Interpretations of soil analysis
AND
MANUAL RECOMMENDATIONS
INTRODUCTION
This manual contains information concerning interpretations of soil testing and fertilizer
suggestions limestone used by the University of Missouri soil testing service. This information
used with chemical soil tests currently used by the University of Missouri soil testing laboratories.
This manual is designed to help people familiar with the analysis of soil Missouri
program to draw interpretations and proposed treatments based on soil test levels.
The main contributors to this guide include Daryl D. Buchholz, James R. Brown, Roger
G. Hanson, N. Howell Wheaton, John D. Garrett, Robin R. Rodriguez, Don Backfisch, John
Lory, Peter Scharf and Manjula Nathan.
Figures 1, 2 and 3 are the front and back of the record of the soil (MP-188) and
Soil Test Report Form (MP-189) currently used.
Various other sources should be consulted for a more detailed discussion of the analysis of soil
interpretations and information on soil testing program in Missouri. These sources include:
Fisher, T. R. 1974. Some thoughts on the interpretation of soil
Tests for phosphorus and potassium. Missouri Agricultural Experiment
Research Station Bulletin No. 1007.
Brown, J. R., R. G. Hanson and D. D. Buchholz. 1980. Interpretations
Missouri soil test results. University of Missouri Agronomy
Department Miscellaneous Publication 80-04.
Brown, R. J. and Robin R. Rodriguez. 1982. Soil analysis in
Missouri. University of Missouri Extension Circular 923.
using the computer programming through Deanna Crocker, Michael Hess,
Ken Kuebler, Mark Gardner and Richard Ahrens.
The author also wishes to thank the many members of the Department of Agronomy
who were involved in various ways to help establish useful soil analyzes
interpretations and suggested fertilizer and lime application rates.
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2
Nitrogen
Soil analysis
Nitrogen is mobile in soil nutrient. Almost all soils in Missouri need nitrogen for
optimal production of crops requiring nitrogen uptake. The soil test used to estimate
nitrogen is supplied test organic matter. Tweaks nitrogen are also made on
Based on the texture and the time of year that the majority of the growth of the crop takes place soil.
Table I provides an overview of the soil nitrogen supplying power for almost all row crop and small grain.
The evaluation system
The soils are not evaluated on the basis of organic matter content. This is because the rapid changes in
organic matter does not occur in the normal crop management. As can be seen, the soil containing
larger amounts of organic matter are usually able to release higher amounts of nitrogen.
Recommendations
A. Drilling
recommendations of nitrogen on forage crops are usually not set on the basis
organic matter. Legumes fix their own nitrogen and, therefore, in general, have not
recommendations for additional nitrogen fertilizer. Table II shows the nitrogen recommendation
Equations used for forage crops which do not require nitrogen. Not specified crops have nitrogen
requirement.
B. row crops and small grains
nitrogen requirements for a culture are determined on the need to produce vegetation and
portions of grains. Crop needs nitrogen on a per unit basis are given in Table III. Total
nitrogen requirements are calculated using the equation:
NR = (Vm) (Nv) + (YG) (Ng)
Where: NR = total nitrogen requirements
Vm = kilos of plant material per acre
Nv = pounds of nitrogen per kilogram of plant material
YG = yield goal
Ng = pounds of nitrogen per unit of production (cereals)
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3
nitrogen requirements (NR) less nitrogen supplying power of the soil (Table I)
based on the organic content of nitrogen shows the rate required to produce output
Aim for the selected crop.
Table IV shows the nitrogen calculations used for each line or small grain harvest in obtaining
nitrogen requirements.
Cotton (code of culture 102) nitrogen recommendations are not dependent on organic
important, but the texture of the soil, as indicated by the cation exchange capacity. The equation used
to determine the nitrogen recommendations on cotton is as follows:
NR = 0.1 * (yield - 500) + 50 + CEC
with the limits of the lowest recommended dose is 50 pounds of nitrogen per acre. No
adjustment is made on the basis of soil organic matter.
Corn (code 103 cultures) nitrogen requirements are adjusted on the basis of the performance target and
the assumed population required to achieve a given level of performance. These populations are also
follows:
----------- ------------------------------ Irrigated Dryland
Yield Yield Lens Population Population
bu / a plants / drank / a plant / a
<60 14 000 <20000140
60-99 16.000 23.000 140-179
100-119 18,000 180-219 26,000
120-139 20,000 220-259 29,000
140-169 22,000> 260 32 000
> 170 25 000
The total nitrogen needs can be determined using the basic equation:
NR = (people / acre) x (4 lb N/1000 plants) + (0.9 lb N / bu) x (Performance Goal)
This requirement of total nitrogen must then be reduced depending on the nitrogensupplying
power of the soil (Table I).
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4
Table I. adjustments of nitrogen according to the soil texture and organic matter rate
for grains in the hot season and row crops.
Cation exchange soil organic N
Soil texture capacity for credit
meq/100g (%) lbs. N / A
<0.5 20
Sand - OM 0.6 to 1.4 x 40
Sandy loam <10
1.5 ≥ 60
<2.0 40
Loam - 02.01 to 03.09 x 20 OM
Loam 10-18
> 4.0 80
<2.0 20
Clay Loam - Clay> 18 02.01 to 04.09 x 10 OM
> 5.0 50
5
Table II. Equations to determine the nitrogen requirements of forage crops
Crop Crop code N recommendation equation
1 alfalfa, alfalfa - Grass Establishment
3 clover - Grass establishment Lbs organic matter. N / acre
<2.0% 30
≥ 2.0 20
4 cold season grass establishment <1.9% 40
2.0 - 2.9 30%
> 3/0 20%
8 Wildlife food plot 117 - Adjustment OM
9 creation of Bermudagrass <1.9% 40
2.0 - 2.9 30%
> 3/0 20%
13 Bluegrass Pasture (performance target) x (0.6 # N Day / cow)
14 Bermudagrass Hay (performance target) x (50 N / Ton)
15 Grazing Bermudagrass (performance target) x (0.6 # N Day / cow)
18 cold season Grass Hay (performance target) x (40 N / Ton)
19 cool season grass pasture (performance target) x (0.6 # N Day / cow)
20 Cold-season Grass Seed, Hay residues
or Pasture
100-130 lbs. N / acre
21 cool-season grass - Reserve
Growth fall
£ 160. N / acre
24 Sudan grass and etc. Hay (performance target) x (40 N / Ton)
25 Sudan grass and etc. Pasture (performance target) x (0.6 # N Day / cow)
26 warm-season grass hay
27 warm-season grass pasture
£ 60. N / acre
6
Table III. nitrogen values for use in recommending N fertilizer for row crops and small grains
Vegetative harvested product *
Crop Yield Yield N necessary *** N Lb. N in Soil OM +
Cultures Code Unit Lbs / A% lb / adjustment unit Yield%
100 Barley bushels / A 3000 0.6 18 2.0 0.96 no
Buckwheat £ 101 / A 2000 2.5 50 5.0 05 yes
£ 102 Cotton / A ----- not
103 Corn, grain bu / A see text 1.6 0.9 yes
Corn silage 104 T / A --- 0.45 9.0 yes
105 CC ** - wheat + soybean bushels / A as wheat ----------------------------------- ------------------- not
106 CC - Wheat Sunflower + bu / A as wheat ------------------------------------- ----------------- not
107 CC - Wheat Sorghum + bu / A as wheat ------------------------------------- ----------------- not
108 CC - Wheat silage sorghum + bu / A as wheat ----------------------------------- ------------------- not
Oats 109 BU / A 4000 0.6 24 2.0 0.64 no
£ 110 Popcorn / A 6000 1.2 72 1.6 0.016 yes
Rice 111 lbs / A 5000 0.6 30 1.3 0.013 yes
112 bushels Rye / A 3000 0.5 15 2.1 1.18 no
Sorghum 113 lbs / A 6000 1.0 60 1.4 .014 yes
Sorghum silage 114 T / A NA NA NA 13.0 .65 yes
Soybean 115 bu / A NA NA NA 0 0 no
Beetroot 116 T / A ---- 4.0 yes
£ 117 Sunflower / A 3000 1.0 30 2.6 .026 yes
£ 118 Tobacco / A - 145 3.6 036 yes
Wheat 119 bushels / A 3000 0.6 18 2.1 1.26 no
** DC = Double cultures
* Vegetative refers to stems, stalks, straw residues or culture. The yield is expected to average conditions.
Necessary *** N = X Yield (% N x 100)
+ See Table I
7
Table IV. Equations to determine the nitrogen requirements of the line and small grains.
Crop Code cultures
100 Barley 18 + (performance target) x (0.96) - (set of organic matter) *
101 Buckwheat 12 + (performance target) x (0.02) - (set of organic matter) *
102 Cotton * 0.1 (performance target - 500) + 50 + CEC
plant population
103 Corn, grain 1000 x (4) + (0.9) x (target return) - (organic matter
Matter Adjustment) *
104 Corn silage (performance target) x (9.0) - (set of organic matter) *
105 See Double crops wheat and soybeans.
106 See Double crop wheat and sunflowers.
107 See Double crops wheat and sorghum.
108 See Double crops wheat and sorghum silage.
109 Oats 24 + (performance target) x (0.64) - (set of organic matter) *
110 Popcorn 72 + (performance target) x (0.016) - (set of organic matter) *
111 Rice 30 + (performance target) x (0.013) - (set of organic matter) *
112 Rye 15 + (performance target) x (1.18) - (set of organic matter) *
113 Sorghum 60 + (performance target) x (0.014) - (set of organic matter) *
13 x 114 Sorghum silage (performance target) - (adjustment of organic matter) *
115 Soy No recommended
116 Sugar beet (4) x (target return) - (Setting the organic matter) *
117 Sunflowers 30 + (performance target) x (0.026) - (set of organic matter) *
Tobacco 118 145 + (performance target) x (0.036) - (set of organic matter) *
119 Wheat 18 + (performance target) x (1.26) - (set of organic matter) *
* See Table I for the control of organic matter.
8
Available phosphorus
Soil analysis
An analysis of soil to determine the available phosphorus is I Bray Bray or low test.
The results are expressed in pounds of P per hectare.
The evaluation system
Crops and crop rotations require different levels of available phosphorus.
In general, even in row crops, it is recognized that the response of phosphorus varies. Soy
are not as sensitive as corn or wheat, for example. However, it is suggested that
levels of soil test phosphorus be built at a sufficient level to not be limited to, general
crop production line, regardless of the specific cultivation. level of soil analysis suggested phosphorus
for row crops and small grains is 45 pounds P per acre. At this level, the potential
response to the supplemental phosphorus fertilizer is low. A maintenance application of
fertilizer is suggested for the analysis of soil between 45 and 70 pounds of available P per acre.
Drilling do well at slightly lower available phosphorus levels, soil analysis suggested
levels of 30 or 40 pounds P / acre. V lists the fertility rates and the corresponding table
levels of soil analysis. TFR for a level test given soil depends on soil analysis desired
level for a given culture. The equation used to determine the fertility rate when the soil test is
lower desired is:
FI = (200/STPd) x CPP - (100/STPd
2) x STPO
2
Where fi = fertility rate
Stpd = desired soil test P level (30/40 or 45 pounds. P A)
CPP = P soil test level observed or actual
The fertility test levels in the higher ground to the desired level is calculated
using the equation:
FI = 100 x STPO
Stpd
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Table V. Bray Notes I test soil, fertility rates, and the corresponding values of soil analysis.
Soil test levels corresponding to FI
Fertility for Bray PI analysis of desired floor =
rating index (FI) 30 40 45
Very Low 0-50 0-9 0-12 0-14
Low 50-75 9-15 12-20 14-22
Average 75-100 15-30 20-40 22-45
Top 100-150 30-45 40-60 45-70
High 150-300 45-90 60-120 70-135
Extremely high 300 + 90 + 120 + 135 +
Information on the level of analysis required for each topsoil is shown in Table VI.
General definitions and interpretations of test grades of soil are given in
Table VII.
Recommendations
Phosphorus soil test interpretation and subsequent fertilizer recommendations are
based on the concept of accumulation and maintenance fertilization described by TR Fisher
Experiment in Missouri Research Bulletin Agricultural Station in 1007 entitled "Some
Considerations for the interpretation of soil tests for phosphorus and potassium "and dated
December 1974.
The suggestion of fertilizer can be defined by its two components, the accumulation and
where the interview:
Lbs. P2O5/acre = Accumulation + P2O5 P2O5 Maintenance
The first involves P2O5 fertilizer requirements to increase soil test
level to the desired level over a number of years.
The equation used to calculate the annual accumulation is:
Accumulation P2O5 = 110 x (stpd
0.5 - Code of Criminal Procedure
0.5) / Year
Where: stpd = desired level of soil analysis kg. M / S (30, 40, or 45)
CPP = level observed or actual soil analysis
Years = suggested number of years to increase soil analysis at the desired level
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The number desired level of soil test Bray and I suggested several years to increase the soil test
levels to the desired level are given in Table VI for each crop. P2O5 fertilizer rates
necessary to increase the levels of soil test Bray I desired level in 4 or 8 years are given in
Table VIII.
Maintenance requirements are determined using the following equation:
Maintenance P2O5 = (performance target) x (P2O5 removal / output unit)
P2O5 phosphorus removal is given for each crop in Table VI. In establishing
fodder, no fertilizer maintenance is proposed. Double crop choices using removal
two cultures in the calculations of maintenance.
As the levels of soil test phosphorus increases above the level desired response
fertilizer P2O5 addition is not likely. Therefore, only maintenance fertilizer or less is
recommended using the following equation:
Lbs. P2O5/acre = (performance target) (P2O5 removal) 1-2 (FI-100)
100
where: fi = fertility rate, as calculated in the previous section on the rating system
When suggested P2O5 rates are less than 20 lb / acre, but greater than zero, 20 pounds.
P2O5/acre is suggested.
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Table VI. Phosphorus removal and test level P-1 soil Bray desired forage
Suggestion
Years of soil phosphorus desired for
Crop Crop Yield Unit code suppression test level Buildup
lbs P2O5 / kg P / A
transfer unit
1 alfalfa, alfalfa - establishment of grass - 45 4
2 trefoil - grass establishment - 30 4
3 clover - establishment of grass - 40 4
4 Cool season grass establishment - 40 4
Lespedeza 5 - Implementation of the grass - 30 4
6 seeding legumes into existing grass - 40 4
7 warm season grass establishment - 30 4
8 quintals of food Wildlife Land 0.0093 45 8
Bermuda grass is 9 - 40 4
10 Alfalfa, alfalfa - hay ton / a 10.0 40 8
11 Alfalfa - grass pasture cd / a 0.05 40 8
12 Trefoil - grass pasture cd / a 0.04 August 30
13 Bluegrass pasture cd / a 0.05 40 8
Bermudagrass 14 ton hay / a 9.0 40 8
15 Bermudagrass pasture cd / a 0.05 40 8
16 Clover - hay ton / a 8.2 40 8
17 clover - grass pasture cd / a 0.03 40 8
Season 18 fresh hay ton / a 9.0 40 8
19 cool season grass pasture cd / a 0.05 40 8
20 cool season grass seed - 40 8
21 cool season grass - Growth stocks fall - 40 8
Lespedeza 22 - ton hay / a 8,8 30 August
23 Lespedeza - grass pasture cd / a 0.04 30 8
24 Sudan grass hay ton / a 6.9 40 8
25 Sudan grass pasture cd / a 0.03 40 8
26 warm season hay ton / a 2.0 August 30
27 warm-season grass pasture cd / a 0.01 August 30
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Table VI (continued). Phosphorus removal and test level P-1 soil Bray desired row crops
Suggestion
Years of soil phosphorus desired for
Crop Crop Yield Unit code suppression test Accumulation level *
lbs P2O5 / kg P / A
transfer unit
Barley 100 bu / A 0.38 45 8
£ 101 Buckwheat / A 8 45 0007
£ 102 Cotton / A 8 45 0038
103 Maize (grain) bushels / A 0.45 45 8
104 corn (silage) ton / A 3.6 45 8
105 Double crops: wheat - Soybean ** bu / A - 45 8
106 Double crops: wheat - Sunflowers ** bu / A - 45 8
107 Double crops: wheat - sorghum ** bu / A - 45 8
108 Double crops: wheat - sorghum silage ** bu / A _ 45 8
Oats 109 BU / A 0.26 45 8
£ 110 Popcorn / A 8 45 0008
£ 111 Rice / A 0.0065 August 10
Rye 112 bu / A 0.34 45 8
113 Sorghum (grain) lbs / A 0.0093 45 8
114 sorghum (forage) ton / A 4.6 45 8
Soybean 115 bu / A 0.84 45 8
Beetroot 116 tons / A 1.33 45 8
Sunflowers 117 lb / A 0.0083 45 8
Tobacco 118 bu / A 8 45 0004
Wheat 119 bu / A 0.60 45 8
201 South peas - 45 8
* Shorter accumulation periods can be selected by the user and may be particularly suitable for variable rate
fertilizer applications.
P ** Double crop maintenance is calculated using the performance goal came for wheat and yields suspected
for double cropping appended.
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Table VII. The definitions of interpretation notes for phosphorus and potassium soil tests
Note Fertility Index Definition
Very low <50 A large accumulation of available
nutrients required. Inputs
and banding will improve
the effectiveness of the fertilizer used.
50-75 Low Moderate accumulation is required.
Banding fertilizer can be
beneficial.
Average 75-100 slight accumulation is desired, which
may be accomplished with
slightly higher applications
maintenance requirements.
Top 100-150 no accumulation is required. Available
nutrient levels should be maintained
with maintenance treatments.
150-300 The high level of nutrients is available
currently adequate, no annual
maintenance treatments are needed.
Monitor the level of available
nutrients from the soil test every three
to four years.
Extremely high> 300 The level of nutrients available is sufficient
up to potentially
cause an imbalance of nutrients. Use factory
analysis to monitor the situation
14
Table VIII. Annual fertilizer P2O5 rate level needed to build soil test Bray PI to the desired level in 4 or 8
years.
----------------------- Desire Bray PI Soil Test Level --------------------- -------
(Lbs P / A)
Observed Bray PI ------ 30 ---------- - 40 ---------- - 45 ------
Soil test level four years. 8 years. 4 years. 8 years. 4 years. 8 years.
(Lbs P / A) ------------------------------------ (lb P2O5 / A) - --------------------------------------
2 112 56 135 68 146 73
4 96 48 119 60 129 65
6 83 42 106 53 117 58
8 73 36 96 48 107 53
10 64 32 87 43 98 49
12 55 28 79 39 89 45
14 48 24 71 36 82 41
16 41 20 64 32 74 37
18 34 17 57 29 68 34
20 28 14 51 25 61 31
22 22 11 45 22 55 28
24 16 8 39 20 50 25
26 10 5 34 17 44 22
28 5 3 28 14 39 19
30 0 0 23 12 34 17
32 0 0 18 9 29 14
34 0 0 14 7 24 12
36 0 0 9 4 19 10
38 0 0 4 2 15 7
40 0 0 0 0 11 5
42 0 0 0 0 6 3
44 0 0 0 0 2 1
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Exchangeable potassium
Soil analysis
Soil analysis used to determine the level of exchangeable potassium is extracted with the
neutral, normal ammonium acetate. The results are recorded in pounds of K per acre. Cation
exchange capacity (CEC) is also used in making interpretations and recommendations. The CEC
is calculated by adding the milliequivalents of calcium, magnesium, potassium, and hydrogen.
CEF is expressed as milliequivalents (MEQ) to 100 grams of soil.
The evaluation system
Soil test potassium levels vary desired crop to be grown and the soil CEC. Drilling
except pure alfalfa stands, having a desired level of potassium 160 pounds. K per acre plus 5 times
CEC. row crops want a level of 220 pounds. K per acre over 5 times CEC.
As soil CEC increases, levels of soil test potassium desired increase at a rate of 5 pounds. K
1 acre with each meq/100g the CEC. For example, corn on soil with a CEC
meq/100g have a desired level of potassium 220 + 5 (10) = 270 lbs. K / acre.
Potassium assessments are calculated using the following equation when the levels of soil analysis
is less than desired:
FI = (200/STKd) x STKo - (100/STKd
2) x STKo
2
Where: fi = fertility rate
Stkd = K level analysis of the desired floor (160 + 5 (CEC) or 220 + 5 (CEC) K lb / ac)
CEC = cation exchange capacity (meq/100 g)
K = level STKo analysis observed or actual floor
When soil test potassium are more than desired, the fertility rate is calculated using the
equation:
FI = 100 x STKo
Stkd
Assessments, fertility rates, and information on the interpretation of the desired soil test levels are given
in Table XI.
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Recommendations
Potassium fertilization rates suggested are based on a concept very similar to phosphorus
interpretations. The components of the accumulation and maintenance fertilization are used again.
The component of the accumulation of potassium is designed to gradually increase the soil test K
level to the desired value during a period of about 8 years.
The equation used to calculate the annual accumulation is:
Accumulation K2O = 75.5 (stkd
0.5 - STKo
0.5)
Years
Where: stkd = desired level of soil analysis (160 + 5 (CEC) or 220 + 5 (CEC) K lbs / acre).
STKo = test level of observed or actual soil (K lb / acre)
CEC = cation exchange capacity (meq/100 g)
Years = suggested number of years to increase soil analysis at the desired level
The number desired level of soil test K and suggested years to build soil test levels to
desired level are given in Table X for each culture. K2O fertilizer rates needed to construct K
soil test levels over 8 years to a desired level of 160 + 5 (CEC) and 220 + 5 (CEC) are given in
Tables XI and XII, respectively.
fertilizer needs maintenance are determined using the following equation:
Maintenance K2O = (performance target) x (K2O removal / output unit)
Potassium (K2O) removal per unit of output is given for each crop in Table X. In establishing
fodder, no fertilizer maintenance is proposed. Double crop choices using removal of both
cultures in the calculations of maintenance.
The fertilizer rates suggested to use each year can then be determined by the equation:
Suggested K2O/acre = Accumulation + K2O K2O Maintenance
when the test floor for potassium is less than desired.
If the test soil potassium is greater than the target level, using culture soil available
potassium is recommended to pull down the level of soil test K available. Maintenance or partial
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fertilizer maintenance doses are available when soil tests are highly rated. The calculations for
proposed during soil tests K2O rates are high are made using the equation:
Suggested K2O/acre = (performance target) (K2O removal) 1-2 (FI-100)
100
where: = IF, the total fertility rate, as calculated in the previous section on the coast
system.
When rates of potassium fertilizers are calculated less than 20 pounds. K2O/acre, but greater than
zero, 20 pounds. K2O/acre is suggested.
When potassium soil test is in the very high or very high range, no potassium
fertilizer is suggested.
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Table IX. Interpretations of soil testing and notes potassium.
Desired level of exchangeable potassium (K lb / A)
Fertility 160 + 5 (CEC) 220 + 5 (CEC)
Index --------------------------- --------------------- CEC CEC --------------------------------- ---------------- ---------
Note (FI) 6 12 18 6 12 18
(Lbs K / A soil test)
Very Low 0-50 0-56 0-65 0-74 0-74 0-83 0-91
Low 50-75 56-95 65-110 74-125 74-125 83-140 95-155
Average 75-100 95-190 110-220 125-250 125-250 140-280 155-310
Top 100-150 190-285 220-330 250-375 250-375 280-420 310-465
High 150-300 285-570 330-660 375-750 375-750 420-840 465-930
Extremely high 300 + 570 + 660 + 750 + 750 + 840 + 930 +
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Table X. removal of potassium and the level of analysis of soil exchangeable desired forage
Suggestion
Desired years for soil potassium
Crop Crop Yield code suppression unit test level Buildup
K2O lbs / kg K / a
transfer unit
1 alfalfa, alfalfa - grass establishment - 220 + (5 x CEC) 8
2 trefoil - grass establishment - 160 + (5 x CEC) 8
3 clover - grass establishment - 160 + (5 x CEC) 8
4 Cool season grass establishment - 160 + (5 x CEC) 8
5 Lespedeza - establishment of grass - 160 + (5 x CEC) 8
6 seeding legumes into existing grass - 160 + (5 x CEC) 8
7 warm season grass establishment - 160 + (5 x CEC) 8
Wildlife food plot 8 lb / a 0.006 220 + (5 x CEC) 8
9 creation of Bermudagrass - 160 + (5 x CEC) 8
10 Alfalfa, alfalfa - hay ton / a 45,220 + (5 x CEC) 8
11 Alfalfa - grass cd / a 0.23 160 + (5 x CEC) grazing 8
12 Trefoil - grass pasture cd / a 0.10 160 + (5 x CEC) 8
13 Bluegrass pasture cd / a 0.15 160 + (5 x CEC) 8
Bermudagrass hay 14 ton / a 34,160 + (5 x CEC) 8
15 Bermudagrass pasture cd / a 0.17 160 + (5 x CEC) 8
16 Clover - hay ton / a 38,160 + (5 x CEC) 8
17 clover - grass pasture cd / a 0.19 160 + (5 x CEC) 8
Season 18 fresh hay ton / a 34,160 + (5 x CEC) 8
19 cool season grass pasture cd / a 0.17 160 + (5 x CEC) 8
20 cool season grass seed - 160 + (5 x CEC) 8
21 cool season grass - Growth stocks fall - 160 + (5 x CEC) 8
22 Lespedeza - hay tons / 20,160 + (5 x CEC) 8
23 Lespedeza - grass pasture cd / a 0.10 160 + (5 x CEC) 8
24 Sudan grass hay ton / a 19,160 + (5 x CEC) 8
25 Sudan grass pasture cd / a 0.09 160 + (5 x CEC) 8
26 warm season hay ton / a 14.6 160 + (5 x CEC) 8
27 warm-season grass pasture cd / a 0.07 160 + (5 x CEC) 8
20
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Table X (continued). Removal of potassium and the level of analysis of soil exchangeable desired row crops
Suggestion
Desired years for soil potassium
Crop Crop Yield code suppression unit test level Accumulation *
K2O lbs / kg K / a
transfer unit
Barley 100 bu / a 0.24 220 + (5 x CEC) 8
£ 101 Buckwheat / a 0.003 220 + (5 x CEC) 8
£ 102 Cotton / a 0.035 220 + (5 x CEC) 8
103 Maize (grain) bu / a 0.30 220 + (5 x CEC) 8
104 corn (silage) ton / a 9.0 220 + (5 x CEC) 8
105 Double crops: wheat - Soybean ** bu / a - 220 + (5 x CEC) 8
106 Double crops: wheat - Sunflowers ** bu / a - 220 + (5 x CEC) 8
107 Double crops: wheat - sorghum ** bu / a - 220 + (5 x CEC) 8
108 Double crops: wheat - sorghum silage ** bu / a - 220 + (5 x CEC) 8
Oats 109 bu / a 0.19 220 + (5 x CEC) 8
£ 110 Popcorn / a 0.005 220 + (5 x CEC) 8
£ 111 Rice / a 0.004 125 + (5 x CEC) 8
Rye 112 bu / a 0.34 220 + (5 x CEC) 8
113 Sorghum (grain) lbs / a 0.006 220 + (5 x CEC) 8
114 sorghum (forage) ton / a 10.0 220 + (5 x CEC) 8
Soy 115 bu / a 1.44 220 + (5 x CEC) 8
Beetroot 116 tons / a 3.33 220 + (5 x CEC) 8
117 lbs / a Sunflowers 0.007 220 + (5 x CEC) 8
£ 118 Tobacco / a 0.04 220 + (5 x CEC) 8
Wheat 119 bu / a 0.30 220 + (5 x CEC) 8
201 South peas - 160 + (5 x CEC) 8
* Shorter accumulation periods can be selected by the user and may be particularly appropriate for the variable rate fertilizer applications.
Double crop maintenance ** K is calculated using the performance goal came for wheat and suspected double crop yields given
attached.
21
Table XI. Annual rate K2O fertilizer needed to build soil analysis exchangeable potassium
levels of 160 + 5 x (CEC) in 8 years.
CEC (meq/100 g)
Soil test level 4 8 12 16 20
(Lb K / y) -------------------------------------- (lb K2O / A) --------------------------------------
40 67 74 80 86 92
60 54 60 67 73 79
80 42 49 56 62 68
100 32 39 46 52 58
120 23 30 36 43 49
140 15 22 28 34 40
160 7 14 21 27 33
180 0 7 13 20 26
200 0 0 7 13 19
220 0 0 0 6 12
240 0 0 0 0 6
260 0 0 0 0 0
Target level 180 200 220 240 260
Table XII. Annual rate K2O fertilizer needed to build soil analysis exchangeable potassium
levels to 220 + 5 x (CEC) in 8 years.
CEC (meq/100 g)
Soil test level 4 8 12 16 20
(Lbs K / A) -------------------------------------- (lb K2O / A) --------------------------------------
40 86 92 98 104 109
60 73 79 85 90 96
80 62 68 74 79 84
100 52 58 64 69 74
120 43 49 55 60 65
140 34 40 46 52 57
160 27 33 39 44 49
180 20 26 31 37 42
200 13 19 24 30 35
220 6 12 18 23 29
240 0 6 12 17 23
260 0 0 6 11 17
280 0 0 0 June 11
300 0 0 0 0 5
320 0 0 0 0 0
Target level 240 260 280 300 320
22
soil acidity and RECOMMENDATIONS OF LIMESTONE
Soil analysis
The acidity of the soil is measured based on the salt (pH) from the floor. Measurements of pH
the active acidity in the soil, and whether the applications of limestone is required. Of
determine the amount of acidity or reserve requirement of limestone to neutralize soil acidity,
the milliequivalents of acidity is measured by the neutralizable Woodruff buffer.
The evaluation system
Overall system for measuring pH for crops is shown below. The prices
was divided into two groups. Alfalfa is a sensitive crop to soil acidity and, therefore, has
a separate classification.
All the others
Note alfalfa
------------------- PH Range -----------------
Very low <5.0 <4.5
Low 5.0 to 5.8 4.5 to 5.3
Average 5.8-6.5 5.3 to 6.0
High 6.5-7.5 6.0-7.5
High> 7.5> 7.5
Soils with a very low or low rating pH have a real need for limestone. These soils
may limit the yield potential due to severe soil acidity. In the medium pH indicates the need for
limestone in the near future, but the acidity of the soil is probably not cause yield losses at the
the test. The soils have a high nominal pH optimum for the growth of crops and limestone soil is not necessary
the next two or three years.
23
23
Limestone Recommendations
recommendations of limestone for all cultures are based on a single application of
suggested amount of material effectively neutralizing (NHS). The amount proposed should provide
the soil pH within the optimal range for the growth of crops. When several options are harvesting
selected, the rate of lime is proposed based on the most demanding pH harvest.
Crops and optimum pH ranges for soil areas in Missouri are given in Table
XIII. All soils used for row crops should be limed to a pH of 6.1 to 6.5. Soil forage
cultures vary in PHS optimal levels. Alfalfa and clover need a slightly higher pH optimum
growth. Forage crops grown in the Cherokee Prairie Ozarks and Ozark border areas (soil
Regions 5, 6, 7 and 8) generally have a higher optimum pH range due to high levels of basement
acidity.
To determine the recommended dose of effective neutralizing material (ENM), locate the
desired pH vary depending on the crop rotation plan and the region of the ground from which the sample was
obtained (Table XIII). Then refer to the appropriate table (Tables XIV-XVI) to determine ENM
requirements based on the level of acidity and pH neutralizable.
To determine the needs of limestone tons / acre, divide the requirement by the NHS NHS
index for the material to be used for liming. All liming materials are sold with a warranty NHS
value as provided by Liming Missouri law.
24
Table XIII. Soil pH to the desired crop will in Missouri
Soil areas
5, 6, 7, 8, 1, 2, 3, 4, 9, 10, 11, 12
Prairie Cherokee Ozarks,
Crop Code cultures and borders Ozark All other soils
1 establishing alfalfa 6.6-7.0 6.1-6.5
2 trefoil - is. 6.1-6.5 5.6-6.0 Grass
3 at Clover 6.1-6.5 5.6-6.0
4 cool season grass. 5.6-6.0 5.6-6.0
5 Lespedeza - is. 6.1-6.5 5.6-6.0 Grass
6 seeding legumes 6.1-6.5 5.6-6.0
7 warm season grass. 5.6-6.0 5.6-6.0
10, 11 Alfalfa 6.6-7.0 6.1-6.5
12 Trefoil - clover pasture 6.1-6.5 5.6-6.0
13 Bluegrass pasture 5.6-6.0 5.6-6.0
14, 15 Bermudagrass 5.6-6.0 5.6-6.0
16, 17 Clover 6.1-6.5 5.6-6.0
18,19.20,21 cool season grasses 5.6-6.0 5.6-6.0
22, 23 Lespedeza 6.1-6.5 5.6-6.0
24, 25 5.6-6.0 5.6-6.0 Sudan grass
26, 27 warm-season grasses 5.6-6.0 5.6-6.0
100-119 All row crops 6.1-6.5 6.1-6.5
25
Table XIV. NHS requirements (effective neutralizing material) to increase soil pH
to 5, 6 to 6.0 range based on soil pH and acidity neutralizable (NA).
ENM = (400) NA - NA
19.109 to 4.802 (pH) + 0.297 (PHS) 2
PH acidity neutralizable ----------------------------- ------------------ ------------
meq/100g 4.0 4.4 4.8 5.2 5.5
--------------------- Lbs. ENM/A-------------------
1.0 314 298 262 216 162
2.0 628 586 524 431 324
3.0 942 878 787 647 487
4.0 1256 1171 1049 863 649
5.0 1570 1464 1311 1078 811
6.0 1884 1757 1573 1294 973
7.0 2198 2049 1835 1509 1136
8.0 2512 2342 2097 1725 1298
9.0 2826 2635 2360 1941 1460
10.0 3140 2928 2622 2156 1622
Table XV. NHS requirements (effective neutralizing material) to increase soil pH to
6.1 to 6.5 range based on soil pH and acidity neutralizable (NA).
ENM = (400) NA - NA
41.425 to 10.307 (pH) + 0.629 (PHS) 2
PH acidity neutralizable ------------------------------ ----------------- -------------
meq/100g 4.0 4.4 4.8 5.2 5.5 6.0
--------------------- Lbs. ENM/A-------------------
1.0 361 352 338 317 283 220
2.0 722 703 676 635 567 441
3.0 1083 1055 1014 952 850 661
4.0 1444 1406 1352 1269 1134 882
5.0 1805 1758 1690 1587 1417 1102
6.0 2166 2109 2028 1904 1701 1322
7.0 2527 2461 2365 2221 1984 1543
8.0 2888 2812 2703 2538 2267 1763
9.0 3249 3164 3041 2856 2551 1983
10.0 3610 3515 3379 3173 2834 2204
26
Table XVI. Requirements (ENM effective neutralizing material) to improve the soil
pH in the range of 6.6 to 7.0 depending on the acidity of the soil neutralizable (NA).
ENM = (400) (NA)
ENM neutralizable acidity
meq/100g (kg / year)
1.0 400
2.0 800
3.0 1200
4.0 1600
5.0 2000
6.0 2400
7.0 2800
8.0 3200
9.0 3600
4000 10.0
27
MAGNESIUM EXCHANGE
Soil analysis
Exchangeable magnesium is extracted from the ground to the neutral aid, normal ammonium
acetate.
The evaluation system
The note of a soil test magnesium is based on the saturation level of magnesium of
cationic exchange of the soil. High levels of saturation of magnesium are available on forage to help
prevent grass tetany. Two general groups are used for evaluation of magnesium.
All the others
Note grasses Forage Crops
% Mg saturation of the CEC
Very low <5 <2
Low 5 - 2 was October 5
Medium 10 - 15 5-10
Top 15-35 of 10 to 32.5
Very high from 35 to 55 32.5 to 55
Extremely high> 55> 55
Recommendations for magnesium
Corrective magnesium is suggested that the effective magnesium (EM) when magnesium
saturation of the cation exchanger of a total ground is less than 5%. Soils containing between 5.1 and
9.9 percent saturation of magnesium are considered less optimal magnesium and
resulting triple asterisk (***) appears in the recommendations. This is to indicate that if
dolomitic limestone is readily available, it can be used, but the crop response to magnesium is not
probable. Table XVII shows the levels of magnesium suggested to be used as corrective treatment.
Poor soil magnesium should be retested after four years to determine the levels of magnesium
Following treatment.
28
28
To determine the amount of a liming material magnesium needed to correct low soil
exchangeable magnesium, divide the effective magnesium (EM) by the effective magnesium
index for the material to be used for liming.
Table XVII. Effective needs magnesium to correct magnesium soil.
------------ Cation Exchange Capacity (meq/100 g) --------------
Exchangeable magnesium 6 10 14 18 22 26 30
(Lbs Mg / A) -------------- effective magnesium (EM) lbs/A--------------
40 60 100 140 180 220 260 300
80 50 80 110 135 175 210 240
120 35 60 85 110 130 155 180
160 25 40 55 70 90 105 120
200 20 20 30 35 45 50 60
240 0 0 0 0 0 0 0
29
Exchangeable calcium
Soil analysis
Exchangeable calcium neutral medium is extracted with a normal ammonium acetate.
Notes
Notes for calcium is based on the pH level of the soil and not on the analysis of soil calcium. If the
PHS is very low or low, calcium is average nominal. Calcium is considered high if the pH is average or
later.
Recommendations
Calcium is rarely, if ever, deficient in the soil on the ground. No recommendation for calcium are
made on the basis of soil analysis exchangeable calcium. Exchangeable calcium is mainly used for
using the determination of cation exchange capacity of about ground.
30
SULPHUR
Soil analysis
There are two tests available in the soil to be used to interpret the needs of sulfur: 1) extracting
sulphate sulfur using 500 ppm P as Ca (H2PO4) 2 • 2 H2O in 2 N acetic acid as an extracting agent and 2)
cation exchange capacity determined by summing the milliequivalents of exchangeable calcium
magnesium, potassium and hydrogen.
The evaluation system
The scoring system used to sulfur involves both soil sulphate sulfur and cation exchange
capacity. Research by Dr. RG Hanson said the soil with either a sulfate sulfur
greater than 7.5 ppm of SO4-S or an exchange capacity of greater than 6.5 meq/100 g cation content are
not likely to respond to application of sulfur fertilizer. A simple table can be used to display notes
for the status of sulfur Missouri soil (Table XVIII).
Table XVIII. Notes sulfur status of soils.
cation exchange
the capacity of the soil (meq/100g)
Sulphate sulfur 0-6.5 6.5 +
(Ppm SO4-S) ------------- sulfur status
0-7.5 Low Medium
7.5 + Medium High
The proposed treatment
For row crops, small grains and alfalfa, apply 10 to 20 pounds of S per acre per year,
Note when soil test for S is low. Most other forages do not require O even when the soil sulfur
status is low.
31
31
The sulfur is not available on soils appropriate tests based on either the cation exchange capacity
or analysis of sulfate sulfur sol.
Table XIX. Suggested application rate of sulfur when the state of soil sulfur is low and depends
soil analysis sulphate sulfur and cation exchange capacity.
Crop Code cultures sulfur rate
(Lb S / A)
2-7, 11-27 All except forage alfalfa hay 0
1, 10, 11, 101-110 alfalfa and all row crops and small grains 15
32
Micronutrients (zinc, iron, manganese, copper)
Soil analysis
The analysis of the soil used for the analysis of micronutrients is called the DTPA extraction method.
The results are expressed in parts per million (ppm) of each trace element.
The evaluation system
The scoring system used for soil analysis is based on information from Soltanpour, PN and
A.P. Schwab. 1977. Communications in soil science and plant analysis. 8 (3). 195-207.
Table XX shows relative valuations of four levels of micronutrients.
Zinc deficiencies have been noted in Missouri on soils with sandy texture, low organic
issue and the graduated or eroded areas where basements are exposed.
Iron, manganese and copper has not been shown to be deficient in any widespread
case in Missouri. Only in isolated cases would lack one of these micronutrients
predict.
Table XX Notes for levels of analysis of soil DTPA extractable micronutrients.
Soil Test Rating Iron Zinc Copper Manganese
----------------------------------- Ppm -------------- ---------------------
Low 0-0.5 0-2.0 0-1.0 0-0.2
Average 0.5-1.0 2.1-4.5 -
Top 1.0 + 4.6 + 1.0 + 0.2 +
33
The treatments proposed
Zinc
Assessments and recommendations of zinc are used in corn and sorghum. These
recommendations for a single application to corrective soil should last three to five
years. Some fertilizers zinc are very insoluble and poor sources of zinc. Zinc sulfate is
recommended. If chelates are used, reduce demand by a third half and apply each year.
Monitor levels with soil testing and frequent analyzes of plants.
DTPA suggested
Soil Application Test
Level Rating Rating
ppm Zn lbs. Zn / acre
0 - 0.5 Low 10
0.5 to 1.0 Medium 5
1.0 High 0
Iron
Foliar sprays of 0.5 to 3 pounds per acre of actual iron have been shown to be more
effective. These can be offered when soils test low in iron and visual impairment
symptoms are observed. This is more likely to occur on high pH soils in the bottom of the Missouri River.
Soil applications of iron have not been very effective in correcting iron deficiency. In the long term
correction can be better achieved by the application of manure.
Copper
Soil testing low copper should be monitored for symptoms of deficiency. Foliar
application at the rates suggested by the manufacturer to the acre should be sufficient to correct
deficiency symptoms that may occur. ground applications February-August pounds of copper per hectare
can be used, but it will be of questionable value. Half this rate would be proposed if land use
applied. chelate
Manganese
Low soil test manganese should be monitored for symptoms of deficiency. Foliar
applications of 1-2 pounds per acre of actual manganese should correct deficiencies that may
produce.
34
Cation exchange capacity
Soil cation exchange capacity (CEC) is determined by summing the milliequivalents of
calcium, magnesium, potassium, and hydrogen based on the tests measuring soil nutrients.
This is only an estimate of the CEC and should not be confused with other more specific
measuring methods.
The evaluation system
Soil CEC is used as a method for estimating soil texture.
Cation exchange capacity of the soil texture
meq/100g
<5.0 Sand
5.1 to 10.0 sandy loam
10.1 to 18.0 loam
18.1 to 24.0 clay
> 24.0 Clay
The method used to calculate the CEC:
meq/100g = lbs. AC / A + lbs. Mg / A + lbs. K / A + meq of acidity neutralizable
400240780
cation saturation may also be determined from these calculations. Convert lb / acre
meq/100g cation (as above), then divide by the soil CEC. Example:
lbs. AC / A = 2400
Ca/100g meq = 2400 = 6
400
CEC = 10.0 meq/100
Therefore% calcium saturation = 60% = 6
10
35
ANNEX
Table A. The following table lists the objectives assumed yield for the second crop in double
Culture system.
Target cultures Code crop yield for the second harvest
105 wheat - soybean 30 bu / A (40 if irrigated)
Wheat 106 - £ 1000 Sunflower / a
107 wheat - sorghum £ 5000 / a
108 Wheat - sorghum silage 10 tons / a
