be useful. The management evaluation system was based on the crop characteris- tics and requirements, and on the soil characteristics of the crops and soils studied. The proportion of different kinds of soils in a farm field was taken into consideration. The evaluation system was designed so that the one system could handle any cr0p and soil combination under study. A scoring system was designed so that each field was given a numerical management score. Each management factor was scored separ- ately, the score being based on the crOp and soil combination. The man- agement score for the field was the sum total of the scores for each of the individual management factors. Thus, no interactions among the management factors were considered. General 1. The percent of the field occupied by each of the three natural drainage classes of soils was determined. These percents were designated as "total a," "total b," and "total c," respectively. 2. The percent of the field occupied by each soil management group and byeach soil management unit was determined. These percents were designated as ”total soil management groups" and "total soil management units ," and given corresponding names such as utotal 2.5 a," and “total 2.5a02.” 3. The percent of the field occupied by the —a (extremely acid) soils, by -c (extremely limy soils), and by -h (hardpan soils) was determined. These percents were labeled "total -8," "total -b," and "total -h,” respectively. 21 Evaluation of lime A perfect score 10 could be obtained if any one or more of the following conditions were met: 1. 2. S. 6. The crop was corn, wheat, or cats. The crop was soy beans, navy beans, or sugar beets, and lime had been applied within the last 10 years. The crop was alfalfa,and.lime had been applied within 2 years of the year that the field was planted. The crop was soybeans, navy beans, or sugar beets, and ("total c ,1 'total b" __ 60 or ('total b“) __50 or ("total c") _ to The crop was alfalfa,and (”total c” / "total b") _ 90 or ("total c") _ 80. The soil was tested within the last lC>years and at least the amounts of lime recommended were applied. Otherwise, the score was 0. Evaluation of drainage A perfect score 10 could be obtained if any one or more of the fol- lowing conditions were met: . 1. 'Total a“‘_ 90. 2. l'T'otal a" _.80 and "total c‘l_ 5. 3. The field was entirely tile drained. h. The crOp was corn, alfalfa, wheat, oats, or sugar beets, and the field was partially tiled if ("total 0" ; "total b") __ 15. S. The crop was soybeans or navy beans and "total c"‘_ 20. Otherwise, the score was 0. 22 Evaluation of manure For each ton of manure applied for the crOp, credits of 6 lbs. N, 3 lbs. P205, and 12 lbs. K20 were given. These amounts were added to the amounts of nutrients applied by the use of commercial fertilizer. Evaluation of variety A perfect score 10 could be obtained if any one or more of the following conditions were met: 1. The crop was sugar beets. 2. The crop was wheat, and Genesee, Avon, Dual, or Monon was planted. 3. The crop was oats, and Ausable, Clintland 60, Clintland 6h, Garry, Rodney, or Cbachman was planted. h. The crop was alfalfa, and Vernal or Dupuits was planted. S. The crop was navy beans, and Sanilac, Gratiot, Seaway, Michelite, Michelite 62, or Saginaw was planted. 6. The crop was soybeans, and Blackhawk, Chippewa, Chippewa 6h, Harasoy, Harasoy 63, Hawkeye, or Lindarin 63 was planted. If the crop was corn, the score was assigned as follows: Maturity’ Yield class class high medium low early 10 7 2 late 9 6 0 If data on maturity and yielding ability were not available for a particular variety, the variety was not scored. 23 Evaluation of seeding rate The most extensive soil management group in the field was used to assign one of three soil classes to the field as follows: Texture NW H0,1,1.5,1.5/R,2,2/R,2.5,3 ,3/1,3/2,3/R,h,h/1,h/2 ,b/R,Sl{S/2,G,R a - 2 2 1 1 1 1 1 2 1 1 2 2 2 2 3 3 3 3 3 b - l 1 l l' l l 1 l l l 2 2 2 2 3 3 3 3 3 c l l l l 1 l l l l l l 2 2 l l 2 3 3 3 3 ‘17VND means natural soil drainage. .2/ M includes all types of'muck. ‘3/ 5 includes 5.3 and 5.7. A perfect score 10 could be obtained if the planting rate fell within the ranges indicated below, or if the crop was alfalfa and the condition of the stand was good. All seeding rates are in terms of pounds of seed per acre, except for corn which is in terms of population goal or actual population if data on actual population were available. Soil class Crop l 2 3 Corn 16.2 2000 11:16560 11.1115 CO Wheat 100-12 0 90—110 80-100 Oats 70-80 65 -75 60-70 Soy beans 50-60 bS-SS hO-SO Navy beans 37-h5 30-b0 25-35 Sugar beets 1-2 1-2 1-2 Otherwise, the score was 0. 2h Evaluation of planting date A perfect score 10 could be obtained if the crop was planted within the ranges indicated below, or if the crop was alfalfa. Range Crap from to (brn May 1 May 31 Wheat Sept. 10 Sept. 25 Oats April 1 May 1 Soy beans May 20 June 10 Navy beans May 25 June 25 Sugar beets April 1 April 30 Otherwise, the score was 0. If a time of four days or less was used to plant the field, it was ignored and the date planting was started was used as planting date. If a time lapse of greater than four days was used to plant the field, the date midway between date planting was started and the date it was finished was used as the planting date. Evaluation of tillage A perfect score 10 could be obtained if the crop was alfalfa, wheat, or cats. If the crOp was corn, soy beans, navy beans, or sugar beets, a score was assigned, as shown below, on the basis of the number of tillage operations (T.O.) between plowing and planting. A pass over the field with a tractor and one or more tillage implements was considered a tillage operation. No. T.O. Score 10 10 S 2 r o rwmwo 25 Evaluation of weed control A perfect score 10 could be obtained if the crop was alfalfa, wheat, or cats. If the crop was corn, soy beans, navy beans, or sugar beets, the score was assigned according to the number of points given the weed con- trol program. Each weed control operation was given the number of points shown below. One herbicide application : 3 points One cultivation : 2 points One rotary hoeing = 1 point One "other" weed con- trol operation 1 point The number of points given the weed control program was the sum of the number of points given each Operation times the number of times the operation was performed. This sum was used to assign a weed control score as follows: Points Score 6 ,t 10 11-5 6 2-3 3 0-1 0 26 Evaluation of fertilizer In the discussion below, "nutrients" is the sum of nutrients supplied by application of both manure and commercial fertilizer (gf. Evaluation of manure). A perfect score 20 could be obtained if the soil was tested and at least the amounts of nutrients recommended as a result of the test were applied. If the soil was not tested, the amounts of nut- rients applied were compared to a standard ("5" in the table below), and scores assigned accordingly, as shown below. The standards for N, P205, and K20 were the average amounts of each nutrient applied by all of Athe observations having the same most extensive soil management group in the field as the observation in question, (or the same most extensivesoil class (cgp23iinthe field if there were three or fewer soil management group observations on which to base the standard), to which were applied at least the amounts of nutrients recommended as the result of a soil test. Similarly, if one or more minor elements were applied for a particular crop in a county group (3f. Table 5., footnote 1/) to half or more of the most extensive soil management group (or soil class, pf. above) in the field observations as the observation in question, to which were applied at least the amounts of nutrients recommended as the result of a soil test, then the use of the minor element(s) was used as a standard. If there were more than one such.minor elements, all suchrminor elements together were considered as a single standard. Scores were assigned as shown on the following page. 27 ’ Minor N P 0 K O 2 S 2 elements (8 Zs (S 18 (S :8 (S :8 Score X X X X 20 X X X X 16 X X X X 8 I X X x 8 X X X X 8 X X X X 6 X X X X 6 X X X X 6 x x x x l. x x x x h x x x x b X X X X 2 X X X X 2 X X X X 2 X X X X 0 X X X X 0 Evaluation of missing data Where management practice data necessary for computing the management score were missing, an attempt was made to obtain them by contacting the grower or Extension agent. If the data were not thus obtained, but they could be estimated with reasonable accuracy, the estimates were used. If the data could not be obtained or estimated with sufficient accuracy, the observation was not included when the average yields for different kinds of soil were computed if the management score for the observation due to other factors was 65-7h. Otherwise, the observation was included. 28 Evaluation of field management score The highest possible score that could be obtained was 90. If the field management score 275, the field was placed in the ”good" management category. Otherwise, the field was placed in the "fair” management category. ~ EValuation of field soil_pattern If there were two or'more soil.management groups in the field, a yield was assigned to each soil management group by solving for Y1, Y2, Y3... in the equations below. Yf'Af El°Al fE2°A2 / E3'A3 k: Y1 2 k'El; Y2 : k°E23 Y3 = k'E3 where Yf : yield for the field. Y1, Y2, Y3... are the yields assigned to each soil management group. El, E2, E3... are the estimated yields assigned to soil management groups by the Cooperative Extension Service, Michigan State University (l966) in Extension Bulletin E-SSO, "Fertilizer Recommendations for.Michigan Vegetables and Field crOps." Af is the acreage of the field, and A1, A2, A3... are the acreages occupied by each of the "total soil management groups.” 29 Standard units Yields were converted to the standard units shown below if they were not reported in standard units. Percent moisture was assumed to be standard if it was not reported, except for corn. If percent moisture was not reported for corn, it was treated as missing data (£5. Evaluation of missing data. Crop Unit % moisture Corn bushel 1§?§W Alfalfa ton ---- Wheat bushel 13.0 Oats bushel 13.0 Soy beans bushel 13.0 Navy beans bushel 13.0 Sugar beets ton ---- 2. Evaluation of weather: An attempt was made to evaluate weather by trying to correlate inches of rainfall during the growing season months with yield. The average corn yields for Ionia County from 1950 through l96h were obtained from Michigan Agricultural Statistics (1951-1965), published by the Michigan Department of Agriculture cooperating with the U.S. Department of Agriculture. RESULTS AND DISCUSSION The adOption of better technology by growers in Ionia County has caused the average county corn yield to increase with time. The influence that this adoption of technology has had on yields was evaluated by obtaining the linear regression of yield on time. The equation so obtained was: Yield : 30.5 ,t 1.23 (year - 1950) The average county yields were standardized by subtracting 1.23 X (year—1950) from the average county yield for a particular year. These standardized yields were then plotted against the average inches of rainfall of the six precipitation recording stations nearest or in Ionia County, 212. Grand Ledge, Greenville, Hastings, Ionia, Lowell, and St. Johns. These averages were computed from precipitation data published by the weather Bureau of the U. S. Department of Commerce in the publication Climatological Data (1950-19614). The first rainfall parameter used was that of total rainfall during May, June, July, and August; the second parameter was June plus July rainfall; the third parameter July plus August rainfall; the fourth parameter August rainfall. This last parameter, August rainfall, gave the best correlation with.yield (Figure 1.). Consequently, a fifth parameter, inches of August rainfall reported from the Ionia station only, was plotted against standardized yield. This fifth parameter, however, did not correlate as well with standardized yield as did the rainfall average of the six stations mentioned above. The 1966 standardized yield and August rainfall value is very near the midpoint in Figure 1. This indicates that 1966 was a near normal year for corn production in Ionia County. However, with the improved technology used, the actual average Ionia County corn yield was 30 31 Average inches of August rainfall for six weather stations, l9SO-l9éh inclusive . t t : 30 no 50 60 Average corn yield (bu. per acre) in Ionia 00., l9SO-l96b inclusive, adjusted for trend with time Figure 1. August rainfall compared to adjusted yield for Ionia Co. 32 61.5 bu. per acre (estimated from Michigan Crop Reporting Service data). The equation on page 30 predicts an average yield of 62.2 bu. per acre for 1966, again indicating that 1966 was a near normal year for corn in Ionia County. The methods used to collect 1965 season management practice data were not very effective. As shown in Table h, only 17% of those con- tacted by correspondence responded. The three major reasons for the .lack of SUCCeSS'With the program for obtaining 1965 season management practice data are: (l) the form.used to record the practices was long mageldy and consequently most of the growers to whom it was sent found it difficult to use, (2) the request for information was made at the wrong time of year, both because the growers were busy with preparation for the 1966 season and because the time lapse since the practices were applied was long enough so that some growers had difficulty in recalling the information, and (3) the author was inexperienced in interviewing crop growers and had difficulty in obtaining reliable information from the growers interviewed in Eaton and Jackson counties. Response to the program of 1966 data collection was much more rewarding. As Table b shows, nearly four times as many and over twice as great a percentage of growers responded to the 1966 data collection program as to the 1965 data collection program. The probable reasons for this success are: (l) the growers contacted were those most likely to cooperate, (2) the time of contact coincided with n.1ull in their farm vwork, (3) the form on which the management practices were recorded was fairly simple, understandable, and easy to fill out (3f. page 11 for an illustration), (h) the growers contacted in the 1965 data collection 33 Table h. Response of growers to correspondence program Season for which data were sought 1965 1966 No. con- No. res- % res- No. con- No. res-‘ % res- Cbunty tacted ponded ponse tacted ponded ponse Calhoun 6 l 17 9 2 22 Eaton -- -- ' -- S h Bol/ Gratiot 6 O O 6 O O Ionia 6 l 17 -.2/ -- -- Jackson .-~ -- -- h 3 751/ Lapeer 6 1 l7 9 3 33 Lenawee -- -- -- 13 8 62 Saginaw 16 h 25 18 6 33 Sanilac 7 2 29 5 2 b0 St. Clair 12 2 17 12 5 L2 St. Josephl/ l -- 11 h 36 Shiawassee -- -- —- 25 6 2b Tuscola 12 l 8 13 h 31 Total 71 12 17 130 h? 36 l/ Growers were contacted by personal interview for 1965 data. This prObably explains the high rate of response for'l966 data. “2/ Only 1966 Corn Profit Club growers were contacted. 2/ Growers were contacted by the Extension agent for 1965 data. Infor- mation on how many were contacted is not available. County is not included in totals for 1965. 3h prOgram who were not interested in c00perating with the project were not contacted in the 1966 data collection program, (5) many of the Cooperative Extension agents and growers were familiar with the data collection project because of their contact with the 1965 data collection program, (6) some of the growers in Lapeer, Lenawee, Sanilac, and St. Clair counties were contacted personally by telephone by the author and encouraged to fill out the data forms, and (7) in the case of the Ionia County 1966 Corn Profit Club, the growers were personally interviewed by experienced personnel in connection with an activity in progress. The highest rate of response obtained in the 1965 data collection program was from Sanilac County. Both of the growers who responded were contacted by the author by telephone and encouraged to fill out the data froms sent them. The second highest rate of response was from Saginaw Jounty. The fact that growers in Saginaw County generally have a high interest in crOp and soil management compared to other Michigan growers probably helps explain part of this comparatively high rate of response. The two highest rates of response obtained in the 1966 data collec- tion program were from Eaton and Jackson counties. The greatest single reason that the response was so high is the fact that these growers had been personally introduced to the project by the author cooperating with the respective COOperative Extension agents. The fact that the agents were also thus introduced to the project also favored the high rate of reaponse obtained. In both counties these agents were requested to enc0urage the growers to fill out the data forms. 35 Both of the agents did so. In Lenawee County 62% of the growers res- ponded. The two factors which are probably most reaponsible for this high rate are: (1) most of the growers were contacted by the author by telephone, and (2) the Extension agent was extremely cooperative and did a great deal to encourage.the growers to fill out the data forms. Sanilac and St. Clair counties also had above average rates of response. The personal contact by telephone was probably the reason that the res- ponse was so high. Personal contact is evidently the most successful method of introduc- ing growers to this kind of data collection project if the data in Table h are significant. An initial personal contact with a follow up by correspondence such as used in Eaton and Jackson Counties seems to elicit a very high rate of response. Encouragement given the growers by the Extension agent seems to also be a big factor in determining whether or not a correspondence program is successful. ' The kind of information obtained from the responding growers is an important criterion in determining how successful the data collection program was. Table 5 shows to some extent how successful the 1966 management practice recording form and accompanying "REFERENCE FOR FILL- ING IN PRINT-OUTS” (2;: pages 11-13) were as vehicles for obtaining crop and soil management information. Prior cover crop was reported for 18% of the fields planted to corn in Group 1 and 2 counties, yet an intertilled crop was reported for only l% of these same fields. An intertilled crop was reported for no field in Ionia County. There's a good possibility that these figures should be more nearly equal than indicated by Table 5. 36 .930 no.“ confides—Sm obs mm: meme huge—g \m So 3.358 N 96.5 30.5 empaodom \M .nad papa E8 8.3 358 aHeaH e5 28% 3% on mama..." magma erase as .980 .Sa \N , .3825. use ..HHwHo .pm wowdmcmm asmsHmmm mam mmapssoo m 96.5 .smmmow 5m. use .mmmmmzmanm .mmswcoq ..Hmmamq aH8833. 53mm agonfimo 0.3 33:58 H 35.5 \m r OH NH OH Seam me E 3 Hang \mfioflaa .. -- .. .. .. mm om OH eH o: a .. .. .. .. H m H ass eaHHafiSeH .. Ha Hm .. em a m m mm mm mH -- .. -- -- mH mH aH ass Sees nova .. OH OH .. MH MH m H NH .. Z 3 e mH mm mm mH R SQmXHvaaaaaa HH .. am .. 2 mm m mm om 3 mm 3 NH mm 2 8 N 8 23 0H Hm am a mm mm NH om cm H H: 2. NH 8 a: eHN mm SH aeHaE .02 a a mH a a ON a. MH mm a mm mm a Hm fl. as H am 33.02 m a emm ans HHae HHaa. HHHJ» $358.02 mpomn names enema. memo pee—S agenda \dXMEQO panacea." \NH mwzm \thwz how how 38 no.6 A léofipsoo 8.3560 no macaw 50p 50.8 were 8. chem: v.35 23 $3338 m 38.5 Son.“ 3% on H.“ 980mm on... .mmfipnsoo IH 96.5 88.... same op 20mm." 998 some amen: enema...“ emu: one 633% mm: 003093 23. £033 on m Hen no mmmgnooeom one roach. 3.3qu on» 630: omwionpo mmodcbv 3mm 00.3095 pcoEmmmsms 8“: Ho base-56 .m erae 37 mpmen ummsm om mH mm Na mswmp mm OH HN H; mm mm om om Manon hem 5w MH aH H: mm mm mm om mm pm 00H mm an n: m mH a .. 0H mH .. MH ll OH ..I O m as mH HN e EN mN u- an on me NN m mm m m NH m o I: m memo amass. aeHeeHa auto mono emphoema hpefium> seepo seamen omawswm poavmac ohoxzwm hommumm as «stamens mo homwamm «segmwcu guesswoo oe eaaHeaaHu menace oHnwmd< coed coco: mmmmcoo fifleflfiaz 738v :Hmnpmmusp evades: eovuoamn knommamo .m oHpae 38 HH Hm mm MH MH 5. OOH mH Hm «amen mm OOH Hm 3 om 3 ma om ma mcmep hem OOH OOH OOH mm mm mm om Na mm am mm He am am me mm mm em npuo pmesz mono m it HH mm mm Nm Hm h: pm He am me H» mm me aeHaeHa um 00 Has: ma mm ON mm 3 NH 090m 3.3 oanmm NH HHIOH mum O.m a.H.m.H a.H.o.H a.o-m.o musspm \ OOOHN ooooNumH oooeHumw oooaHv Hmow cOprHgmom meme wsHeemm weapons“ coaeeOHeHeaoO emHaHeaea eoz vaMHpAmO copycawu huommpmo a..a.aa .m eHeaa 39 hm OOH so mm 4m OOH Om S wN OOH am mo OOH OOH NH mm Hm m4 mm OOH OOH OOH >4 O O» Hm no OH mm mm Om Om OOH MH mp mH Om OH NH mm mp NO ON OOH.bm mm eN H mm mm OH 03 ma Umphomma :psz 30m 3.2 aria Neam em.mN e -- as see sea: as mm mm Hm mH om NH empaoqmn even qupomm m.m..o.m a.N..m.N a.N..o.N «Jumé nHonmsm mm mm ONHIOm and. 2-0m Omu. qudom names hywz mpmop hmmsm mammn how memo ewes: wMHmMH< copeogen hpomepmo choc echo 383 .m ass hO Hm mN 0H mm mm OH cu m mm mH n no NH O OH 04 mm 3 mo mH Nm mm mm 50 NH om a a 3 3 Hm 8 mm OH O muom 2H2. mHIOH 0:55 muH mesa m HH page 3 m; NN ON 5 mH HmuoN he: deH has aH..H at: muH be: hes 3.8 H23 aHdH .334 “TH H23 none: came msHpneHm rophoamn ...noHpHuaoo noom nHmm coco vampm emmeom mo QOHuHusnO mason Amman memes hbmz names Mom memo ewes... «MHwth :nQu weaponry hhommpmo mono A.p:oov .m mHnt bl mm Ho «N om mN Hm mm NH Nm cmpmprHso mN mm me No me mN mm mm ow 00 mm 00H om Nm om umppoamg oooMQHHP .02 -- -- -- -- -- -- -- -- m .. HH .. -- -- -- I o mH ..- .... I: In E. 1: 0H 0 0m H H w H a I. m: NH mm mH MH m H mm 0 mm H 0 HH 4 m 0 mm HN mm NH 4: N: m: on mm mm mm mm mm Om N No mH mm -- mm 0H 0 ON N mH m on ma mm mm H -- -- -- -- -- m -- m -- u- -- Hm mH 0H Hm o mcwpcmHQ “w .onm :33me 23.3 .oz 00H 00H Nm OOH om Na 00H mm mm om mm 00H Hm om mm umpuoamg mpwu mnHacmHm a -- m HmroN .poo 4H 3” Wm mIH 250 mm No om om-om .pamm NH E. N mHIOH .38 3mg 2me 283. 33 93:3 3H3: Eco vmohommh umwdm biz Mom homopmn. no.3 r H.9qoov .m mema 9tho mmOHOHpommcH on mummmm \M .vmusHocH ohm Ommm :oHamvcsom mo munHH m>Hh \m. .pmwnz op mmnHOHpme vaHana mum30hm comm QOHpmucsom 0:» map tho \w M OOH $ Hm mvmon hwmsm Nm mH 3 S mammn hbmz mm NO Om mm NH OH 0H t: mH a 3 9 mcwmn how hfi S m mm... 38 nu: H am mm mm mm H o... .... H u: mH I: “m: mH u- 40 OH HH [[Hm gammfia # g-aNF- fl n .. O\O\ \0 ON psog: auHaHHq anon achu Omvuoamh mmvHOHummm Hazpoucm <05 mHEwuhm :mewna Hovcmm aoamhmHO sauna conHE< chwH< ocopmpmm oustomo mom ocoxcusm nocHuan :Hpqu uonompnom Royce n.4.m ocHNappd nonHoHanmm uophomou b&38 H.9acov .m oHpma h3 mmz muouchncw OOOOHOxfli\m NO a. -- -- -- -- -- -- -- -- -- NH OH NH -- -- -- -- cogom mN OOH N mm. .. O O -- u- u- -- -u -- -- -- H -- H ocHN HO HO OH R N NH om .. m ON -- -- -- .. .. H N H mmmsmmcmz OH OH H NH .. -n u: an -- n- u- -n a- u: m O O O \m.pumm OHOOHH -- .. -- -- -- H O -- mO HN HO NO OO NO -- -- .. -- OmmmaO O3 OOH m -- -- so -- -- -- -- -- -- -- -- -- Om mm Om mm OmmmmgO OOHO OOH OOH OO OOH HO OO mO OO OOH OOH OOH O OH N NO NO ON NO OONHOOO OOOOOHN NO OH NH NH NH O O -- O OH N m -- m mm Nm Om Nm OzOO OmonN NONHHHOOOO Om NO OO NO OO om NO mm HO N AOm NO mm mO OOH Om OO OO Ompuogmp ...OmmmH OO O O OH NH O O -- OH O u- N O NH N ON O N O 02 cm ON Om Om mm OO NO 3 Om O OO Om HO Om OO Hm mm Om 2% OOHHOOO OONHHOO nhmw mpcsoaw OmO ICOEEOUPH me0H #4 HO OO HO OO HO OO NO OO ON NO HN OO NO NN OOH 0O mm NO Omppoaou Ommp HHOO mN mm OH HO O HO om ON HN HO OH O O OH O ON 2 NH 33 oz O O ON -- OH OH NH OH OH .. NN NH O ON ON NH NN OH Npcsoo NH O NH -- NN NN .. mm HH -- OH ON ON ON m ON ON ON .O mpmpm .OOHO Hm ON ON om NH OH mN mH HN OH ON NH -- NN N HN mH mN .oo OONHHHOOOO Umvmop don moanH mummn mcwmn mammn mpmo pwm£3 wuHmqu choc Omppommu .Hmwdm bmz how know 0&8 gone H.¢:OOO .m OHONN hh Since the request for information was made before some of the cover crops were sown in 1966, some of his difference may thus be accounted for. Confusion for the grower concerning this item may have been a more important reason these differences occur. Variety is an item.which should have been reported on every field. On the average, it was reported from 89% of the fields, with neither county group being consistently higher than the other, and no crop being far above average. Whether the variety used was certified or not was repor- ted for 87% or more of the fields for either county group, except in the case of the alfalfa fields, from which certification was reported more often than was variety. Fields for which certification was reported and for which'variety was not can perhaps be assumed to be the same variety reported for another field sown to the same crop by the same grower. Seeding rate was reported for 9h% or more of all the fields, except those sown to wheat or alfalfa, for which the tate was reported for only 86% and 73% of the fields, respectively. Row width was reported for 87% or'more of the fields, save fer soy bean fields in Group 2 counties, for which row width was reported for only 83% of the fields. The condition of the forage stand was reported on the average for only 65% of the alfalfa fields. The position of this item on the data form.may help account for the low'responsec Row width, however, should be even less noticeable by reason of its position, yet a high rate of response was obtained for this item. Table 5 shows that, in general, crop management information on alfalfa was reported in fewer cases than such information for any other crop. This may help explain the low rate of response concerning condition of the forage stand. 1:5 Planting date was reported for 89% or more of all the fields in either county group save for fields planted to corn and wheat in Group 2 counties which reported planting date for only 8C% of the fields. The number of tillage trips between plowing and planting was reported for fewer fields than some other management practices. The "REFERENCE FOR FILLING IN PRINT-OUTS," Item 2, states, "If the information doesn't apply, leave blank." Since some growers did not plow before planting wheat, and even more did not plow before seeding oats, they may naturally have assumed that this information did not apply. The number of tillage trips was reported for only 75% of the sugar beet fields. Some of these fields were plowed in the fall. Consequently, some of the growers may have experienced difficulty in recalling the information. ‘Wheat, oats, and sugar beets are the earliest planted crops in Michigan. Difficulty in recalling the information may explain why an item such as number of tillage trips was not reported on a high percentage of fields sown to these crops. It is more difficult to explain why the number of tillage trips was reported for so few (69%) of the soy bean fields. Growers seem to have little interest in soy beans compared to their interest in other crops. Table 5 shows that few soy bean fields received more than one fertilizer application. Also, only 59% of the fields planted to soy beans reported a pesticide application, whereas 8h% or more of the fields planted to Other row crops reported a pesticide application. This seeming lack of interest in soy bean culture may explain why the growers did not report this item for this crop. Information concerning whether the soil was tested or not was not reported as often as some of the other practices. Except for Ionia County, for no crop was such information reported for 90% or more of the fields. 1.6 Item 2 on the “REFERENCE FOR FILLING IN PRINT—OUTS" probably accounts for a great deal of this lack of response, since some growers may not have had their soil tested, and therefore left this item blank. Whether or not at least the amounts of fertilizer recommended by soil test results were applied was reported in comparatively few cases, excepting Ionia Cbunty. The highest response obtained for this item was for corn for which it was reported for only 59% of the fields. The way this item was worded on the management practice recording form may have contributed to this lack of response (93.- page II). Item 2 on the "REFERENCE FOR FILLING IN PRINT- OUTS" might also have discouraged the growers who applied less than the recommended amounts of fertilizer from reporting this item. Alfalfa and wheat are the crops about which the least information was obtained. These same crops have the longest time lapse between plant- ing time and the time information was requested. This may indicate that the information obtained from this correspondence program may have been recalled chiefly fromzuemory rather than from written records. The accuracy of the information.may be questioned on this account. The most effective method of obtaining data was that used by the Ionia County l966¢Corn Profit Club. This method, however, requires the cooperation of trained personnel. The extent to which this cooperation may be relied on at future times is not known. For corn, except for information regarding soil test, every other item in Table 5 was reported by the growers in the correspondence program for at least 9C% of the fields. Using this response as a criterion, the method of data collection by correspondence appears to be worthwhile to be considered for future data collection, at least for corn. The data in Table 5 can be used to some extent as survey data to h? help determine what practices are being applied by the growers of the crops studied. The growers who supplied this information are generally conceded to be some of the better growers in.Michigan. It may be possible to consider the data in Table 5 as representative of the practices applied by the better growers in.Michigan. Shown below is a comparison between the percentage of all fields reported from Group 1 and 2 counties devoted to each crop studied and the percent of harvested Michigan field crop land devoted to each such crop in 1965 according to Michigan Agricultural Statistics (1966). Z land devoted to each crop Table 5 Mich. Agr. Crop data Stat. data All corn h6 31 All hay 17 27 'Winter wheat 12 13 Cats 6 8 Soy beans 7 7 Dry beans 9 10 Sugar beets 5’ l The figures are comparable for wheat, oats, soy beans, and dry beans. There are considerable differences for corn, hay, and sugar beets. Since the growers were requested for information on alfalfa fields only, this may explain some of the variance between the figures. These growers are generally situated on better land, as evidenced by the relatively high proportion of land devoted to sugar'beets. This probably accounts for the relatively high proportion of land in corn. It may thus be assumed that the data in Table 5 are biased toward better growers situated on better land 0 he Table 5 shows that the highest percentage (52%) of fields limed are those devoted to alfalfa in Group 1 counties. This is the trend expected since Group 1 counties include a large prOportion of relatively acid soils. Comparatively few fields were reported as limed in Group 2 counties, except those devoted to wheat (27% limed). The soils in Group 2 counties are generally quite basic and do not need lime. Since wheat is an upland crop, it tends to be grown on the better drained (and consequently'mmrekcid) soils requiring lime. It thus seems that lime is being applied where most needed. Relatively little manure was applied in Group 2 counties compared to Group 1 counties, except for corn fields, for which it was applied to 18%. Many of the farms in Group 2 counties have no livestock from which to obtain manure. Since the growers seem to exhibit such a high degree of interest in corn culture, it would be expected they would apply what manure was available on corn land. The high percentage (61%) of navy bean fields for which a prior cover crOp was reported is difficult to explain. The data concerning prior cover crop mg be quite inaccurate as explained above. As expected, an intertilled crop was reported for the most part for wheat and oats. For both crops, the percentage of fields in Group 2 counties reporting an intertilled crop was twice as great as the percentage in Group 1 counties. It mmy'be surmised that one of the chief reasons wheat and oats are grown in Group 2 counties is to establish a sod crop such as alfalfa, while in Group 1 counties these crops are grown primarily for the sake of the harvest from the crOp itself. varieties other than those for which a perfect score was given in the 1:9 management evaluation program were reported for 15% or fewer of the fields, except for alfalfa (37%) and corn, for which.variety data was not sum- marized. This indicates that perhaps more varieties ought to be included in the perfect score category for alfalfa, since it would seem growers planting the better varieties of other crops would plant the better varieties of alfalfa. All of the alfalfa fields for which certification was reported were sown to certified seed. It can be seen that certified seed tended to be used in a greater percentage of cases in Group 2 counties than in Group 1 counties. Half soy bean fields, slightly less than half of the oat fields, and only 39% of the wheat fields were reported town to certified seed, whereas 81% of the navy bean fields were reported sown to certified seed. Cbrn, wheat, oats, and soy beans tended to be planted at rates higher than those indicated on page 23, whereas navy beans and sugar beets tended to be planted at rates comparable to those on page 23. Narrow row widths for corn (32 inches or less) are reported for h3% of the fields in Group 2 counties, for only 12% of the fields in the Group 1 counties, and Only 15% of the fields in Ionia County. Since growers in Group 2 counties have narrow row equipment for navy beans and sugar beets, and since narrow rows for corn are becoming more popular, this can be expected. The high cost of converting to narrow row equip- ment in Group 1 counties explains why comparatively few corn fields from this group were reported as having narrow rows. 8 In general, planting dates reported for corn, oats, soy beans, and navy beans were comparable to the ranges on page 2h. A large proportion, (about 30%), of the wheat fields were reported planted outside the range 50 shown on page 2h. For sugar beet fields, 31% were reported as planted outside the range shown on page 2h. A very late spring in l966 helps explain this. It is interesting to note that only h5% of the oat fields in Group 1 counties were reported planted before April 20, whereas 92% of the oat fields in Group 2 counties were reported planted before this date. In general, the growing season starts about ten days later in Group 2 counties than in Group 1 counties. This early planting of oats in Group 2 counties may reflect on the timeliness with which the growers in each group perfOrm their operations. Minimum tillage seems to be in general use Only for sugar beets and for corn. .Only 7—28% of the fields sown to other row crops reported less than two tillage trips between plowing and planting. Despite the heavy use of herbicides reported, over half of the fields devoted to row crops are still cultivated. The fact that.l7% of the fields in Group 1 and Group 2 counties reported insecticide applications is indicative of the concern growers have for corn culture. The fact that not less than 56% of any group of row crop fields were reported as having no pesticide applied shows that chemical pest control is much favored by this group of growers. ' In general, no soil test agency compared to another is overwhelmingly used by any group of growers. An exception is the use of county facilities by the Ionia County group. It is striking that such a large percentage of fields in the Ionia County group did not apply at least the amounts of fertilizer recommended, especially considering the fact that they were involved in a contest. Since profit was one of the criteria by which the contestants were judged, many may have tried to cut back on 51 fertilizer expense. Over 50% of the fields planted to corn were reported to have received an application of plowed down fertilizer, and an application of side dressed fertilizer, except for the Ionia group. The fact that only 38% of the fields in the Ionia group were reported to have received a side dressing tends to support the cost cutting hypothesis above. Liquid fertilizer is more popular in Group 2 counties than in Group 1 counties. This fact along with some of the observations mentioned above shows that the growers in Group 2 counties are applying more recent innovations than growers in Group 1 counties. This is the trend expected and may help to support a hypothesis that Table 5 data is representative for large groups of Michigan growers. The high percentage of navy bean and sugar beet fields reported to have received micronutrients shows that the growers responding from Group 2 counties tend to apply the most current recommended management prac- tices. The high percentage (33%) of soy bean fields in Group 2 counties for which manganese and zinc were reported helps discredit the hypothesis that growers generally lack concern where soy beans are concerned. Pessibly some of these fields were for foundation seed. That 5C% of the oat fields in Group 2 counties were reported to have received manganese can "‘ '3 be explained by the fact that five fields of foundation seed are included in this figure. One might expect that boron should be applied for more alfalfa fields in Group 1 counties than were reported since such a large proportion of acid soils are present in these counties. The influence that some of these management practices seem to have had on corn yield for fields involved in the Ionia County 1966 Corn Profit 52 {nub will be discussed later. The primary reason for the collection of management practice data was in order that the management factors on each kind of soil might be accounted for as much as possible so that the influence of the soil factors on yield might be assessed. Table 6 shows some average corn yields obtained on different kinds of soil under different management levels. The yield figures are based on observations from the Ionia County 1966 Corn Profit Club. The yields for the soil.management groups under good management are in general the yields predicted by the Cooperative Extension Service in Bulletin E—550. Except for the yields on the 3s and the ba groups, the yields obtained are within 10% of the yields given in Bulletin E-SSO. The yields vary according to the general pattern found in other studies. The average yields increase as the soil becomes less naturally well drained; they are highest for the 2.5 soils and decrease as the texture becomes coarser or finer. There are two notable exceptions to this pattern. Yields are higher on the 2.5a group (116 bu. per acre) than on the 2.5b group (lCh bu./acreg and they are higher on the he group (111 bu./acre) than on the 3a group (8h bu./acre). This latter discrepancy occurs because the yields are much higher than expected for the ha group and much lower than expected for the 3a group. The average yields achieved under fair'management vary in the same way with texture and natural drainage. Exceptions are the higher than expected yield on the Be soil aid the lower than expected yield on the 2.5b soil. Only three out of eight soil management groups, the 2.5a, the 3/2a, and the Be groups are within 10% of the yields predicted in Table 6 o 53 Average corn yields for different soil management groups or soil management units, under two management levels (Numbers in parentheses refer to number of observations on which average is based.) Soil Soil Soil mgt. mgt. mgt. group group group or Mgt. level or Mgt. level or Mgt. .1919]- Category unit Good Fair unit Good Fair unit Good Fair 501]. 1.5a met. 02 11h(1) 85(1) unit 1 B2 97(1 ..... yields-J Al 117(1) --.... 2.5a 2.5b 2.5c 02 111(1) ----- 82 115 3 107(2) Bl 116(12) 102(2) Bl 91(2) 101(k) A1 ------- ------ Al 127(3) 95(5) Al 121(k) 112(3) 2.5a / 3/2a C3 106(1) ...... Bl 110(3) ...... Al lhl(l) ...... 3/2a . 3/2b 132 ....... 109(2) A1 ------- 87(1) A1 113(1) ...... 33 3c 02 95(1) ...... 32 72(1) 75(1) B1 ....... 102(5) hAl ....... 97(1 Al 111(1) 131(1) a 32 111(1) ...... Bl ------- 93(1) Soil 1.5s 101:0) 85(1) mgt. 2.5a 116(16) loh(h) 2.5b 111(5) 98(9) 2.5c 120(h) 112(3) group 1 2.5a I 3/2a yields—/ 116(5) ------ 3/2a - ----- 102(3) 3/2b 113 (1) ...... 38 8h(2) 97(7) 3c 111(1) 131(1) ha 111(1) 93(1) Soil 1a 95 lb 110 1c 12o mgt. 2a 110 2b 120 2c 130 group 3/2a 105 3/2b 115 3/2c 120 yieldsa/ 3a 95 3b 105 3c 110 ha 15 hb 80 he 90 1 Data taken from Ionia County 1966 Corn Profit _/ Yields taken from Bulletin 13.550, Table 3 Club -..—-— ..-—.-....- "(uh—.1.— .1-o-a- Sh Bulletin E—SSO. The range in management scores for the observations under fair management was h0-7b, about twice as great as the range for the observations under good management. The fact that so many of the soil management groups under good management and so few of the groups under fair management are within 10% of the yields given in Bulletin E-SSO indicates that the definition of management presented in this thesis coincides fairly well with the definition used by the authors of Bulletin E-SSO. The similarities between the yields in Table 6 and those in Bulletin E-SSO furnish additional evidence that 1966 was a nonnal season for corn in Ionia county. In only two cases were yields Obtained under fair management greater than those obtained under good management, zig., the Be and 3c soils. The yields for the 3a.' soil.under fair management and the Be soil under good management are within 10% of the yields in.lulletin E—SSO. The yields for the 3a; soils under good management.were 95 and 72 bu./acre. The field yielding 72 bu./acre scored well on every'management practice, save variety. Information on the maturity and yielding ability of the variety was not available. Some possible explanations for this low yield might be: (1) a variety with poor yielding ability was used, (2) the microclimate of this site was poor for corn growth, (3) the site in question had a low level of productivity due to past treatment, or (b) an unfavorable lime-nutrient interaction occurred. Three tons of lime per acre were applied in 1966. The calcium may have made some of the phosphate unavailable, or a high pH may have created a minor element deficiency. 55 The unexpectedly high.yield obtained on the 3c soil with fair management may possibly be explained by assuming that some data are missing concerning the management program. Only 22 pounds per acre of nitrogen were reported applied. This is more than 100 pounds less than the average amount of nitrogen applied by all of the growers. One is led to suspect that a sidedressing of nitrogen was not reported. This field is partially tile drained, so it is doubtful that a high water table was in reach of the corn roots to make possible this higher than expected yield. The yields on the ha soils are much higher than expected. Since 1966 was a normal season for corn, these yields can perhaps be obtained with some regularity on these soils. The 111 bu./acre yield was obtained with.the help of 156 pounds of K20 per acre applied via the use of commercial fertilizer and manure. There is nothing particularly striking about the management program used to Obtain the 93 bu./acre yield. There‘wms another he yield which was excluded from.Table 6 because information on the maturity and yielding ability of the variety was not available. The yield Obtained was 113 bu./acre. The grower who obtained this yield is a seed dealer and can possibly be assumed to have used a variety with a high degree of’yielding ability. He applied 210 pounds of K20 per acre. The ha soils generally have physical characteristics favorable for plant growth. The infiltration of air and water into these soils is generally more rapid than it is into finer textured soils. With natural infertility overcome by the addition of fertilizer, these higher than expected yields do not seem unreasonable. The yields for the 2.5 toposequence of soils are the best documented 56 yields in Table 6. That the yields on the imperfectly drained soil should be lower than on the well drained soil is difficult to explain. This may indicate that the productivity of these soils has been over estimated in the past. When the yields from 2.5b observations are compared on the basis of whether lime was reported applied or not, the yields for the unlimed fields were much higher than for the limed fields, for'both the good and the fair management levels. These yields are shown below. Yield Lime Good *Fair reported Mgt. Mgt. Yes 102 86 No 118 , 103 The yield 118 bu./acre makes the 2.5b yields fit into the pattern expected for the tOposequence. It may be very possible that these 2.5b soils are overlimed. The 2.5b soils often occur in the same field with better drained soils for which lime may be needed. These imperfectly drained soils may be limed, not because they need it, but because they happen to be in thesame field.with soils requiring lhne. If this supposition is in fact the case, it shows how im ortant it is that the differences in soil within a field be considered when various management practices are applied. Table 6 also shows a striking similarity between the yields obtained under good management on the 2.5a I 3/2a soils and between the 2.5b soils and the 3/2b soils. The 2.5 soils and the 3/2 soils are apparently quite similar in their productivities. [A similar situation was noted by Search (l96h). That these two soils should be similar in productivity seems reasonable since both have a clay loam B horizon. The water holding capacities of each soil and nutrient supplies ought to be 57 somewhat similar. This leads one to question how important the upper h2 inches of these soils - ' is to productivity under present conditions of technology. I The deviations of the yields Obtained in 1966 from those expected point out the need for yield information on many more fields in a number of diffeeent years in order to evaluate the average yields for various management levels on most of these soils. It is interesting to note the economic implications of the differences in yield between good and fair levels of management. Corn sold at the elevator in January, 1967, brought an average price of $1.20 per bushel. Using the 2.5 toposequence as an example, the differences in gross income between good management and fair management are shown below. Gross income_per acre Good Fair Soil mgt. mgt. Difference 2.5a $139 8125* $lh 2 .5b 8133 $118 $15 2.5 c $51M; $1314 810 While these figures represent gross rather than net income, they do give some indication of the advantages the grower can realize by using good management. It has been estimated by Mr. Lance Jepson, Ionia County Extension Agricultural Agent, that 50% of the cost involved in growing corn is fixed. This makes it very probable that a large percentage of the above differences in gross income can be realized as net income. The average yields obtained with some of the different management practices are shown in Table 7. Neither row width or manure seems to have much effect on yield. That one tillage trip between plowing and planting is associated with such a high yield may show that one such trip is necessary to make the surface of the soil even enough so that a good stand can be obtained. Two such tripg,however, may excessively 58 Table 7. Average yields for some management practices for two groups of observations (All data are from the Ionia Cbunty 1966 Corn Profit Club. The number of obser- vations on which average is based appears in paren- theses.) Averagegyield ‘— 2.5a soils All obser- under good vations in Management practice management corn club Row width (inches) 30-36 115 (2) 111 (31) 38-110 117 (11) 107 (is) Nhnure applied 115 (5) ....... Manure not applied 119 (8) ....... No. tillage trips between plowing and planting 0 108 (b) ....... 1 ’ 127 (6) ....... 2' 110 (3) ....... Lime applied 111 (10) ....... Lime not applied 137 (3) ....... Planted on or before May 21 112 (7) 1C8 (39) Planted later than May 21 128 (S) 111 (35) Amount of fertilizer applied compared to amount recommended by soil test results Less than recommended ------- 95 (13) Same as recommended or more ------- 112 (h9) Kind of variety usedl/ High yielding, late maturing ....... 122 (13) High yielding, early maturing .- ...... 109 (9) Medium yielding, late maturing ------- 109 (8) Medium yielding, early maturing ....... 107 (13) 1/ Based only on observations for which maturity and yielding ability of the variety was available S9 compact . the soil. That lime seems to be correlated with lower yields is very difficult to explain. This is the third instance noticed in which lime application is associated with low yields. More research on the effects of lime and the frequency with which overliming occurs may be needed. That higher yields seem to be associated with a later planting date may be due to the fact that spring was very late in Ionia Cbunty in 1966. A higher rate of seed mortality probably occurred on the early planted fields compared to the later planted fields. The difference in yield achieved between those growers who applied at least as much fertilizer as recommended by soil test results and those growers who did not apply as much fertilizer as recommended is very striking. Part of the difference in yield may be accounted for if it is assumed that yields increased with the amount of fertilizer applied. Some of the growers who applied at least the recommended amounts of fertilizer undoubtedly applied a great deal more fertilizer than recommended. It might also be suspected that the growers who applied at least the reCOmmended amounts of fertilizer had higher management scores where other factors are concerned than did the other growers. However, when average total management scores for the management practices other than fertilizer application were compared for three different groups of growers, there were not wide differences among the groups. The average such score for those who did not apply at least the recommended amounts of fertilizer was 56.5, for those who did apply at least the recommended amounts, it was 59.2, and for those who did not have their soil tested, the score was 62.b. Table 7 also shows that the later maturing varieties tended to 60 yield higher than the earlier maturing varieties. The CbOperative Extension Service cautions against using late maturing varieties. It seems possible, however, that the late maturing varieties might be used to advantage if the corn is intended for silage. There is definitely a question concerning how adequately the influence of the management factors on yield is accounted for by the management evaluation system presented in this thesis. Especially, it must be questioned how adequately the system accounts for the influence of management factors on the coarser soils. Table 6 shows that over twice as many observations on the 3a and be soils were placed in the fair management category than were placed in the good management category, whereas 16 times as many observations were placed in the good management category as were placed in the fair'management category on soils with a texture 3/2 or finer. Moreover, yields obtained with fair’management on the 3a and 3c soils are higher than the yields Obtained under good management. Much of the research on which the management evaluation system is based was conducted on soils that had a texture of loam or finer. It may be that research results attained on these finer textured soils are not applicable, or at least not completely applicable, on coarser soils. This may point to a need for agronomic trial to be conducted on several different kinds of soils as suggested by Butler (l96b). Kellogg (1955) very clearly points out the need for research which is based on rec0gnized differences in soils. Figure 2 shows how adequately the management evaluation system accounts for variations in yield on 2.5a soils. That yield and manage- ment score vary together as much as they do is encouraging, since only two groups of factors, the management factors and the soil factors, 61 ® 160 -1)- <:) 'well drained soil 150 __ A moderately well drained soil CD 1110 -._ (D 13C) '1'- Yield