A Comparative Summary ofthe Standard Mehlich 3 Soil Test with

a Modified Mehlich 3 Dilution Ratio Procedure

W.H. Baker, C.G. Herron, S.D. Carroll,M.A. Henslee, D.C. Lafex, and E.E. Evans

A R K A N S A S A G R I C U L T U R A L E X P E R I M E N T S T A T I O N

Division of Agriculture University of Arkansas

January 2002 Special Report 205

Agricultural Experiment Station, University of Arkansas Division of Agriculture, Fayetteville. Milo J. Shult, Vice President forAgriculture and Director; Gregory J. Weidemann, interim dean, Dale Bumpers College of Agricultural, Food and Life Sciences and associate director, Arkansas Agricultural Experiment Station, Fayetteville. WebQX41. The University of Arkansas Divisionof Agriculture follows a nondiscriminatory policy in programs and employment.ISSN: 0571-0189 CODEN:AUARAN

Editing and cover design by Cam Romund

This publication is published on the web only at: http://www.uark.edu/depts/agripub/Publications/specialreports/

CONTENTS

ABSTRACT…………………………………………………………….…………………………………….1

INTRODUCTION……………………………………………………….…………..………………………1

MATERIALS AND METHODS……………………………………….………………………………....…..2

RESULTS AND DISCUSSION……………………………………….....………….………………………...3Explanation of the Graphs for Each Nutrient……………………….....………….……..................……....3Accuracy and Precision…………………………………………...………….…………………………....…3Correlation Between the Dilution Ratio Procedures…………….………….……………………………......3Average Differences Between the Dilution Ratio Procedures.…..…………..…………………………….…4Extractable Nutrient Levels and Soil pH Relationships………………………………………………..…….4

CONCLUSIONS………………………………………………………..……………………………………5

LITERATURE CITED…………………………………………….….…..………….………………………5

APPENDIX…………………………………………………………..………………………………………5APPENDIX A:Table 2...................................1-6Figures 1&2...........................7Figures 3&4...........................8Figures 5&6...........................9Figures 7&8.........................10Figures 9&10.......................11Figure 11.............................12Figures 12&13.....................13Figures 14&15.....................14Figures 16&17.....................15Figures 18&19.....................16Figures 20&21.....................17Figure 22.............................18Figures 23&24.....................19Figures 25&26.....................20Figures 27&28.....................21

1

A Comparative Summary ofthe Standard Mehlich 3 Soil Test

with a Modified Mehlich 3 Dilution Ratio Procedure

W.H. Baker, C.G. Herron,1 S.D. Carroll,M.A. Henslee, D.C. Lafex, and E.E. Evans

ABSTRACT

The Arkansas soil-testing program currently uses the Mehlich soil extraction procedure with amodified soil-to-extraction-solution dilution ratio of 1:7 instead of the standard 1:10 dilution. Thisstudy was performed in order to facilitate the decision process for making a conversion from the1:7 ratio method to the 1:10 ratio method. Four hundred seventy-one soils used in this evaluationwere selected to represent the major agricultural production areas in the Arkansas Delta. Each soilsample was extracted with Mehlich 3 solution at a dilution ratio of 1:7 and 1:10. The extractionsolutions were then analyzed for the major soil nutrients included on routine soil test reports.Analytical results from each extraction dilution were compared for each soil nutrient. Differenceswere noted and assessed for any significance that might affect the current fertilizer recommenda-tion break points and equations. Phosphorus was the only soil nutrient that indicated a need forfertilizer break-point adjustments if the extraction method is converted from 1:7 to the standard1:10 dilution ratio. Phosphorus levels were indicated to be significantly elevated with an averagedifference of +32 lb/A more P in the 1:10 extraction solution than in the 1:7 extraction solution.

INTRODUCTION

Analytical procedures used for routine soil test-ing attempt to estimate the amount of soil nutrientsavailable to the plant during its growing season.While soil fertility is an important component ofcrop production, most of the production expensesassociated with crop nutrition are low when con-trasted with the total cost of production. Therefore,the costs for a specific soil test method must be rel-atively low for an analysis to be of any practical use.The best way to achieve this is to capture as manyanalyses as possible using a minimum of proce-dures. The Mehlich 3 extractant (M3) was devel-oped as an attempt to accommodate as manyimportant plant nutrients as possible in a singleextraction (Mehlich, 1984). Many laboratories havepurchased simultaneous inductively coupled spec-trophotometers (ICP), and have incorporated M3into their soil testing program to take advantage ofthis more economical single-extraction procedure

(Wolf and Baker, 1985). This was certainly one rea-son for the use of the M3 extractant considered bythe University of Arkansas Soil Test Laboratory.

The M3 extractant was first considered for useby the Arkansas Soil Test Laboratory in 1985. TheUniversity of Arkansas Soil Test Laboratory was oneof the first soil testing facilities in the nation toincorporate a simultaneous ICP into their soil test-ing program. With this shift in new instrumenta-tion came the need for a new multi-element extrac-tant to take advantage of the ICP capabilities.However, it was noted that the standard method forM3 was using a 1:10 soil-to-extraction-solutiondilution ratio that did not match up to the existingBray P1 analysis for P (Richard Maples, personalcommunication, 1990; Donahue, 1983). A series ofsoil analyses was performed at different dilutionratios by the University of Arkansas Soil TestLaboratory using the M3 (unpublished data)method. It was found that a 1:7 dilution ratioagreed closely with the previous critical levels for

1Soil Testing and Research Laboratory, Department of Crop, Soil and Environmental Sciences, University of Arkansas, Marianna, AR 72360.Corresponding author (email: cherro@uark.edu)

nutrients used for making fertilizer recommenda-tions. The decision was made to modify the M3method from the standard 1:10 dilution ratio to a1:7 dilution ratio so that soil test P values remainedvirtually unchanged between methods. This keptthe transition to the new M3 extractant and the newICP instrumentation as straightforward as possiblefor growers and consultants. Over the last 15 yearsthis modified method has served the needs ofArkansas farmers well.

With the acceptance of precision agriculturetechnologies, soil samples are being used to producesite specific maps of the fertility status of produc-tion fields. In addition, the information obtainedfrom soil samples is being stored in long-term data-bases. The new emphasis on geo-encoded soils datahas shifted the action from fertilizer recommenda-tions to the analytical output. When the decisionwas based primarily on the fertilizer recommenda-tion, the analytical value could afford to be differentdue to different methods or modifications to amethod. Methods and their results could vary, butthe research-based correlation and calibration data-base would produce similar recommendationsacross methods.

This work was put forward as a basis for devel-oping new soil-test action level points based onanalyses using the standard M3 1:10 dilution ratio.The specific reasons for this research are:

1. Part of the Arkansas Soil Testing Lab qualitycontrol and assurance “good lab” practicesinvolves participation in the AmericanSociety of Agronomy North AmericanProficiency program (Miller and Wolf, 1998).This program only accommodates theunmodified 1:10 M3 extraction method.Proficiency testing causes the University ofArkansas Soil Test Lab to abruptly change theroutine process from a 1:7 to a 1:10 dilution.Use of an altered M3 method does not meetthe true intent of proficiency-testing qualitycontrol performance evaluations.

2. When clients switch or compare analyticalresults between the University of ArkansasSoil Test Lab and other nearby private or pub-lic labs, they are, in effect, comparing datafrom two different systems and causing theirinterpretation of the data to possibly be in

error, depending on the nutrient and its con-centration range, because of this dilutionratio difference. Most clients are not aware ofthe difference in the M3 method used byArkansas (1:7 ratio) and the standard M3method used by other labs (1:10 ratio).Normally, this would not be a noteworthyproblem because the analytical result is cali-brated to a soil test range that is convertedinto a fertilizer recommendation. However,most individuals who are collecting geo-encoded soil samples are using GeographicInformation System (GIS) mapping packagesto make field assessments and produce theirown GIS-based recommendations for fertiliz-er from the lab analyses.

The objective of this work was to provide a cor-relation of M3 nutrient extraction analyses per-formed at dilution ratios of 1:7 and 1:10. Thisinformation has been developed in order to assistresearch and extension crop specialists in the task ofassessing the appropriate change that should bemade to nutrient action levels (break points) for fer-tilizer recommendations should the University ofArkansas Soil Test Lab convert to the standard 1:10M3 dilution ratio. This work was biased towardsoils representing the major crops in the ArkansasDelta agronomic region. The focal point of the ana-lytical results was in the upper-medium to lownutrient concentration ranges, which contain thenutrient action levels that are the most significantfor making fertilizer recommendation decisions.

MATERIALS AND METHODS

ReagentsThe Mehlich 3 extractant is a combination of the

following reagents:0.2N CH3COOH – 0.25N NH4NO3 – 0.015NNH4F – 0.013N HNO3 – 0.001M EDTA

R1 Ammonium Nitrate (NH4NO3) fw 80.05 g,R2 Ammonium Fluoride (NH4F) fw 37.04 g,R3 Acetic Acid, Glacial (CH3.COOH) 99.5%,

fw 60.04g, 17.4N,R4 Nitric Acid (HNO3) 68-70%, fw 63.02 g,

15.5N,R5 Ethylenediaminetetraacetic Acid (EDTA)

(HOOCCH2)2 NCH2CH2N (CH2COOH)2 fw 292.24 g.

2

AAES Special Report 205

Stock M3 Solution (3.75M NH4F – 0.25M EDTA)A calibrated 2 L volumetric flask was used to add

1200 mL of de-ionized water to 277.8 g of R2(NH4F). Then, 146.1 g of R5 (EDTA) were addedand dissolved. The volume was brought to 2 L withde-ionized water, mixed thoroughly and stored in asealed plastic container.Extractant M3 Solution

An 18 L calibrated plastic carboy was used todissolve 360 g of R1 (NH4NO3) in 14.4 L of de-ion-ized water. To this, 72 mL of Stock M3 (NH4F-EDTA) were poured and mixed. Then, 207 mL ofR3 (Acetic Acid) and 14.76 mL of R4 (HNO3) wereadded. The solution was brought to 18 L with de-ionized water and mixed thoroughly. The pH of theextractant solution was in the prescribed range of2.5+ 0.1 pH units.Extraction, 1:10 V/V Ratio

Soil samples were measured 2.0 cm3 (dried andscreened < 2 mm) into 70 mL plastic extractioncups. M3 extractant, 20 mL, was then added andplaced in a reciprocating shaker for 5 min (200, 4cm, oscillations min-1). The extractant was filteredthrough a medium porosity filter paper (Schleicher& Schuell pre-folded 11 cm grade #1 filter paper).Extraction, 1:7 V/V Ratio

This same procedure as the 1:10 extraction pro-cedure above was repeated using a 2.0 cm3 volumeof soil and 14 mL of the M3 extractant.Analytical Instrumentation

A Spectro Flame ICP (Spectro AnalyticalInstruments, 160 Authority Drive, Fitchburg, MA01420) was used to analyze the extractions from thesoil samples. The soils were analyzed for M3extractable potassium (K), calcium (Ca), sodium(Na), magnesium (Mg), iron (Fe), manganese (Mn),copper (Cu), zinc (Zn), boron (B), sulfur (S), andphosphorus (P). Analytical performance of the ICPfor the M3 method is summarized in Table 1.Soils Selected for the Summary

A representation of soil from the Arkansas Deltawas studied that exhibited a range of soil associa-tions, soil textures, and agronomic crops. Farmers,in conjunction with the local county agent, provid-ed the soil associations, soil textures, and agronom-ic crop information. Lawns, gardens, and any othersoils not associated with agronomic crops wereomitted from this study. A collection of 471 soil

samples was obtained for this review. Additionalinformation for these soils is summarized in Table 2in the Appendix.

RESULTS AND DISCUSSION

Explanation of the Graphs for Each NutrientThe results for each nutrient are illustrated as a

function of the M3 [1:7] nutrient concentrations onthe x-axis and the M3 [1:10] nutrient concentra-tions on the y-axis. A best-fit least-square equationfor a linear function was computed along with itsrespective correlation coefficient.

The same data were illustrated in a differentmanner as a second graph of the difference betweenthe M3 extractant concentrations at the 1:10 dilu-tion ratio and the 1:7 dilution ratio. The difference( [1:10] – [1:7] ) was plotted on the y-axis for eachsample (observation) on the x-axis. The mean of allthe differences is also plotted across observations asa single line on the graph. The units for the M3extractable nutrients are in pounds per acre (lb/A).Accuracy and Precision

Possible bias in the analytical results of thenutrients examined was evaluated based on a deter-mination of accuracy and precision (Table 1).Except for Na, results for the determination ofinstrument accuracy did not indicate major devia-tions that would need to be factored into the assess-ment of an element. The same was true for repeata-bility or precision. Sodium, with a negative value of13 lb/A at the high range of the analysis spectrum,was suggested to need a correction factor to accountfor ICP bias.Correlation Between the Dilution Ratio Procedures

The major cations (K, Ca, Na, and Mg) were allwell correlated between the two dilution ratio pro-cedures based on a linear function (Figs.1-4). Theslopes for these cations are all very near to unitywith y-intercepts that drive toward zero withinacceptable analytical tolerances for the objectives ofthe extraction procedure. The linear correlationsfor Fe and Mn were good, but the agreementbetween the 1:10 and 1:7 dilution ratios was posi-tively skewed for both elements (Figs. 5 and 6). Thecorrelations for Cu, Zn, S, and P were also found toagree well (Figs. 7, 8, 10, and 11). Boron was foundto have the poorest correlation, which was expectedsince the extractable levels of this element in soil are

3

A Comparative Summary of the Standard Mehlich 3 Soil Test

very near the analytical capabilities for an emissionICP (Table 1) (Fig. 9).

Average Differences Between the Dilution Ratio ProceduresThe element differences between the analytical

value of a soil sample for the 1:7 dilution ratio sub-tracted from the value of the same sample for a 1:10ratio are presented in Figures 12 through 22. Foreach element, the mean differences across all theobservations are given. The means of the differ-ences between the two extraction ratios indicatedthe 1:10 ratio to extract more nutrient in all casesexcept for B. For final assessment purposes, themean differences for the extractable nutrients wouldappear to provide a good basis for making adjust-ments from a 1:7 value to a 1:10 value. While mostof the action levels using values from the 1:7 M3method would need to be increased for all elements,P was the only nutrient that was indicated to havethe greatest relative discrepancy with a mean differ-ence of 32 lb/A.

Extractable Nutrient Levels and Soil pHRelationshipsRecent work has lead to the modification of the

Arkansas Cooperative Extension Service position onP fertility in rice (Chapman, 2000). The new P fer-tilizer recommendations for rice now consider soilpH in the decision scheme. Because of the depend-ence of the P fertilizer recommendation for rice onsoil pH, the relationships of selected extractable M3soil nutrients as a function of the 1:2 soil pH werealso examined (Figs. 23 through 28). Only a minorincreasing relationship was noted for extractable Caand soil pH (Fig. 23). Extractable Fe indicated adecreasing availability with soil pH that was poorlycorrelated (Fig. 24). No relationship with soil pHwas observed for M3 extractable Mn, Zn, and B(Figs. 25 through 27). As with the other nutrients,extractable soil P was also found not to possess anysignificant correlation with soil pH (Fig. 28). Sincethe M3 extractant is an acidic solution, it was notunexpected that the relationship between soil pHand the amount of extractable nutrient was indis-tinct due to the dissolution of various solid-phasesoluble mineral carbonates present in the soil.

4

AAES Special Report 205

Table 1. Mehlich 3 extractable elements and ICP instrument performance.Atomic Emission Emission Detection1 Accuracy2 Precision3

Element number wave length line order limit Low QC High QC (Std. Dev.)nm lbs/A lbs/A lbs/A lbs/A

K 19 766.491 1 1.9419 +1.0 -1.7 8.4Ca 20 317.933 1 0.3807 +2.8 +3.4 94.2Na 11 588.995 1 0.9747 -1.6 -13.5 11.9Mg 12 279.079 1 0.0564 +0.5 -0.4 12.0Fe 26 259.940 1 0.1269 +0.3 +1.0 8.8Mn 25 257.610 1 0.0453 +0.5 +0.9 16.4Cu 29 324.754 1 0.1140 +0.1 -0.2 0.43Zn 30 213.856 1 0.0285 +1.2 +1.4 0.89B 5 249.678 1 0.4971 -0.6 -3.8 0.32S 16 182.040 1 0.7032 +1.2 -0.7 2.8P 15 178.290 1 0.3072 +0.1 +0.3 1.5

1Element detection limits were obtained from the calculation of 3 times the standard deviation of the blank reading analysis from20 repeated measurements.

2Element accuracies were obtained from the analysis of the first two low-quality control solution standards (qc) and the first twohigh-qc standards for each month for fiscal year 1997. The low-qc solution was 17.5 lbs/A for K, Ca, Na, Mg, Fe, Mn, S, P and3.5 lb/A for Cu, Zn and 0.7 lb/A for B. The high-qc solution was 175.0 lbs/A for K, Ca, Na, Mg, Fe, Mn, S, P and 35.0 lb/A for Cu,Zn and 7.0 lb/A for B.

3Element precision assessment was obtained from the standard deviation of the mean of analyses of check-soil container num-ber 374 according to procedure outlined in Section C of UA Soil Test Lab Quality Control and Assurance Manual from April 19,1999 to April 21, 1999.

CONCLUSIONS

All of the extractable nutrients except for Bappeared to have a good linear correlation betweensamples extracted at a 1:10 dilution and a 1:7 dilu-tion ratio. No real significance was attributed to theextractable nutrients when examined as a functionof sand, silt and clay. The best method of assessingthe data appeared to be the utilization of the meanof the differences between the values for the 1:10ratio subtracted from the 1:7 ratio. These mean dif-ferences were positive for all nutrients except for B.Thus, on the average, the 1:10 dilution ratio wasfound to extract more soil nutrient. In the case of B,the M3 extractable values are too close to the ICPdetection limit to provide any solid conclusions.

LITERATURE CITED

Chapman, Stanley L. 2000. Soil test recommenda-tion guide. University of Arkansas CooperativeExtension Service. Little Rock, AR.

Donahue, S. J. 1983. Determination of phosphorusby Bray P1 extraction. p. 20-24. Reference SoilTest Methods for the Southern Region of theUnited States. Southern Cooperative SeriesBulletin 289. University of Georgia College ofAgriculture Experiment Stations. Athens, GA.

Mehlich, A. 1984. Mehlich 3 soil test extractant: Amodification of Mehlich 2 extractant.Commun. Soil Sci. Plant Anal. 15: 1409-1416.

Miller, R. O. and A. Wolf. 1998. Development of aNorth American Proficiency Testing programfor soil and plant analysis. Commun. Soil Sci.Plant Anal. 29:1685-1690.

Wolf, A. and D. E. Baker. 1985. Comparisons ofsoil test phosphorus by Olsen, Bray P1, MehlichI, and Mehlich III methods. Commun. Soil Sci.Plant Anal. 16: 467-484.

APPENDIX

Table 2. A summary of soil properties for thesamples selected for this study.

Figure 1. Correlation between the M3 soil extrac-tion for K at a 1:10 and a 1:7 dilution ratio.

Figure 2. Correlation between the M3 soil extrac-tion for Ca at a 1:10 and a 1:7 dilution ratio.

Figure 3. Correlation between the M3 soil extrac-tion for Na at a 1:10 and a 1:7 dilution ratio.

Figure 4. Correlation between the M3 soil extrac-tion for Mg at a 1:10 and a 1:7 dilution ratio.

Figure 5. Correlation between the M3 soil extrac-tion for Fe a 1:10 and a 1:7 dilution ratio.

Figure 6. Correlation between the M3 soil extrac-tion for Mn at a 1:10 and a 1:7 dilution ratio.

Figure 7. Correlation between the M3 soil extrac-tion for Cu at a 1:10 and a 1:7 dilution ratio.

Figure 8. Correlation between the M3 soil extrac-tion for Zn at a 1:10 and a 1:7 dilution ratio.

Figure 9. Correlation between the M3 soil extrac-tion for B at a 1:10 and a 1:7 dilution ratio.

Figure 10. Correlation between the M3 soil extrac-tion for S at a 1:10 and a 1:7 dilution ratio.

Figure 11. Correlation between the M3 soil extrac-tion for P at a 1:10 and a 1:7 dilution ratio.

Figure 12. Analytical differences between M3 soil Kextracted at a 1:10 and a 1:7 dilution ratio.

Figure 13. Analytical differences between M3 soilCa extracted at a 1:10 and a 1:7 dilution ratio.

Figure 14. Analytical difference between M3 soil Naextracted at a 1:10 and a 1:7 dilution ratio.

Figure 15. Analytical difference between M3 soilMg extracted at a 1:10 and a 1:7 dilution ratio.

Figure 16. Analytical differences between M3 soilFe extracted at a 1:10 and a 1:7 dilution ratio.

Figure 17. Analytical differences between M3 soilMn extracted at a 1:10 and a 1:7 dilution ratio.

Figure 18. Analytical differences between M3 soilCu extracted at a 1:10 and a 1:7 dilution ratio.

Figure 19. Analytical differences between M3 soilZn extracted at a 1:10 and a 1:7 dilution ratio.

Figure 20. Analytical differences between M3 soil Bextracted at a 1:10 and a 1:7 dilution ratio.

Figure 21. Analytical differences between M3 soil Sextracted at a 1:10 and a 1:7 dilution ratio.

5

A Comparative Summary of the Standard Mehlich 3 Soil Test

Figure 22. Analytical differences between M3 soil Pextracted at a 1:10 and a 1:7 dilution ratio.

Figure 23. Relationship between soil pH and M3extractable Ca.

Figure 24. Relationship between soil pH and M3extractable Fe.

Figure 25. Relationship between soil pH and M3extractable Mn.

Figure 26. Relationship between soil pH and M3extractable Zn.

Figure 27. Relationship between soil pH and M3extractable B.

Figure 28. Relationship between soil pH and M3extractable P.

Appendix table and figures are in the followingnumbered PDF pages.

6

AAES Special Report 205

Observation Location County Soil Associaton Texture Crop1 Star City Lincoln Perry-Portland Silt Loam Cotton2 Star City Lincoln Perry-Portland Silt Loam Cotton3 Star City Lincoln Perry-Portland Silt Loam Cotton4 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Silt Loam Cotton5 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Silt Loam Cotton6 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Silt Loam Cotton7 Paragould Greene Calloway-Henry-Grenada-Calhoun Silt Loam Grain sorghum for grain alone or not DBCP with sm. grains/non-irrig.8 Paragould Greene Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Non-irrigated9 Paragould Greene Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Non-irrigated

10 Paragould Greene Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Non-irrigated11 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton12 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton13 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton14 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton15 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton16 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton17 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton18 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton19 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton20 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton21 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton22 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton23 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton24 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton25 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton26 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton27 Pine Bluff Jefferson Rilla-Hebert Clay Loam Soybeans alone - Irrigated28 Pine Bluff Jefferson Rilla-Hebert Clay Loam Soybeans alone - Irrigated29 Pine Bluff Jefferson Rilla-Hebert Clay Loam Soybeans alone - Irrigated30 Pine Bluff Jefferson Rilla-Hebert Clay Loam Soybeans alone - Irrigated31 Pine Bluff Jefferson Rilla-Hebert Clay Loam Soybeans alone - Irrigated32 Pine Bluff Jefferson Rilla-Hebert Clay Loam Soybeans alone - Irrigated33 Pine Bluff Jefferson Rilla-Hebert Clay Loam Soybeans alone - Irrigated34 Pine Bluff Jefferson Rilla-Hebert Clay Loam Soybeans alone - Irrigated35 Pine Bluff Jefferson Rilla-Hebert Clay Loam Soybeans alone - Irrigated36 Pine Bluff Jefferson Rilla-Hebert Clay Loam Soybeans alone - Irrigated37 Pine Bluff Jefferson Rilla-Hebert Clay Loam Soybeans alone - Irrigated38 Altheimer Jefferson Rilla-Hebert Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn39 Altheimer Jefferson Rilla-Hebert Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn40 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton41 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton42 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton43 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton44 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton45 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton46 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton47 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton48 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton49 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton50 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton51 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton52 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton53 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton54 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton55 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton56 0 Crittendon Dundee-Bosket-Dubbs Silt Loam Cotton57 0 Crittendon Dundee-Bosket-Dubbs Silt Loam Cotton58 0 Crittendon Dundee-Bosket-Dubbs Silt Loam Cotton59 Altheimer Jefferson Rilla-Hebert Silt Loam Corn for grain (up to 225 bu. yield)-sandy or silt loams60 Altheimer Jefferson Rilla-Hebert Silt Loam Corn for grain (up to 225 bu. yield)-sandy or silt loams61 Altheimer Jefferson Rilla-Hebert Silt Loam Corn for grain (up to 225 bu. yield)-sandy or silt loams62 Altheimer Jefferson Rilla-Hebert Silt Loam Corn for grain (up to 225 bu. yield)-sandy or silt loams63 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 200 bu. yield)-sandy or silt loams64 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 200 bu. yield)-sandy or silt loams65 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 200 bu. yield)-sandy or silt loams66 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 200 bu. yield)-sandy or silt loams67 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 200 bu. yield)-sandy or silt loams68 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 200 bu. yield)-sandy or silt loams69 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 200 bu. yield)-sandy or silt loams70 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 200 bu. yield)-sandy or silt loams71 Harrisburg Poinsett Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Bengal72 Harrisburg Poinsett Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Bengal73 Harrisburg Poinsett Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Bengal74 Harrisburg Poinsett Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Bengal75 Harrisburg Poinsett Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Bengal76 Harrisburg Poinsett Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Bengal77 Piggott Clay-Piggott Calloway-Henry-Grenada-Calhoun Silt Loam Brambles (blackberries - raspberries)78 Lonoke Lonoke Rilla-Hebert Clay Loam Soybeans alone - Non-irrigated79 Lonoke Lonoke Rilla-Hebert Silt Loam Cotton80 Hickory Ridge Cross Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Drew81 Hickory Ridge Cross Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Drew

APPENDIX A

Table 2. A Summary of soil properties for the samples selected for this study.

Page 1

Observation Location County Soil Associaton Texture Crop82 Hickory Ridge Cross Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Drew83 Hickory Ridge Cross Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Drew84 Carlisle Lonoke Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated85 Carlisle Lonoke Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated86 Carlisle Lonoke Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated87 Carlisle Lonoke Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated88 Holly Grove Monroe Dundee-Bosket-Dubbs Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams89 Holly Grove Monroe Dundee-Bosket-Dubbs Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams90 Holly Grove Monroe Dundee-Bosket-Dubbs Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams91 Holly Grove Monroe Dundee-Bosket-Dubbs Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams92 Holly Grove Monroe Dundee-Bosket-Dubbs Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams93 Holly Grove Monroe Dundee-Bosket-Dubbs Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams94 0 Poinsett Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated95 0 Poinsett Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated96 0 Poinsett Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated97 0 Poinsett Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated98 Taylor Lafayette Wrightsville-Louin-Acadia Silt Loam Soybeans alone - Non-irrigated99 Osceola Mississippi-Blythev Commerce-Sharkey-Crevasse-Robinsonvil Silt Loam Cotton

100 Osceola Mississippi-Blythev Commerce-Sharkey-Crevasse-Robinsonvil Silt Loam Cotton101 England Lonoke Perry-Portland Clay Loam Soybeans alone - Irrigated102 England Lonoke Perry-Portland Clay Loam Soybeans alone - Irrigated103 England Lonoke Perry-Portland Clay Loam Soybeans alone - Irrigated104 England Lonoke Perry-Portland Clay Loam Soybeans alone - Irrigated105 England Lonoke Perry-Portland Clay Loam Soybeans alone - Irrigated106 Austin Lonoke Loring Silt Loam Blueberries - 4th year or older107 Austin Lonoke Loring Silt Loam Blueberries - 4th year or older108 Austin Lonoke Loring Silt Loam Blueberries - 4th year or older109 Lonoke Lonoke Rilla-Hebert Clay Rice - Bengal110 Lonoke Lonoke Rilla-Hebert Sand Rice - Bengal111 Lonoke Lonoke Rilla-Hebert Clay Rice - Bengal112 Lonoke Lonoke Crowley-Stuttgart Silt Loam Rice - Drew113 Hamburg Ashley Calloway-Henry-Grenada-Calhoun Silt Loam Oats for grain114 Hamburg Ashley Calloway-Henry-Grenada-Calhoun Silt Loam Oats for grain115 Hamburg Ashley Calloway-Henry-Grenada-Calhoun Silt Loam Oats for grain116 Hamburg Ashley Calloway-Henry-Grenada-Calhoun Silt Loam Oats for grain117 Bartlett Poinsett Sharkey-Alligator-Tunica Clay Loam Soybeans alone - Irrigated118 Bartlett Poinsett Sharkey-Alligator-Tunica Silt Loam Soybeans alone - Irrigated119 England Lonoke Rilla-Hebert Silt Loam Soybeans alone - Irrigated120 Lonoke Lonoke Crowley-Stuttgart Silt Loam Rice - Lagrue121 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Cotton122 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Cotton123 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Cotton124 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Cotton125 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Cotton126 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Cotton127 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Cotton128 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Cotton129 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Cotton130 Altheimer Jefferson Rilla-Hebert Silt Loam Corn for grain (up to 160 bu/A yield)-clay loams, silty clays, clays131 Altheimer Jefferson Rilla-Hebert Silt Loam Corn for grain (up to 160 bu/A yield)-clay loams, silty clays, clays132 Altheimer Jefferson Rilla-Hebert Silt Loam Corn for grain (up to 160 bu/A yield)-clay loams, silty clays, clays133 Altheimer Jefferson Rilla-Hebert Silt Loam Corn for grain (up to 160 bu/A yield)-clay loams, silty clays, clays134 Altheimer Jefferson Rilla-Hebert Silt Loam Corn for grain (up to 160 bu/A yield)-clay loams, silty clays, clays135 Altheimer Jefferson Rilla-Hebert Silt Loam Cotton136 Altheimer Jefferson Rilla-Hebert Silt Loam Cotton137 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton138 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton139 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton140 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton141 Pine Bluff Jefferson Severn-Oklared Silt Loam Cotton142 Hoxie Lawrence Foley-Jackport-Crowley Silt Loam Soybeans alone - Non-irrigated143 Hoxie Lawrence Foley-Jackport-Crowley Silt Loam Soybeans alone - Non-irrigated144 Hoxie Lawrence Foley-Jackport-Crowley Silt Loam Soybeans alone - Non-irrigated145 Alicia Lawrence Foley-Jackport-Crowley Silt Loam Soybeans alone - Non-irrigated146 Maumelle Pulaski Perry-Portland Clay Loam Cotton147 Maumelle Pulaski Perry-Portland Clay Loam Cotton148 Maumelle Pulaski Perry-Portland Clay Loam Cotton149 Maumelle Pulaski Perry-Portland Clay Loam Cotton150 Maumelle Pulaski Perry-Portland Clay Loam Cotton151 0 Prairie-Des Arc Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated152 0 Prairie-Des Arc Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated153 0 Prairie-Des Arc Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated154 0 Prairie-Des Arc Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated155 0 Prairie-Des Arc Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated156 0 Prairie-Des Arc Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated157 0 Prairie-Des Arc Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated158 0 Prairie-Des Arc Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated159 0 Prairie-Des Arc Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated160 Des Arc Prairie Kobel Clay Loam Soybeans DBLCRP after wheat following any other crop - irrig.161 Texarkana Miller Billyhaw-Perry Silt Loam Soybeans alone - Non-irrigated162 Texarkana Miller Billyhaw-Perry Silt Loam Soybeans alone - Non-irrigated163 Altheimer Jefferson Rilla-Hebert Silt Loam Cotton164 Altheimer Jefferson Rilla-Hebert Silt Loam Cotton165 Forrest City St. Francis Loring-Memphis Silt Loam Corn for grain (up to 150 bu. yield)-sandy or silt loams

Page 2

Observation Location County Soil Associaton Texture Crop166 Paragould Greene Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Non-irrigated167 Wynne Cross Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated168 Wynne Cross Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated169 Wynne Cross Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated170 Wynne Cross Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated171 Biscoe Prairie Dundee-Bosket-Dubbs Silt Loam Cotton172 Biscoe Prairie Dundee-Bosket-Dubbs Silt Loam Cotton173 Biscoe Prairie Dundee-Bosket-Dubbs Silt Loam Cotton174 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties175 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties176 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties177 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties178 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties179 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties180 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties181 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties182 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties183 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties184 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties185 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties186 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties187 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties188 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties189 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties190 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties191 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties192 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties193 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties194 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties195 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties196 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties197 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties198 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties199 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties200 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties201 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties202 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties203 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties204 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties205 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties206 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties207 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties208 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties209 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties210 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties211 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties212 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties213 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties214 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties215 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties216 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties217 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties218 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties219 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties220 Lonoke Lonoke Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Other varieties221 Jacksonville Lonoke Perry-Portland Clay Loam Apple, peach, or plum trees - 3rd year or leaf222 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Cotton223 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Cotton224 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Cotton225 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Cotton226 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Cotton227 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Cotton228 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Cotton229 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Cotton230 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Cotton231 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated232 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated233 Turner Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated234 Holly Grove Monroe Calloway-Henry-Grenada-Calhoun Silt Loam Grain sorghum for grain alone or not DBCP with sm. grains/irrig.235 Holly Grove Monroe Calloway-Henry-Grenada-Calhoun Silt Loam Grain sorghum for grain alone or not DBCP with sm. grains/irrig.236 Holly Grove Monroe Calloway-Henry-Grenada-Calhoun Silt Loam Grain sorghum for grain alone or not DBCP with sm. grains/irrig.237 Holly Grove Monroe Calloway-Henry-Grenada-Calhoun Silt Loam Grain sorghum for grain alone or not DBCP with sm. grains/irrig.238 Holly Grove Monroe Calloway-Henry-Grenada-Calhoun Silt Loam Grain sorghum for grain alone or not DBCP with sm. grains/irrig.239 0 Poinsett Dundee-Bosket-Dubbs Sand Cotton240 0 Poinsett Dundee-Bosket-Dubbs Sand Cotton241 0 Poinsett Dundee-Bosket-Dubbs Sand Cotton242 0 Poinsett Dundee-Bosket-Dubbs Sand Cotton243 Desha Independence Amagon-Dundee Silt Loam Corn for grain (up to 125 bu. yield)-sandy or silt loams244 Desha Independence Amagon-Dundee Silt Loam Corn for grain (up to 125 bu. yield)-sandy or silt loams245 Desha Independence Amagon-Dundee Silt Loam Soybeans DBLCRP after wheat/wheat follows sorghum, rice or corn246 Desha Independence Amagon-Dundee Silt Loam Corn for grain (up to 125 bu. yield)-sandy or silt loams247 Batesville Independence Amagon-Dundee Silt Loam Soybeans DBLCRP after wheat/wheat follows sorghum, rice or corn248 Batesville Independence Amagon-Dundee Silt Loam Soybeans DBLCRP after wheat/wheat follows sorghum, rice or corn249 Dumas Lincoln Perry-Portland Silt Loam Soybeans alone - Irrigated

Page 3

Observation Location County Soil Associaton Texture Crop250 Dumas Lincoln Perry-Portland Silt Loam Soybeans alone - Irrigated251 Dumas Lincoln Perry-Portland Silt Loam Soybeans alone - Irrigated252 Dumas Lincoln Perry-Portland Silt Loam Soybeans alone - Irrigated253 Keiser Mississippi-Blythev Amagon-Dundee Clay Cotton254 Keiser Mississippi-Blythev Amagon-Dundee Clay Loam Cotton255 Keiser Mississippi-Blythev Amagon-Dundee Clay Loam Cotton256 Keiser Mississippi-Blythev Amagon-Dundee Clay Cotton257 Gillett Arkansas-Dewitt Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated258 Gillett Arkansas-Dewitt Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated259 Gillett Arkansas-Dewitt Crowley-Stuttgart Silt Loam Rice - Lagrue260 Lake Village Chicot Commerce-Sharkey-Crevasse-Robinsonvil Clay Soybeans alone - Irrigated261 Lake Village Chicot Commerce-Sharkey-Crevasse-Robinsonvil Clay Soybeans alone - Irrigated262 Lake Village Chicot Commerce-Sharkey-Crevasse-Robinsonvil Clay Soybeans alone - Irrigated263 Pine Bluff Jefferson Rilla-Hebert Silt Loam Rice - Cypress264 Bradley Lafayette Severn-Oklared Silt Loam Cotton265 Bradley Lafayette Severn-Oklared Silt Loam Cotton266 Bradley Lafayette Severn-Oklared Silt Loam Corn for grain (up to 150 bu. yield)-sandy or silt loams267 Bradley Lafayette Severn-Oklared Silt Loam Corn for grain (up to 150 bu. yield)-sandy or silt loams268 Bradley Lafayette Severn-Oklared Silt Loam Cotton269 Bradley Lafayette Severn-Oklared Silt Loam Cotton270 Bradley Lafayette Severn-Oklared Silt Loam Soybeans alone - Non-irrigated271 Bradley Lafayette Severn-Oklared Silt Loam Soybeans alone - Non-irrigated272 Bradley Lafayette Severn-Oklared Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn273 Bradley Lafayette Severn-Oklared Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn274 Bradley Lafayette Severn-Oklared Silt Loam Corn for grain (up to 150 bu. yield)-sandy or silt loams275 Bradley Lafayette Severn-Oklared Silt Loam Corn for grain (up to 150 bu. yield)-sandy or silt loams276 Bradley Lafayette Severn-Oklared Silt Loam Cotton277 Bradley Lafayette Severn-Oklared Silt Loam Cotton278 Bradley Lafayette Severn-Oklared Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn279 Bradley Lafayette Severn-Oklared Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn280 Scott Pulaski Perry-Portland Silt Loam Soybeans alone - Irrigated281 Scott Pulaski Perry-Portland Silt Loam Soybeans alone - Irrigated282 Scott Pulaski Perry-Portland Silt Loam Soybeans alone - Irrigated283 Gillett Arkansas-Dewitt Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated284 Gillett Arkansas-Dewitt Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated285 Hamburg Ashley Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated286 Hamburg Ashley Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated287 Hamburg Ashley Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated288 Joiner Mississippi-OsceolaCommerce-Sharkey-Crevasse-Robinsonvil Silt Loam Cotton289 Joiner Mississippi-OsceolaCommerce-Sharkey-Crevasse-Robinsonvil Silt Loam Cotton290 Bradley Lafayette Severn-Oklared Silt Loam Cotton291 Bradley Lafayette Severn-Oklared Silt Loam Cotton292 Bradley Lafayette Severn-Oklared Silt Loam Soybeans alone - Non-irrigated293 Batesville Independence Amagon-Dundee Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn294 Bradley Lafayette Severn-Oklared Silt Loam Cotton295 Bradley Lafayette Severn-Oklared Silt Loam Cotton296 Bradley Lafayette Severn-Oklared Silt Loam Cotton297 Bradley Lafayette Severn-Oklared Silt Loam Cotton298 Aubrey Lee Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams299 Aubrey Lee Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams300 Aubrey Lee Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams301 Aubrey Lee Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams302 Aubrey Lee Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams303 Aubrey Lee Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams304 Aubrey Lee Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams305 Aubrey Lee Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams306 Aubrey Lee Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams307 Aubrey Lee Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 175 bu. yield)-sandy or silt loams308 Stuttgart Arkansas-Stuttgart Crowley-Stuttgart Silt Loam Pecan trees - 5th year or older (orchard)309 Pollard Lawrence Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated310 Pollard Lawrence Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated311 Pollard Lawrence Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated312 Pollard Lawrence Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated313 Reyno Lawrence Foley-Jackport-Crowley Sand Soybeans alone - Irrigated314 Oneida Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated315 Oneida Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated316 Bradley Lafayette Severn-Oklared Silt Loam Cotton317 Bradley Lafayette Severn-Oklared Silt Loam Cotton318 Bradley Lafayette Severn-Oklared Silt Loam Cotton319 Bradley Lafayette Severn-Oklared Silt Loam Cotton320 Bradley Lafayette Severn-Oklared Silt Loam Cotton321 Bradley Lafayette Severn-Oklared Silt Loam Cotton322 Bradley Lafayette Severn-Oklared Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn323 Bradley Lafayette Severn-Oklared Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn324 Bradley Lafayette Severn-Oklared Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn325 Bradley Lafayette Severn-Oklared Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn326 Brinkley Lonoke Foley-Jackport-Crowley Silt Loam Wheat for grain327 McCrory Woodruff Dundee-Bosket-Dubbs Silt Loam Soybeans alone - Irrigated328 McCrory Woodruff Dundee-Bosket-Dubbs Silt Loam Soybeans alone - Irrigated329 DeWitt Arkansas-Dewitt Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated330 DeWitt Arkansas-Dewitt Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated331 DeWitt Arkansas-Dewitt Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated332 Greenway Clay-Piggott Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Non-irrigated333 Marianna Lee Loring-Memphis Silt Loam Soybeans alone - Non-irrigated

Page 4

Observation Location County Soil Associaton Texture Crop334 Hickory Ridge Cross Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated335 Hickory Ridge Cross Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated336 Hickory Ridge Cross Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated337 Walnut Ridge Lawrence Foley-Jackport-Crowley Silt Loam Rice - Kaybonnet338 Paragould Greene Loring-Memphis Silt Loam Wheat for grain339 Star City Lincoln Perry-Portland Silt Loam Soybeans alone - Non-irrigated340 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Corn for grain (up to 150 bu. yield)-sandy or silt loams341 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Non-irrigated342 Jonesboro Craighead Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated343 Jonesboro Craighead Dundee-Bosket-Dubbs Clay Loam Soybeans alone - Irrigated344 Jonesboro Craighead Dundee-Bosket-Dubbs Clay Loam Corn for grain (up to 120 bu/A yield)-clay loams, silty clays, clays345 Plumerville Conway Perry-Portland Silt Loam Soybeans alone - Non-irrigated346 Plumerville Conway Perry-Portland Silt Loam Soybeans alone - Non-irrigated347 Jonesboro Craighead Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Irrigated348 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Fig trees - 2nd year or leaf349 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Fig trees - 2nd year or leaf350 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Drew351 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Drew352 Beech Grove Greene Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated353 Beech Grove Greene Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated354 Beech Grove Greene Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated355 Hoxie Lawrence Foley-Jackport-Crowley Silt Loam Soybeans DBLCRP after wheat/wheat not fol. sorghum, rice or corn356 Corning Clay-Corning Kobel Clay Wheat for grain357 Corning Clay-Corning Kobel Clay Wheat for grain358 Corning Clay-Corning Kobel Clay Wheat for grain359 Hunter Woodruff Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated360 England Lonoke Rilla-Hebert Silt Loam Pecan trees - 5th year or older (orchard)361 Star City Lincoln Perry-Portland Silt Loam Soybeans alone - Irrigated362 Star City Lincoln Perry-Portland Silt Loam Soybeans alone - Irrigated363 Jonesboro Lawrence Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated364 Hoxie Lawrence Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated365 Paragould Greene Kobel Silt Loam Soybeans alone - Irrigated366 Paragould Greene Kobel Silt Loam Soybeans alone - Irrigated367 Coushatta Lafayette Severn-Oklared Silt Loam Cotton368 Coushatta Lafayette Severn-Oklared Silt Loam Cotton369 Coushatta Lafayette Billyhaw-Perry Clay Loam Cotton370 Coushatta Lafayette Billyhaw-Perry Clay Loam Cotton371 Coushatta Lafayette Severn-Oklared Silt Loam Soybeans alone - Non-irrigated372 Coushatta Lafayette Severn-Oklared Silt Loam Soybeans alone - Non-irrigated373 Coushatta Lafayette Severn-Oklared Silt Loam Soybeans alone - Non-irrigated374 Coushatta Lafayette Severn-Oklared Silt Loam Soybeans alone - Non-irrigated375 Coushatta Lafayette Billyhaw-Perry Clay Loam Soybeans alone - Non-irrigated376 Coushatta Lafayette Billyhaw-Perry Clay Loam Soybeans alone - Non-irrigated377 Coushatta Lafayette Severn-Oklared Silt Loam Soybeans alone - Non-irrigated378 Coushatta Lafayette Severn-Oklared Silt Loam Soybeans alone - Non-irrigated379 Coushatta Lafayette Severn-Oklared Silt Loam Soybeans alone - Non-irrigated380 Coushatta Lafayette Severn-Oklared Silt Loam Soybeans alone - Non-irrigated381 Coushatta Lafayette Severn-Oklared Sand Soybeans alone - Non-irrigated382 Coushatta Lafayette Severn-Oklared Sand Soybeans alone - Non-irrigated383 Portland Chicot Perry-Portland Clay Soybeans alone - Irrigated384 Portland Chicot Perry-Portland Clay Rice - Cypress385 Beech Grove Greene Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated386 Beech Grove Greene Foley-Jackport-Crowley Silt Loam Soybeans alone - Irrigated387 Bono Greene Kobel Silt Loam Soybeans alone - Irrigated388 Gillett Arkansas-Dewitt Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated389 Gillett Arkansas-Dewitt Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated390 Gillett Arkansas-Dewitt Crowley-Stuttgart Silt Loam Soybeans alone - Irrigated391 Forrest City St. Francis Calloway-Henry-Grenada-Calhoun Clay Loam Soybeans alone - Irrigated392 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Non-irrigated393 Marianna Lee Calloway-Henry-Grenada-Calhoun Silt Loam Soybeans alone - Non-irrigated394 Lake Village Chicot Sharkey-Alligator-Tunica Silt Loam Soybeans alone - Irrigated395 Wynne Cross Calloway-Henry-Grenada-Calhoun Silt Loam Rice - Drew396 Lake Village Chicot Commerce-Sharkey-Crevasse-Robinsonvil Clay Rice - Cypress397 Texarkana Miller Sacul-Smithdale-Sawyer Silt Loam Wheat for grazing plus grain398 Texarkana Miller Sacul-Smithdale-Sawyer Silt Loam Wheat for grazing plus grain399 Harrisbrug Poinsett Dundee-Bosket-Dubbs Silt Loam Rice - Drew400 Harrisburg Poinsett Dundee-Bosket-Dubbs Silt Loam Rice - Drew401 Buckner Lafayette Sacul-Smithdale-Sawyer Silt Loam Corn for grain (up to 125 bu. yield)-sandy or silt loams402 Buckner Lafayette Sacul-Smithdale-Sawyer Silt Loam Corn for grain (up to 125 bu. yield)-sandy or silt loams403 Buckner Lafayette Sacul-Smithdale-Sawyer Silt Loam Corn for grain (up to 125 bu. yield)-sandy or silt loams404 Buckner Lafayette Sacul-Smithdale-Sawyer Silt Loam Corn for grain (up to 125 bu. yield)-sandy or silt loams405 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer406 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer407 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer408 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer409 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer410 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer411 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer412 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer413 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer414 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer415 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer416 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer417 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer

Page 5

Observation Location County Soil Associaton Texture Crop418 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer419 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer420 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer421 Lexa Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Bermudagrass - maintenance422 Lexa Phillips Calloway-Henry-Grenada-Calhoun Silt Loam Bermudagrass - maintenance423 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer424 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer425 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer426 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer427 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer428 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer429 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer430 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer431 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer432 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer433 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer434 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer435 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer436 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer437 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer438 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer439 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer440 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer441 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer442 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer443 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer444 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer445 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer446 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer447 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer448 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer449 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer450 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer451 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer452 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer453 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer454 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer455 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer456 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer457 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer458 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer459 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer460 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer461 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer462 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer463 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer464 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer465 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer466 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer467 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer468 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer469 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer470 Pine Bluff Jefferson Rilla-Hebert Silt Loam Peas - Southern or summer471 Stuttgart Arkansas-Stuttgart Crowley-Stuttgart Silt Loam Pecan trees - 5th year or older (orchard)

Page 6

AAES Special Report 205

APPENDIX A

Page 7

Figure 1. Correlation between the M3 soil extraction for K at a 1:10 and a 1:7 dilution ratio.

Figure 2. Correlation between the M3 soil extraction for Ca at a 1:10 and a 1:7 dilution ratio.

0

200

400

600

800

1000

1200

0 200 400 600 800 1000 1200

1:7 M3 Extractable K, lbs/A

1:10

M3

Extra

ctab

le K

, lbs

/A

Silt

Clay

Sand

Trendline

y = 1.0192x + 5.3543 R2 = 0.96n = 469

0

2000

4000

6000

8000

10000

12000

0 2000 4000 6000 8000 10000 12000

1:7 M3 Extractable Ca, lbs/A

1:10

M3

Extra

ctab

le C

a, lb

s/A

Silt

Clay

Sand

Trendline

y = 1.1255x + 48.35 R2 = 0.95n = 470

AAES Special Report 205

APPENDIX A

Page 8

Figure 3. Correlation between the M3 soil extraction for Na at a 1:10 and a 1:7 dilution ratio.

Figure 4. Correlation between the M3 soil extraction for Mg at a 1:10 and a 1:7 dilution ratio.

0

100

200

300

400

500

0 100 200 300 400 500

1:7 M3 Extractable Na, lbs/A

1:10

M3

Extra

ctab

le N

a, lb

s/A

Silt

Clay

Sand

Trendline

y = 1.0266x + 6.7167 R2 = 0.96n = 471

0

400

800

1200

1600

2000

2400

2800

0 400 800 1200 1600 2000 2400 2800

1:7 M3 Extractable Mg, lbs/A

1:10

M3

Extra

ctab

le M

g, lb

s/A

Silt

Clay

Sand

Trendline

y = 1.0266x + 11.747 R2 = 0.98n = 471

AAES Special Report 205

APPENDIX A

Page 9

Figure 5. Correlation between the M3 soil extraction for Fe a 1:10 and a 1:7 dilution ratio.

Figure 6. Correlation between the M3 soil extraction for Mn at a 1:10 and a 1:7 dilution ratio.

-200

0

200

400

600

800

1000

1200

1400

0 100 200 300 400 500 600 700

1:7 M3 Extractable Fe, lbs/A

1:10

M3

Extra

ctab

le F

e, lb

s/A

Silt

Clay

Sand

Trendline

y = 1.921x - 42.518 R2 = 0.81n = 471

-200

0

200

400

600

800

1000

1200

1400

0 100 200 300 400 500 600

1:7 M3 Extractable Mn, lbs/A

1:10

M3

Extra

ctab

le M

n, lb

s/A

Silt

Clay

Sand

Trendline

y = 2.4076x - 18.503 R2 = 0.90n = 471

AAES Special Report 205

APPENDIX A

Page 10

Figure 7. Correlation between the M3 soil extraction for Cu at a 1:10 and a 1:7 dilution ratio.

Figure 8. Correlation between the M3 soil extraction for Zn at a 1:10 and a 1:7 dilution ratio.

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0.0 5.0 10.0 15.0 20.0 25.0 30.0

1:7 M3 Extractable Cu, lbs/A

1:10

M3

Extra

ctab

le C

u, lb

s/A

Silt

Clay

Sand

Trendline

y = 1.3558x + 0.7238 R2 = 0.84n = 471

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.01:7 M3 Extractable ZN, lbs/A

1:10

M3

Extra

ctab

le Z

n, lb

s/A

Silt

Clay

Sand

Trendline

y = 1.218x + 1.2249 R2 =0.93n =470

AAES Special Report 205

APPENDIX A

Page 11

Figure 9. Correlation between the M3 soil extraction for B at a 1:10 and a 1:7 dilution ratio.

Figure 10. Correlation between the M3 soil extraction for S at a 1:10 and a 1:7 dilution ratio.

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0

1:7 M3 Extractable B, lbs/A

1:10

M3

Extra

ctab

le B

, lbs

/A

SiltClaySandTrendline

y = 0.5898x + 0.2165 R2 = 0.31n = 468

0

50

100

150

200

250

0 20 40 60 80 100 120 140 160

1:7 M3 Extractable S, lbs/A

1:10

M3

Extra

ctab

le S

, lbs

/A

Silt

Clay

Sand

Trendline

y = 1.1704x + 18.541 R2 = 0.93n = 468

AAES Special Report 205

APPENDIX A

Page 12

Figure 11. Correlation between the M3 soil extraction for P at a 1:10 and a 1:7 dilution ratio.

0

50

100

150

200

250

300

0 20 40 60 80 100 120 140 160 180 200

1:7 M3 Extractable P, lbs/A

1:10

M3

Extra

ctab

le P

, lbs

/A

Silt

Clay

Sand

Trendline

y = 1.2655x + 14.852 R2 = 0.92n = 460

AAES Special Report 205

APPENDIX A

Page 13

Figure 12. Analytical differences between M3 soil K extracted at a 1:10 and a 1:7 dilution ratio.

Figure 13. Analytical differences between M3 soil Ca extracted at a 1:10 and a 1:7 dilution ratio.

-150

-100

-50

0

50

100

150

200

0 50 100 150 200 250 300 350 400 450 500

Observations

M3

(1:1

0 K)

- (1

:7 K

), lb

s/A

Mean = 10

-1000

-500

0

500

1000

1500

2000

2500

3000

3500

4000

0 50 100 150 200 250 300 350 400 450 500

Observations

M3

(1:1

0 C

a) -

(1:7

Ca)

, lbs

/A

Mean = 344

AAES Special Report 205

APPENDIX A

Page 14

Figure 14. Analytical difference between M3 soil Na extracted at a 1:10 and a 1:7 dilution ratio.

Figure 15. Analytical difference between M3 soil Mg extracted at a 1:10 and a 1:7 dilution ratio.

-120

-80

-40

0

40

80

120

160

0 50 100 150 200 250 300 350 400 450 500

Observations

M3

(1:1

0 N

a) -

(1:7

Na)

, lbs

/A

Mean = 9

-200

-100

0

100

200

300

400

500

0 50 100 150 200 250 300 350 400 450 500

Observations

M3

(1:1

0 M

g) -

(1:7

Mg)

, lbs

/A

Mean = 50

AAES Special Report 205

APPENDIX A

Page 15

Figure 16. Analytical differences between M3 soil Fe extracted at a 1:10 and a 1:7 dilution ratio.

Figure 17. Analytical differences between M3 soil Mn extracted at a 1:10 and a 1:7 dilution ratio.

0

100

200

300

400

500

600

700

800

900

0 50 100 150 200 250 300 350 400 450 500

Observations

M3

(1:1

0 Fe

) - (1

:7 F

e), l

bs/A

Mean = 245

0

100

200

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400 450 500

Observations

M3

(1:1

0 M

n) -

(1:7

Mn)

, lbs

/A

Mean = 170

AAES Special Report 205

APPENDIX A

Page 16

Figure 18. Analytical differences between M3 soil Cu extracted at a 1:10 and a 1:7 dilution ratio.

Figure 19. Analytical differences between M3 soil Zn extracted at a 1:10 and a 1:7 dilution ratio.

-2.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

0 50 100 150 200 250 300 350 400 450 500

Observations

M3

(1:1

0 C

u) -

(1:7

Cu)

, lbs

/A

Mean = 1.8

-10

0

10

20

30

0 50 100 150 200 250 300 350 400 450 500

Observations

M3

(1:1

0 Zn

) - (1

:7 Z

n), l

bs/A

Mean = 2.4

AAES Special Report 205

APPENDIX A

Page 17

Figure 20. Analytical differences between M3 soil B extracted at a 1:10 and a 1:7 dilution ratio.

Figure 21. Analytical differences between M3 soil S extracted at a 1:10 and a 1:7 dilution ratio.

0

1

2

3

4

0 50 100 150 200 250 300 350 400 450 500

Observations

M3

(1:1

0 B)

- (1

:7 B

), lb

s/A

Mean = 0.0

0

10

20

30

40

50

60

0 50 100 150 200 250 300 350 400 450 500

Observations

M3

(1:1

0 S)

- (1

:7 S

), lb

s/A

Mean = 21

AAES Special Report 205

APPENDIX A

Page 18

Figure 22. Analytical differences between M3 soil P extracted at a 1:10 and a 1:7 dilution ratio.

0

25

50

75

100

125

0 50 100 150 200 250 300 350 400 450 500

Observations

M3

Extra

ctab

le (1

:10

P) -

(1:7

P),

lbs/

AMean = 32

AAES Special Report 205

APPENDIX A

Page 19

Figure 23. Relationship between soil pH and M3 extractable Ca.

y = 0.0002x + 5.5046 R2 = 0.3251

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000

1:7 Ca, lbs/A

1:2

pH

n = 471

Figure 24. Relationship between soil pH and M3 extractable Fe.

y = -0.0019x + 6.6425 R2 = 0.0903

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

0 100 200 300 400 500 600 700

1:7 Fe, lbs/A

1:2

pH

n = 471

AAES Special Report 205

APPENDIX A

Page 20

Figure 25. Relationship between soil pH and M3 extractable Mn.

y = 0.0003x + 6.0239 R2 = 0.0017

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

0 50 100 150 200 250 300 350 400 450 500 550

1:7 Mn, lbs/A

1:2

pH

n = 471

Figure 26. Relationship between soil pH and M3 extractable Zn.

y = 0.0065x + 6.0306 R2 = 0.0038

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0

1:7 Zn, lbs/A

1:2

pH

n = 471

AAES Special Report 205

APPENDIX A

Page 21

Figure 27. Relationship between soil pH and M3 extractable B.

y = 0.0062x + 6.0228 R2 = 0.0256

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

0 50 100 150 200 250 3001:7 B, lbs/A

1:2

wat

er p

H

n = 471

Figure 28. Relationship between soil pH and M3 extractable P.

y = -0.0006x + 6.1093 R2 = 0.0054

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

0 200 400 600 800 1000 1200

1:7 P, lbs/A

1:2

pH

n = 471