pss 161 fundamentals of soil...

PSS 161 Fundamentals of Soil ScienceRecitation Problem Sets 2000

Monday 8:00-8:50 a.m.L108 Lafayette Hall

Wendy Sue Harper, Ph.D.Plant and Soil Science

The University of Vermont

Date Scheduled Activities in Class

Complete all the problems and come into class with your questions prepared each week. Completethe Vocabulary, Math & Chemistry Review if you need to refresh yourself, as we will not reviewthis in class.

8/28 Your Questions & Physical Properties of Soil Problem Set

9/4 No class Labor Day!!

9/11 Your Questions & Soil Water Problem Set

9/18 Quiz 1

9/25 Prep for first course exam

10/2 Your Questions & Colloids Problem Set More on CEC, Acidityand Liming

10/9 Your Questions & Acidity and Liming ProblemSet

10/16 Prep for second course exam

10/23 Quiz 2

10/30 Your Questions & Soil Fertility Problem Set

11/6 Your Questions & Soil Test Recommendations Problem Set

11/13 Prep for third course exam

11/20 Your Questions & Soil Pollution Prevention Problem Set

11/27 Quiz 3

12/4 Prep for final: Review Problem Solving Exercise 1 & Exercise 2

PSS 161 Fundamentals of Soil Science

http://pss.uvm.edu/pss161/problems.html [14/07/2001 09:20:01 a.m.]

Fundamentals of Soil Science RecitationProblem Set Prep: Vocabulary, Math and Chemistry Review

Please review the concepts in this problem set to refresh yourself.

1. Mathematical Definitions and Concepts Reviewed

Exponential 10 = 101 1/10 = 0.1 = 10-1

100 = 102 1/100 = 0.01 = 10-2

1,000 = 103 1/1000 = 0.001 = 10-3

Note: when multiplying numbers with exponents you add the exponents, and when dividing you subtract them:

1 x 103 X 1 x 102 = 1 X 105 (1000 X 100 = 100,000) 1 x 103 / 1 x 102 = 1 X 101 (1000/100 = 10)

Logarithms log 102 = 2 log 10-2 = -2 log 103 = 3 log 10-3 = -3 log 1/105 = -log 105 = -5 log 1/10-5 = -log 10-5 = 5 -log 102 = -(2) = -2 -log 10-2 = -(-2) = 2

Working with Fractions

Multiplication Division 1 x 2 = 1 x 2 = 2 = 1

2 3 2 3 6 31/2=1 x 3 = 32/3 2 2 4

Using Proportions

How much Sheep Manure (SM) is needed to supply 0.7# N/1000 sq.ft. of garden if 100#'s of Sheep Manure contain 1# N?

100# SM = X# SM to apply

1# N 0.7# N for 1000 sq.ft.

Do the math: cross multiply.

0.7# N x 100# SM = X# Sheep Manure to apply

1# N

X# = 70# SM (Sheep Manure)

Expressions used in weights and concentrations

term abbreviation meaning use

Kilo k 1000 = 103 1 kg = 1000 g

milli m 0.001 = 10-3 1 mg = 0.001 g

micro m 0.000001 = 10-6 1 µg = 0.000001 g

Liter l 1000 cc or ml 1000 ml = 1 l

part per million ppm 1g/106g 1mg/103g = 1mg/liter

1 µg/g =1 µg/ml

Handy Soil Conversions (weight to volume)

The 6" plow layer of one acre (A) of soil weight approximately 2 x 106 lbs. Therefore, if soil contains 150 ppm K there would be 300pp2m or 300 lbs/Acre 6"

In metric:a 15cm plow layer of one hectare (ha) of soil weighs 2,242,000 kg/ha-f.s.

2. Chemical Concepts Reviewed

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Atoms consist of a central core composed of protons (+1 charge) and neutrons (no charge) surrounded by electrons (-1 charge) and areelectrically neutral due to a balance of + and - charges: examples Al0, and Cl0

Ions are atoms or molecules (groups of atoms) that because of losing (or gaining) electrons they have a positive (or negative) charge.

Anions (negative charge): Cl-, SO4=, NO3

-, PO4=

Cations (positive charge): K+, Ca+2, Mg+2, Fe+2 or +3

NOTE: Certain elements will have more than one oxidation state

Fe: +2 Mo: +4, +5, +6 Mn: +2, +4 Cu: +1, +2 C: +2, +4 N: +3, +5, -3 (N-3H4

+1)+, (N+3O2-2)-1, (N+5O3

-2)-1

Bonding

Ionic: Electron(s) is more concentrated around one atom than another. Usually occurs if the atoms are widely separated on theperiodic table, and therefore are very different in electronegativity

K.° + :Cl°: > K+ :Cl-:

Covalent: If the two atoms are very close on the periodic table they will tend to share electrons. This is what happens when carbonbonds to itself

C + C > C:C

Hydrogen Bonding: Compounds with O-H or N-H bonds show evidence of association. The O and N atoms tend to attract theelectrons they share with hydrogen - thus the hydrogen atom assumes character of a proton and will thus share electrons withneighboring O or N atoms.

Atomic Weight is the weight of an atom relative to arbitrary value of 16 for oxygen. It is approximately equal to the number ofprotons + neutrons in the atom. When the weight is expressed in grams it represents the weight of 6.02 x 1023 atoms (Avogadro'snumber).

Mole is the weight, in grams, of 6.02 x 1023 molecules. For example, one mole of H2O weighs 18 grams, and one mole of NH4NO3weighs 80 grams (14 + 4(1) + 14 + 3(16)).

Equivalency is the amount of an element which will combine with or replace 1.008g of hydrogen (one mole), which is called its gramequivalent weight. This is calculated by the following formula:

Eq. wt. = gram atomic weight valence (or oxidation state)

Examples: The atomic weight of calcium (Ca+2) = 40g

eq. wt. Ca = 40g/2 = 20g 1 eq Ca weighs 20g 1 meq Ca = (0.001) x 20g = 20 mg Cl-: eq wt Cl- = 35g/1 = 35g 1 meq = 0.001 x 35g = 10-3 x 35g = 35mg

pH

pH = log [1/H+] = -log[H+]

Where [H+] is the concentration of hydrogen ions expressed in moles/liter.In water [H+] multiplied by the [OH-] equals 10-14.

Thus if [OH-] = 10-8 moles/liter and [H+] [OH-] = 10-14

prob_review


Then: H+ = 10-14 / 10-8 = 10-6 The pH = -log 10-6 = 6

See answers and work to these questions Fill in the missing information in this table:

Element Symbol Molecular Weight Common Forms in Soils (ionic ormolecular)

C

Oxygen

Hydrogen

Nitrogen

Phosphorus

K

Calcium

Mg

Sulfur

Fe

Copper

Zinc

Manganese

Molybdenum

B

Cl

Co

Aluminum

Silicon

3. Some Unit Conversions to Try

1. 10 grams (g) = __________ milligrams (mg)

2. 1.0 meters (m) = _________ centimeters (cm)

3. 4.5 cm = ___________ millimeters (mm)

4. 50 kilograms (kg) = ___________ mg

5. 62 milliliters (ml) = ___________ liters (1)

6. 1.0 hectare = ____________ meters2 (m2)

7. 1.0 acre = ______________ square feet (ft2)

8. 3.0 tons (t) = ____________ lbs

9. 3.0 metric tons (T) = _________ kg

10. 2.2 lbs = ___________ kg

11. 10,000 parts per million (ppm) = ____________ % (parts per hundred)

4. Briefly Define the Following Terms

prob_review


http://pss.uvm.edu/pss161/answers/review.html

abiotic Absorption

adsorption Allelopathy

anion Autotroph

biotic Capillary

cation Colloid

commensalism Detritivores

diffusion Ecosystem

equivalent weight Exudation

heterotroph Ion

Molarity Mole

molecular weight Micron

mutualism Normality

pathogenic Pathogenic

trophic level Valence

prob_review


Fundamentals of Soil Science RecitationProblem Set 1: Physical Properties of Soil

Bring your questions on your problem set calculations to recitation. <Answers>To see work to answers

1. If the specific surface area of sand, silt, and clay is 30, 1500, and 3,000,000 cm2/g what is the total surface areain 100 grams of the following soils? How does the amount surface area effect the behavior of a soil (or why is thisimportant)?

A. Silt loam (20% sand, 60% silt, 20% clay) <60,090,600 cm2>

B. Sandy loam (65% sand, 25% silt, 10% clay) <30,039,450 cm2>

C. Clay (20% sand, 20% silt, and 60% clay) <180,030,600 cm2>

2. In 1992, we compared the following data in PSS 161 lab. Please calculate bulk density and total pore space foreach soil core. The soil core is 5 cm high and 7.5 cm in diameter. Assume the particle density is 2.65 g/cc. What doesthis data tell you about land use and soil types?

Soil/Texture/Site Core Dry Weight (grams) A. Vergennes Clay-Permanent Sod 267 <1.21g/cc, 54.4%> B. Vergennes Clay-Silage Corn 304 <1.38g/cc, 48.1%> C. Windsor Loamy Sand-Permanent Sod 264 <1.20g/cc, 54.9%> D. Windsor Loamy Sand-Silage Corn 315 <1.43g/cc, 46.2%>

Some useful equations to help you.

bulk density = soil dry weight (g)------------------

soil volume (cm3)

Volume of a cylinder = pi*r2*h

% Pore Space = 100 - (Bulk Density/Particle Density X 100)

3. An acre (A) is defined as 43,560 square feet. An acre furrow slice (A-f.s.), the part that is plowed or injected withsewage sludge, is generally 6 inches deep. Calculate the volume of an acre of soil. Also what is the weight of the soilin an acre that has the bulk density of A, B, C and D above?<21,780 ft3><1,645,369.5, 1,876,537, 1,631,771.4, 1,944,527.6 lbs/A f.s.>

4. If you had to choose one of the soils from question one as a site for each of the following uses, which would youchoose and WHY. (1) your soon to be built well-water home on a septic system, 2) a nursery or farming operation, 3)environmental science education center, 4) a temporary above ground nuclear waste disposal site, and 5) a hometownbaseball field (Hey, people make these decisions every day with less soils experience than you have.)

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http://pss.uvm.edu/pss161/problem/prob_set1.html [14/07/2001 09:20:11 a.m.]

Fundamentals of Soil Science RecitationProblem Set 1: Physical Properties of Soil

Bring your questions on your problem set calculations to recitation. <Answers>

1. If the specific surface area of sand, silt, and clay is 30, 1500, and 3,000,000 cm2/g what is the total surface area in100 grams of the following soils? How does the amount surface area effect the behavior of a soil (or why is thisimportant)?

A. Silt loam (20% sand, 60% silt, 20% clay) <60,090,600 cm2>

100 gram sample of silt loam = 20 grams sand (20% sand = 0.20 x 100 g), 60 grams silt, and 20 grams clay. Weknow that sand has a specific surface area of 30 cm2/g; silt 1500 cm2/g; and clay 3,000,000 cm2/g. So the sandcomponent of the silt loam sample has a surface area of (20 gram) x (30 cm2/g)=600 cm2. The silt (60 grams) x(1500 cm2/g) = 90,000 cm2. The clay (20 grams) x (3,000,000 cm2/g)=60,000,000 cm2. The total surface area is 600+ 90,000 + 60,000,000 = 60,900,600 cm2.

B. Sandy loam (65% sand, 25% silt, 10% clay) <30,039,450 cm2>

100 gram sample of sandy loam = 65 grams sand (65% sand = 0.65 x 100 g), 25 grams silt, and 10 grams clay.We know that sand has a specific surface area of 30 cm2/g; silt 1500 cm2/g; and clay 3,000,000 cm2/g. So the sandcomponent of the silt loam sample has a surface area of (65 gram) x (30 cm2/g)=1950 cm2. The silt (25 grams) x(1500 cm2/g) = 37,500 cm2. The clay (10 grams) x (3,000,000 cm2/g)=30,000,000 cm2. The total surface area is1950 + 37,500 + 30,000,000 = 30,039,450 cm2.

C. Clay (20% sand, 20% silt, and 60% clay) <180,030,600 cm2>

100 gram sample of clay = 20 grams sand (20% sand = 0.20 x 100 g), 20 grams silt, and 60 grams clay. We knowthat sand has a specific surface area of 30 cm2/g; silt 1500 cm2/g; and clay 3,000,000 cm2/g. So the sandcomponent of the silt loam sample has a surface area of (20 gram) x (30 cm2/g)=600 cm2. The silt (20 grams) x(1500 cm2/g) = 30,000 cm2. The clay (60 grams) x (3,000,000 cm2/g)=180,000,000 cm2. The total surface area is600 + 30,000 + 180,000,000 = 180,030,600 cm2.

Ratio 180,030,600 (clay):60,090,600 (silt loam):30,039,450 (sandy loam) = 5.993:1.9994:1 = 6:2:1

2. In 1992, we compared the following data in PSS 161 lab. Please calculate bulk density and total pore space for eachsoil core. The soil core is 5 cm high and 7.5 cm in diameter. Assume the particle density is 2.65 g/cc. What does thisdata tell you about land use and soil types?

Soil volume = (pi)(r2)(h) = (pi)(3.75cm{remember: radius is 1/2 diameter})(3.75cm)(5cm) = 220.9 cm3

Soil/Texture/Site Core Dry Weight (grams) A. Vergennes Clay-Permanent Sod 267 Bulk density = 267 g / 220.9 cm3= 1.21 g/cc

% pore space = 100 - (1.21 g/cc / 2.65 g/cc X 100) =54.39%

<1.21g/cc, 54.4%>

B. Vergennes Clay-Silage Corn 304 Bulk density = 304 / 220.9 cm3= 1.38 g/cc


<1.38g/cc, 48.1%>

C. Windsor Loamy Sand-Permanent Sod 264

problem set 1

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Bulk density = 264 / 220.9 cm3= 1.20 g/cc


<1.20g/cc, 54.9%>

D. Windsor Loamy Sand-Silage Corn 315 Bulk density = 315 / 220.9 cm3= 1.43 g/cc


<1.43g/cc, 46.2%>

Some useful equations to help you.

bulk density = Soil dry weight (g)--------------------------

soil volume (cm3)

Volume of a cylinder = pi*r2*h

% Pore Space = 100 - (Bulk Density/Particle Density X 100)

3. An acre (A) is defined as 43,560 square feet. An acre furrow slice (A-f.s.), the part that is plowed or injected withsewage sludge, is generally 6 inches deep. Calculate the volume of an acre of soil. Also what is the weight of the soil inan acre that has the bulk density of A, B, C and D above?

Volume = length x width x depth To find length&width of field take square root of acre (43560 ft2 = 208.7 ft x208.7 ft). Volume then equals 208.7 ft x 208.7 ft x 0.5 ft {6 inches} = 21,780 ft3

Weight of Soil = bulk density x volume of soil

Weight of Soil A = 1.21 g/cc x 21,780 ft3 . Notice that our units are not similar and therefore do not cancel eachother out. We must convert to similar units. There are 453.9 g in 1 pound and 28,320 cm3 in 1 ft3 (1.21 g/cc) x (1lbs./453.6 g) x (28,320 cc/1 ft3) x (21,780 ft3) = 1,645,369.5 lbs/A f.s.

Weight of Soil B = 1.38 g/cc x (1 lbs./453.6 g) x (28,320 cc/1 ft3) x (21,780 ft3) = 1,876,537 lbs/A f.s.

Weight of Soil C = 1.20 g/cc x (1 lbs./453.6 g) x (28,320 cc/1 ft3) x (21,780 ft3) = 1,631,771.4 lbs/A f.s.

Weight of Soil D = 1.43 g/cc x (1 lbs./453.6 g) x (28,320 cc/1 ft3) x (21,780 ft3) = 1,944,527.6 lbs/A f.s.

4. If you had to choose one of the soils from question one as a site for each of the following uses, which would youchoose and WHY. (1) your soon to be built well-water home on a septic system, 2) a nursery or farming operation, 3)environmental science education center, 4) a temporary above ground nuclear waste disposal site, and 5) a hometownbaseball field (Hey, people make these decisions every day with less soils experience than you have.)

problem set 1


Fundamentals of Soil Science RecitationProblem Set 2: Soil Water

Bring your questions on your problem set calculations to recitation. <Answers in brackets>To seethe work and answers

1.a. How much extra energy (kcal) will it take to evaporate the soil water to field capacity (about 25%moisture) in your 10 x 10 ft garden (using an 8 inch depth), which is a silt loam soil with a bulk densityof 1.2 g/cc, if it had 45% moisture to start compared to if it had 35% moisture to start? How much timeof full sun intensity will this take, IF the sun's energy only has to heat up and evaporate the water?(Percent moisture is calculated on a dry soil mass basis.) <122,328 kcal><11.4 hours>

b. If your garden soil from above was soil was bone-dry and you added 2 inches of 40o F water fromyour mountain spring how much energy (kcal) is needed to raise the temperature of the water to 50o F.How much time (minutes) of full intensity sun will this take, IF the sun's energy only has to heat up thewater? <2624 kcal><~15 min>

c. Given that it takes months for soil to warm-up in spring, where does all the energy from the sun go?<Think about it, then jot down your ideas.>

Useful information for the two problems above:

The specific heat (cal required to raise 1 gm of water by 1 degree C) of pure water is 1 cal/g degree (1000cal/kg degree or 4.18 J/g degree). The specific heat of dry soil is 0.2 cal/g degree (0.8 J/g degree).

It takes 540 kcal of energy to evaporate each kg of water from soil (2.257 J/kg water). The sun's radiationintensity at earth is 0.032 cal/cm2 sec (0.134 J/cm2 sec). The density of water is 1 gram/cc.

Percent water for a soil sample is calculated on a dry mass basis as follows: weight of water kg/weight ofdry soil kg x 100 = % moisture (dry mass basis)

2. Determine the Total water potential and direction of flow from the following soil profiles.

Remember: In our simplified system, T = M + G; At equilibrium T1 = T2 = T3 and there is no net flowof water; M is always "-" expect at saturation where M= 0; For G, numbers are "+" above the gravity refpoint (GRP), below the GRP numbers are "-", and at the GRP numbers for G = 0; In soil profiles themost convenience place for the GRP is the water table, but it can be placed anywhere; If you change theposition of the GRP the numbers may change, but the direction of flow remains the same; and Watermoves from high to low (more "+" to more "-") total potential.

Profile 1

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-------------Potentials ------------

Depth G M T

A

B

C

Profile2

-------------Potentials ------------

Depth G M T

A -120

B

C

prob_set2


Profile 3

-------------Potentials ------------

Depth G M T

A -110

B -10

C

Profile 4

-------------Potentials ------------

Depth G M T

prob_set2


A -110

B -40

C

prob_set2


Fundamentals of Soil Science RecitationProblem Set 2: Soil Water

Bring your questions on your problem set calculations to recitation. <Answers in brackets>

1.a. How much extra energy (kcal) will it take to evaporate the soil water to field capacity (about 25%moisture) in your 10 x 10 ft garden (using an 8 inch depth), which is a silt loam soil with a bulk densityof 1.2 g/cc, if it had 45% moisture to start compared to if it had 35% moisture to start? How much timeof full sun intensity will this take, IF the sun's energy only has to heat up and evaporate the water?(Percent moisture is calculated on a dry soil mass basis.) <122,328 kcal> <11.4 hours>

What we know: 10x10ft garden at 8" depth, BD (bulk density)=1.2 g/cc, we want moisture% to be25%.

Let's find the area of the garden in metric. 10ft = ? cm; 10ft x 12"/1ft x 2.54cm/1" = 304.8 cm8"= ? cm; 8" x 2.54cm/1" = 20.32 cm deptharea=length x width x depth= 304.8 x 304.8 x 20.32 = 1,887,789.773 cm3

1.

Now find the weight of the soil.1,887,789.773 cm3 x 1.2g/cm3 x 1kg/1000g = 2265.35 kg soil in 10'x10'x8" garden

2.

How much water do we want to evaporate? 45% to 25% = 45-25= 20% or 35% to 25% =35-25= 10%, so we are going to compare 20% loss to 10% loss or the difference is20-10=10% moisture content on dry mass basis. % moisture = 10%, which means 10 kgwater/100 kg soil. We need to convert this to weight. To find the weight of water = 2265.35kgsoil x 10 kg water/100 kg soil (dry) = 226.53 kg water. To convert this to energy to evaporatethe water = 226.53 kg x 540 kcal/1 kg water = 122,327.86 kcal.

3.

Lastly to convert this to time, we use 0.032 cal/cm2.sec = 1 cm 2.sec/0.032 cal x 100 cal/ 1 kcalx 122,327.86 kcal/1 x 1/92,903.04 cm2 = 41147.69 sec x 1 min/60 sec x 1 hour/60 min = 11.4hours.

4.

b. If your garden soil from above was soil was bone-dry and you added 2 inches of 40o F water fromyour mountain spring how much energy (kcal) is needed to raise the temperature of the water to 50o F.How much time (minutes) of full intensity sun will this take, IF the sun's energy only has to heat up thewater? <2624 kcal> <~15 min>

What we know: 10x10ft garden = 92,903.04 cm2, 2 inches = 5.08 cm, specific heat of water is1°C=1cal/1g water, 40°F=4.44°C, 50°F=10°C, density of water = 1g/1cc

Let's find the volume of water added. 5.08 cm (2 inches) x 92,903.04 cm2 (area of garden)=471,947.44 cm3 volume of water.

1.

We want to raise temp from 40 to 50°F= 4.44°C-10°C=5.56°C and the weight of water is471,947.44 cm3 x 1g/1cc = 471,947.44g

2.

Now let's find the energy to heat the soil. 1cal/1°C.1g water x 471,947.44g x 5.56°C =2,624,027.766 cal x 1 kcal/1000cal = 2624.0 kcal

3.

Time to heat up. 0.032 cal/cm2.sec x 92903.04 cm2 = 2972.90 cal/sec2624027.77 cal x 1 sec/2972.90 cal = 882.65 sec x 1 min/60 sec = 14.71 min

4.

c. Given that it takes months for soil to warm-up in spring, where does all the energy from the sun go?

set_2


<Think about it, then jot down your ideas.>

Useful information for the two problems above:The specific heat (cal required to raise 1 gm of water by 1 degree C) of pure water is 1 cal/g degree (1000cal/kg degree or 4.18 J/g degree). The specific heat of dry soil is 0.2 cal/g degree (0.8 J/g degree).

It takes 540 kcal of energy to evaporate each kg of water from soil (2.257 J/kg water). The sun's radiationintensity at earth is 0.032 cal/cm2 sec (0.134 J/cm2 sec). The density of water is 1 gram/cc.

Percent water for a soil sample is calculated on a dry mass basis as follows: weight of water kg/weight ofdry soil kg x 100 = % moisture (dry mass basis)

2. Determine the Total water potential and direction of flow from the soil profiles on the back.

Remember: In our simplified system, T = M + G; At equilibrium T1 = T2 = T3 and there is no net flowof water; M is always "-" expect at saturation where M= 0; For G, numbers are "+" above the gravity refpoint (GRP), below the GRP numbers are "-", and at the GRP numbers for G = 0; In soil profiles themost convenience place for the GRP is the water table, but it can be placed anywhere; If you change theposition of the GRP the numbers may change, but the direction of flow remains the same; and Watermoves from high to low (more "+" to more "-") total potential.

Profile 1

-------------Potentials ------------

Depth G M T <T>

A <0>

B <0>

C <0>

Profile2

set_2


-------------Potentials ------------

Depth G M T <T>

A -120 <-40>

B <-40>

C <-40>

Profile 3

-------------Potentials ------------

Depth G M T <T>

A -110 <-50>

set_2


B -10 <-10>

C <0>

Profile 4

-------------Potentials ------------

Depth G M T <T>

A -110 <-80>

B -40 <-40>

C <-30>

set_2


Fundamentals of Soil Science RecitationProblem Set 3: Colloids and CEC

Bring your questions on your problem set calculations to recitation. <Answers>To see work1. For each problem figure out the missing information, which is labeled X. Calculate the CEC/acre f.s. andCEC/ha f.s. for each problem. (Note: The table of colliod properties included is very useful here; there are2,000,000 lbs soil/ A f.s. (6 inches) or 2,242,000 kg soil/ ha f.s. (15cm)).

a. CEC = X cmol/kg soil <14 cmol/kg> percent clay = 50%, clay type = kaolinitepercent OM = 5%

<12,727,272.7 cmol/A f.s., 31,388,000 cmol/ha f.s.> <127,008,000 me/A f.s., 313,330,000 me/ha f.s.> b. CEC = 24 me/100g soil percent clay = 30%, clay type = chlorite percent OM = X% <7.5%> <538,080,000 me/ha f.s., 217,728,000 me/A f.s.>

c. CEC = 35 meq/100g soil percent clay = 10%, clay type = X <vermiculite> percent OM = 10% <784,700,000 meq/ha f.s., 317,520,000 me/A f.s.>

2. A 10 gram sample of soil is analyzed for cations. The analysis shows the following:

Ca2+ 0.001 g Mg2+ 0.0005 g K+ 0.00025 g Al3+ 0.0015 g

a. Calculate CEC in meq/100g soil and cmol kg-1. <2.65 cmol/kg=2.65 meq/100g>

b. Calculate base saturation. What is the Ca 2+ saturation? <36.98%, 18.8%>

c. What is the Ca:Mg:K ratio? <7.8: 6.5: 1>

d. Determine the quantity of aluminum for the soil above in the following units:

lbs/acre f.s. ppm tons/acre kg/ha f.s.

prob_set3


<300> <150> <0.15> <336.3kg>

prob_set3


Fundamentals of Soil Science RecitationProblem Set 3: Colloids and CEC

Bring your questions on your problem set calculations to recitation. <Answers in brackets>

1. For each problem figure out the missing information, which is labeled X. Calculate the CEC/acre f.s. andCEC/ha f.s. for each problem. (Note: The table of colliod properties included is very useful here; there are2,000,000 lbs soil/ A f.s. (6 inches) or 2,242,000 kg soil/ ha f.s. (15cm)).

a. CEC = X cmol/kg soil <14 cmol/kg>percent clay = 50%, clay type = kaolinitepercent OM = 5%<12,727,272.7 cmol/A f.s., 31,388,000 cmol/ha f.s.><127,008,000 me/A f.s., 313,880,000 me/ha f.s.>

We know from the colloid hand-out that kaolinite has a CEC of 8 cmol/kg and humus has a CEC of 200cmol/kg. To find the CEC of the soil we need to add the CEC of the components,

for the kaolinite8 cmol x 50 kg clay = 4 cmol/kgkg clay 100kg soil

and

for the humus200 cmol x 5 kg humus = 10 cmol/kgkg humus 100kg soil

therefore, 4 + 10 = 14 cmol/kg CEC for soil.

To find the CEC/acre f.s. we use the CEC of the soil

14 cmol x 1 kg soil x 2,000,000 lbs soil = 12,727,272.73 cmols/A.f.s. kg soil 2.2 lbs soil A.f.s.

To find CEC/ha f.s. we also use

14 cmol x 2,242,000 kg soil = 31,388,000 cmol/ha f.s. kg soil ha f.s.

b. CEC = 24 me/100g soilpercent clay = 30%, clay type = chloritepercent OM = X% <7.5%><538,080,000 me/ha f.s., 217,728,000 me/A f.s.>

We know that 1 me/100g = 1 cmol/1 kg, soil CEC = 24 me/100g, chlorite CEC = 30 me/100g.

To find the % OM we first need to find the CEC of the humus. 30 me/100g clay x 30 g clay/100 g soil = 9me/100 g soil. (Total CEC) 24 - (clay CEC) 9 = 15 meq/100g from Humus. We know from the colloidhand-out that humus has a CEC of 200 me/100g and we calculated that the humus component of soil has aCEC of 15 meq/100g, so 100g humus/200 me x 15 meq/100 g soil = 7.5 g Humus/ 100 g soil = 7.5 %

24 me/100g x 453.6g/1 lb x 2,000,000 lb soil/Acre f.s. = 217,728,000 me/A.f.s

24 me/100g x 1000g/1kg x 2,242,000 kf soil/ha f.s. = 538,080,000 me/ha f.s.

set_3


c. CEC = 35 meq/100g soilpercent clay = 10%, clay type = X <vermiculite>percent OM = 10%<784,700,000 meq/ha f.s., 317,520,000 me/A f.s.>

To identify the clay type we need to know the me/100 g clay. First let us find the Cec for the OM. 10 gOM/100g soil x 200 me/100 g OM = 20 me/100 g soil. Now subtract that number from the total CEC of thesoil, 35 meq/100g - 20 meq/100g = 15 meq/100g for the clay component, we know that the % clay is 10%(10g clay/100g soil), therefore 15 meq/100g soil x 100g soil/10 g clay = 15 me/10g clay or 150meq/100g clay.The clay type must be vermiculite.

35 meq/100g soil x 1000g/kg x 2,242,000 kg soil/ha f.s. = 784,700,000 me/ha f.s.

35 meq/100g soil x 453.6g/ 1 lb x 2,000,000 lb soil/Acre f.s.= 317,520,000 me/A f.s.


Ca2+

Mg2+

K+

Al3+

0.001 g0.0005 g0.00025 g0.0015 g

a. Calculate CEC in meq/100g soil and cmol/kg.<2.65 cmol/kg=2.65 meq/100g>

Let's find the CEC of each of the cations, Ca = 0.001g/10g, Mg=0.0005g/10g, K=0.00025g/10g,Al=0.0015g/10g.

CEC of Ca= 0.001g/10g x 1 mole/40g x 20g/1 mole x 1000meq/1eq=0.05me/10g=0.5me/100g

CEC of Mg=0.0005g/10g x 2eq/24g x 1000meq/1eq x 10/10 = 0.416 me/100g

CEC of K=0.00025g/10g x 1eq/3eq x 1000meg/1eq x 10/10 = 0.064 meq/100g

CEC of Al=0.0015g/10g x 3eq/27g x 1000meq/1eq x 10/10 = 1.67 meq/100g

Add the CEC's together to reach 2.65 meq/100g = 2.65 cmol/kg

b. Calculate base saturation. What is the Ca 2+ saturation?<36.98%, 18.8%>

=

0.5me + 0.416meq + 0.064 me 0.98 me100g 100g 100g 100g----------------------------------------------------- x 100% = --------------- x 100% = 36.98% 2.65 meq 2.65 meq 100g 100g

Ca 2+ saturation= (0.5meq/100g)/(2.65 meq/100g) x 100% = 18.8%

c. What is the Ca:Mg:K ratio? <7.8: 6.5: 1>

0.5meq Ca 0.416meq Mg 0.064meq K 100g soil 100g soil 100g soil----------------- : ---------------------- : --------------------0.064meq 0.064meq 0.064meq 100g 100g 100g

set_3


= 7.8:6.5:1 = 40:20:1 (proper way to present the ratio)The soil has too much Mg2+ and not enough of the Ca2+ and K+.

d. Determine the quantity of aluminum for the soil above in the following units:

lbs/acre f.s. ppm tons/acre kg/ha f.s. <300> <150> <0.15> <336.3kg>

Al =0.0015g or 0.064meq 10g soil 100g soil

To find the lbs/A

0.0015 g Al3+ x 1 # Al3+

x 453.6 g soil x 2,000,000 # soil

10 g soil 453.6 g Al3+ 1 # soil A f.s. = 300 lbs Al/A f.s

ppm =mg = 0.0015 g Al x 1000 g soil x 1000 mg kg 10 g soil 1 kg 1 g

= 150 mg/kg = 150 ppm

tons/A =300 lb Al x 1 ton acre 2000 lb

= 0.15 tons/acre

kg/ha f.s. =0.0015g Al3+ x 1 kg Al x 1000g soil x 2,242,000 kg 10g soil 1000g Al 1kg ha f.s.

= 336.3 kg Al/ ha f.s.

set_3


SOME PROPERTIES OF COLLOIDS

ClayStructure

CEC (at pH7)

(me/100g)

ShrinkSwell

StickinessSurface

Area(m2/g)

Isomorph. Sub. Bondingbetween Unitstet. oct.

Kaolinite 1:1 8 NON Slight 15 Verylow

Verylow

Hydrogen

Montmorillonite 2:1 100 Very great High 750 Low High Oxygen

Vermiculite 2:1 150 Limited Mod. 400 High Veryhigh

Magnesium

Illite 2:1 30 NON Low 100 Veryhigh

Low Potassium

Chlorite 2:2 30 Limited Low 80 ? Veryhigh

Magnesiumsheet

Allophane None High NON None --- --- --- ---

Sesquioxides ? 3 NON None --- --- --- ---

Humus None 200 NON None --- --- --- ---

Muscovite 2:1 0 NON None --- Veryhigh

Verylow

Potassium

COLLOIDS

http://pss.uvm.edu/pss161/problem/COLLOIDS.html [14/07/2001 09:20:36 a.m.]

Fundamentals of Soil Science RecitationSupplemental Problems on CEC, Acidity and Liming

<Answers> to see work

1. For each problem figure out the missing information, which is labeled X.

a. CEC = X cmol/kg soil <18.5cmol/kg>percent clay = 3%, clay type = Vermiculitepercent OM = 7%

b. CEC = 12 me/100g soilpercent clay = 5%, clay type = Illitepercent OM = X% <5.25%>

c. CEC = 20 meq/100g soilpercent clay = 5%, clay type = X <Montmorilllonite clay>percent OM = 7.5%


Ca2+

Mg2+

K+

Al3+

3.2 meq1.1 meq0.3 meq0.4 meq

a. Calculate CEC in cmol kg-1. <25 cmol/kg>

b. Calculate base saturation. <92%>

c. How many grams of Mg 2+ does a 20 grams soil sample contain? <0.0132g Mg2+/ 20g soil>

c. What is the Ca:Mg:K ratio? <10.7 : 3.7 : 1>

d. Determine the quantity of calcium for the soil above in the following units:

lbs/acre ppm tons/acre kg/ha

<6400#/A f.s.> <3200ppm> <3.2tons/A f.s.> <7173.4kg/ha f.s.>

3. You want to raise the pH of your soil. A soil titration shows you need 0.25 meq CaCO3 per 10 g of soil.

a. How many lbs/acre furrow slice of Ag lime will you need? <2500 lbs/A f.s.>

prob_cec

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b. How many lbs will you need for a garden that has the dimensions of 20 ft x 20 ft? <23 # for this garden>

4. A soil was analyzed and determined to have reserve acidity at the following level: 0.0007 g/10 g soil.

a. How much lime is needed to neutralize this acid? Answer in g CaCO3/10 g soil. <0.035 g CaCO3/10 g soil>

b. How much lime is needed to neutralize this acid? Answer in tons/acre.

<3.5 tons CaCO3/A f.s.>

5. A soil was analyzed and determined to have reserve acidity at the following level: 0.009 meq/1 g of soil.

a. How much lime is needed to neutralize this acid? Answer in g CaCO3/10 g soil. <0.0045 g CaCO3/10 g soil>

b. How much lime is needed to neutralize this acid? Answer in tons/acre.

<0.45 tons CaCO3/A f.s.>

6. We titrate 100 ml of an unknown concentration of HCl acid with 0.5 N NaOH base.

a. It takes 50 mls of 0.5 N NaOH to reach the endpoint. What is the Normality of the unknown HCl acid? <0.25N>

b. How many equivalents are there in 100 ml of the above acid?

<25 meq = 0.025 eq>

c. What is the Molarity of the above acid? <0.25 M>

7. If a solution has a pH of 3.0, how many equivalents of H+ do you have in a liter? <0.001 eq/l>

b. How many grams of H+ per liter do you have? <0.001 g/l>

c. How many moles of H+ per liter do you have? <0.001 moles/l>

prob_cec

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Fundamentals of Soil Science RecitationSupplemental Problems on CEC, Acidity and Liming

<Answers>

1. For each problem figure out the missing information, which is labeled X. (You might want to look at table ofcolliod)

a. CEC = X cmol/kg soil <18.5cmol/kg>percent clay = 3%, clay type = Vermiculitepercent OM = 7%vermiculite has a CEC of 150 me/100 g and OM has 200 me/100 g therefore,3g clay/100g soil x 150 me/100 g clay = 4.5 me/100g soil and7 g OM/100 g soil x 200 me/100g OM = 14 me/ 100g soil add these together4.5 + 14 = 18.5 me/100g which is the same thing as 18.5 cmol/kg soil

b. CEC = 12 me/100g soilpercent clay = 5%, clay type = Illitepercent OM = X% <5.25%>illite has a CEC of 30 me/100g clay5 g clay/100g x 30 me/100g clay = 1.5 me/100 g soil. We know that the total CEC is 12me/100 g soil so 12 - 1.5 = 10.5 me/100 g soil is for the OM. Therefore,10.5 meq/100 g soil x 100 g/200 me (CEC for OM) = 5.25 g/100 g soil = 5.25 %

c. CEC = 20 meq/100g soilpercent clay = 5%, clay type = X <Montmorilllonite clay>percent OM = 7.5%7.5 g OM/100 g soil x 200 me/100 g OM = 15 meg (OM)/100 g soil20 - 15 = 5 meq clay/100 g soil 100 g soil/5 g clay (5%) x 5 meq/100 g soil (CEC) = 5 meq/5g soil = 100 meq/100 g soil, look this up in the colloid table and you will find montmorillonite clay


Ca2+

Mg2+

K+

Al3+

3.2 meq1.1 meq0.3 meq0.4 meq

a. Calculate CEC in cmol kg-1. <25 cmol/kg>Add all the meq together (3.2+1.1+0.3+0.4=) 5.0 meq/20 g x 5/5 = 25 me/100 g = 25 cmol/kg

b. Calculate base saturation. <92%>(3.2+1.1+0.3)/(3.2+1.1+0.3+0.4) = 4.6/5 x100 = 92%

c. How many grams of Mg 2+ does a 20 grams soil sample contain? <0.0132g Mg2+/ 20g soil>1.1 meq/20 g x 24 mg/2 meq = 13.2 mg of Mg/20 g soil13.2 mg/20 g soil x 1 g/1000mg = 0.0132 g MG/20 g soil

d. What is the Ca:Mg:K ratio? <10.7 : 3.7 : 1>Ca:Mg:K3.2/0.3 : 1.1/0.3 : 0.3/0.3 = 10.7 : 3.7 : 1

e. Determine the quantity of calcium for the soil above in the following units:

prob_cec

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lbs/acre ppm tons/acre kg/ha

<6400#/A f.s.> <3200ppm> <3.2tons/A f.s.> <7173.4kg/ha f.s.>

3.2 meq Ca2+/20g soil x 40 mg/2meq x 1g/1000mg x 2,000,000 lbs/A.f.s = 6400 #/A.f.s.3.2 meq Ca2+/20g soil x 40 mg/2meq x 1g/1000mg x 2,000,000 lbs/A.f.s x (A/lbs)/2= 3200ppm3.2 meq Ca2+/20g soil x 40 mg/2meq x 1g/1000mg x 2,000,000 lbs/A.f.s x 1 ton/2000 lbs = 3.2 tons/A.f.s.3.2 meq Ca2+/20g soil x 40 mg/2meq x 1g/1000mg x 2,242,000 kg/ha = 7173.4 kg/ha

3. You want to raise the pH of your soil. A soil titration shows you need 0.25 meq CaCO3 per 10 g of soil.a. How many lbs/acre furrow slice of Ag lime will you need? <2500 lbs/A f.s.>0.25 meq CaCO3 /10g soil x 100 mg/2 meq x 1g/1000mg x 2,000,000 #/A.f.s. = 2,500 #/A.f.s

b. How many lbs will you need for a garden that has the dimensions of 20 ft x 20 ft? <23 # for this garden>2500lbs/21,780 ft3 x ?/200ft3 ?=23.0 lbs

4. A soil was analyzed and determined to have reserve acidity at the following level: 0.0007 g/10 g soil.a. How much lime is needed to neutralize this acid? Answer in g CaCO3/10 g soil. <0.035 g CaCO3/10 g soil>

0.0007 g H+/10g x 100g/2eq = 0.035 g/10g

b. How much lime is needed to neutralize this acid? Answer in tons/acre. <3.5 tons CaCO3/A f.s.>

0.0007 g H+/10g x 100g/2eq = 0.035 g/10g x 2,000,000 = 7000 #/A=3.5 tons/A

5. A soil was analyzed and determined to have reserve acidity at the following level: 0.009 meq/1 g of soil.a. How much lime is needed to neutralize this acid? Answer in g CaCO3/10 g soil. <0.0045 g CaCO3/10 g soil>0.009 meq/1 g soil x 100 mg/2 meq x 1g/1000mg = 0.00045g/1g x 10/10 = 0.0045 g CaCO3/10 g

b. How much lime is needed to neutralize this acid? Answer in tons/acre. <0.45 tons CaCO3/A f.s.>0.0045 g CaCO3/10 g soil x 2,000,000 = 900#/A = 0.45 tons/A.f.s.

6. We titrate 100 ml of an unknown concentration of HCl acid with 0.5 N NaOH base.a. It takes 50 mls of 0.5 N NaOH to reach the endpoint. What is the Normality of the unknown HCl acid? <0.25N>100 ml HCl base: N 50 ml x 0.5 M/100 = 0.25 NNa x mla = Nb x mlb

b. How many equivalents are there in 100 ml of the above acid? <25 meq = 0.025 eq>100ml x 0.25 = 25 meq = 0.025 eq

c. What is the Molarity of the above acid? <0.25 M>0.25 N = 0.25 M when 1 mole has 1 valent change

7. If a solution has a pH of 3.0, how many equivalents of H+ do you have in a liter? <0.001 eq/l>

b. How many grams of H+ per liter do you have? <0.001 g/l>

c. How many moles of H+ per liter do you have? <0.001 moles/l>

prob_cec

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Fundamentals of Soil Science RecitationProblem Set 4: Acidity and Liming

Bring your questions on your problem set calculations to recitation. <Answers> to see the work

1 a. Burlington receives 30 to 40" of rain and snow per year. If 36 inches of rain fell on one acre this year, which had a pH of 4.0,how much limestone would you have to add to neutralize it? (Answer in lbs/acre f.s. and kg/ha f.s.) <40.8 #/A f.s., 45.7 kg/ha f.s.>

b. Soil in the above problem was tested for reserve acidity. The UVM Agricultural and Environmental Testing Lab found 2 me H+

per 100 grams of soil. How much ag limestone (CaCO3) is need to neutralize the reserve acidity. Assume your limestone is 100%pure, which is true for much of the limestone mined in Vermont. (Answer in lbs/acre f.s. and kg/ha f.s.) <2000#/ A f.s., 2242 kg/haf.s.>

c. Using info from problem 1b above determine limestone needed for a 30' x 30' garden plot (standard 6 inch depth). <41.3 #/ gardenplot>

d. You have decided to lime with ashes from hardwoods you burned last winter instead of CaCO3 in problem 1c above. UVM's SoilTest lab conducted a titration to determine the CCE (Calcium Carbonate Equivalent) of your wood ashes, which was 0.70 of Aglime. How much more woodashes would you need to use? <59 # total or 18 more #>



b. How many equivalents are there in 100 ml of the above acid? <0.05eq>

c. What is the Molarity of the above acid? <0.5M>

d. If the above acid was found in 100 g of soil, how much limestone would be needed neutralize it? Answer in lbs CaCO3 per acrefurrow slice.

<25 tons/A f.s.>

Notes:

2,000,000 lbs soil/ A f.s.2,242,000 kgs soil/ ha f.s.

In conversion of one substance to another you must work throughmeq or eq to relate the two

ml x N = meq mla x Na =mlb x Nb because meqa = meqb

N = nM Normality = n # of electron transfering in the reaction (valance xmoles) x Molarity

NEED MORE PRACTICE WITH CHEMISTRY? Then Try these:

1. What is the molecular weight and the equivalent weight of the following two groups of substances:

prob_set4


Group a. NaOH CaCO3 KCl CaCl2 K2SO4 Group b. Ca2+ Mg2+ Al3+ H+ K+

g mw 40 100 74 110 174 40 24 27 1 39

g eq wt 40 50 74 55 87 20 12 9 1 39

2. How many grams must be weighed out to make 1 liter of group a above at the concentration of 1 N, 0.01 N, and 2 N.

<1 N: 40 50 74 55 87>

<0.01 N: 0.4 0.5 0.74 0.55 0.87>

<2 N: 80 100 148 110 174>

3. How many equivalents are there of group a in question 1 above in a one liter solution with one normal concentration? How manymilliequivalents are there? <1 eq, 1000 meq>

4. How many milliequivalents are there in 1 ml of a normal solution of group a above? <1 meq>

5. How many milliequivalents are there in 1 ml of a 0.01 normal solution of group a above? <0.01 meq>

6. If you had 500 mls of a 1 N solution of group a above, how many milliequivalents would you have? <500 meq>

7. If you had 500 mls of a 0.02 N solution of group a above, how many milliequivalents would you have? <10 meq>

8. One meq of HCl contains how many meq of H+ ions? <1 meq>

9. How many meq of HCl would be neutralized by 30 ml of 0.1 N NaOH? <3 meq>

10. How many eq are present in 10 grams of calcium? <0.5 eq>

11. How many eq are present in 10 grams of CaCO3? <0.2 eq>

12. How many grams of sodium are in 100 meq? <2.3 g>

13. How many grams of group b above are there in 10 meq? <0.2 g, 0.12 g, 0.09 g, 0.01 g, 0.39 g>

prob_set4


Fundamentals of Soil Science RecitationProblem Set 4: Acidity and Liming


1 a. Burlington receives 30 to 40" of rain and snow per year. If 36 inches of rain fell on one acre this year, which had a pH of 4.0, howmuch limestone would you have to add to neutralize it? (Answer in lbs/acre f.s. and kg/ha f.s.) <40.8 #/A f.s., 45.7 kg/ha f.s.>

First let's convert the pH into something we can use,

pH 4 = 0.0001 moles H+

literor 0.001 g

H+ or

liter 0.0001 eq H+

= liter

0.0001 eq H+

1000ml

Now convert the volume of rain to determine how much fell on a liter basis.

36"= 3'/acre or 3' over 43560 ft2=3'x 43560 ft2=130,650 ft3 of rain =

130,650 ft3 x (30.48 cm/1ft)3 =130,650 ft3 x 28,317 cm3/1ft3 = 3,700,467,715 cc = 3,700,467,715 ml = 3,700,467,715ml x1liter/1000ml = 3,700,467.7 liters of rain.then 0.0001 eq H+/1liter = ? eq H+/3,700,467.7 liter, ? = 370.05 eq H+/Acre

370.05 eq H+

x 1 eq CaCO3 x 100 g CaCO3 x 1 kg CaCO3 x 2.471 A

acre f.s. 1 eq H+ 2 eq CaCO3 1000 g CaCO3 1 ha f.s.

= 45.7 kg/ha f.s.

or

370.05 eq H+

x 1 eq CaCO3 x 100g CaCO3 x 1 # CaCO3

acre f.s. 1 eq H+ 2 eq CaCO3 453.6g CaCO3= 40.8 lbs CaCO3/A f.s.

b. Soil in the above problem was tested for reserve acidity. The UVM soil test lab found 2 me H+ per 100 grams of soil. How much aglimestone (CaCO3) is need to neutralize the reserve acidity. Assume your limestone is 100% pure, which is true for Vermont minedlimestone.(Answer in lbs/acre f.s. and kg/ha f.s.) <2000#/ A f.s., 2242 kg/ha f.s.>

2 meg H+ x 1 me Ca+

x 100 mg CaCO3 x 1 g CaCO3 x 1 # CaCO3 x 453.6 g soil x 2,000,000 lb soil100 g soil me H+ 2 meq CaCO3 1000 mg CaCO3 453.6g CaCO3 1 lb soil A f.s.

= 2000 lb./A f.s

2 meg H+ x 1 me Ca+

x 100 mg CaCO3 x 1 g CaCO3 x 1 kg CaCO3 x 1000 g soil x 2,242,000 kg soil100 g soil me H+ 2 meq CaCO3 1000 mg CaCO3 1000 g CaCO3 1 kg soil ha f.a.

= 2,242 kg/ha f.s.

c. Using info from problem 1b above determine limestone needed for a 30' x 30' garden plot. <41.3 #/ garden plot>

1 Acre f.s. = 43560 ft2 x 0.5 ft = 21,780 ft3 , the garden is 30'x30'x0.5'=450 ft3

if we needed a rate of 2000#/acre f.s., but have only 450 ft3 then cross multiply, 2000#/21780 ft3 = ? #/450 ft3 ?=41.3 # lime for thegarden plot.

d. You have decided to lime with ashes from hardwoods you burned last winter instead of CaCO3 in problem 1c above. UVM's Soil Testlab conducted a titration to determine the CCE (Calcium Carbonate Equivalent) of your wood ashes, which was 0.70 of Ag lime. Howmuch more woodashes would you need to use? <59 # total or 18 more #>

if we added the same weight of woodash as the lime recommendation we would have added 41.3 lb x 0.70 =28.91# CaCO3 whichwe know is not enough. 41.3 lb/1 CCE = ? lb/(1/0.70) CCE = 59.0 lb woodash or 18 # more woodash would be needed.



meqa=meqb and mla x Na = mlb x Nb therefore 100ml x ?N = 50 ml x 1.0, ?N = 0.5 N

set_4


b. How many equivalents are there in 100 ml of the above acid?<0.05eq>

0.5 N x 100 ml = 50 meq x 1 eq/1000 meq = 0.05 eq

c. What is the Molarity of the above acid?<0.5M>

N= nM = (valence charge x moles) x M

0.5 M x 1(valence charge) x 1 (mole) = 0.5 N

d. If the above acid was found in 100 g of soil, how much limestone would be needed neutralize it? Answer in lbs CaCO3 per acrefurrow slice.<25 tons/A f.s.>

0.05 eq/100g x 1 eq Ca+/1 eq H+x 100g CaCO3/2 eq x 1# CaCO3/453.6 g x 453.6 g soil/1# x 2,000,000 # soil/ ha f.s. x 1 tonCaCO3/2000#= 50,000# CaCO3/ A.f.s.50,000#/A.f.s x 1 ton/2,000 # = 25 tons/A (this is really too much to add at any one time!, usually would not add more than 4 tonsat one time)

Notes:2,000,000 lbs soil/ A f.s.2,242,000 kgs soil/ ha f.s.In conversion of one substance to another you must work through meq or eq to relate the two ml x N = meq mla x Na = mlb x Nb becausemeqa = meqb N = nMNormality = n # of electron transfering in the reaction (valance x moles) x Molarity

NEED MORE PRACTICE WITH CHEMISTRY? Then Try these:

1. What is the molecular weight and the equivalent weight of the following two groups of substances:

Groupa.

NaOH CaCO3 KCl CaCl2 K2SO4 Groupb.

Ca2+ Mg2+ Al3+ H+ K+

g mw 23+16+1=40 40+12+3(16)=100 39+25=74 40+2(35)=110 2(39)+32+4(16)=174 40 24 27 1 39

g eqwt

40 50 74 55 87 20 12 9 1 39

2. How many grams must be weighed out to make 1 liter of group a above at the concentration of 1 N, 0.01 N, and 2 N.

<1 N: 40 50 74 55 87>

<0.01 N: 0.4 0.5 0.74 0.55 0.87>

<2 N: 80 100 148 110 174>

3. How many equivalents are there of group a in question 1 above in a one liter solution with one normal concentration? How manymilliequivalents are there? <1 eq, 1000 meq>

meq = ml x N1 liter = 1000 ml 1000ml x 1 N = 1000 meq = 1 eq for all

4. How many milliequivalents are there in 1 ml of a normal solution of group a above? <1 meq>

1 ml of 1 N = 1 ml x 1 N = 1 meq for all

5. How many milliequivalents are there in 1 ml of a 0.01 normal solution of group a above? <0.01 meq>

1 ml x 0.1 N = 0.1 meq for all

6. If you had 500 mls of a 1 N solution of group a above, how many milliequivalents would you have? <500 meq>

500 ml x 1 N = 500 meq

7. If you had 500 mls of a 0.02 N solution of group a above, how many milliequivalents would you have? <10 meq>

set_4


ml x N = meq = 500 x 0.02 = 10 meq

8. One meq of HCl contains how many meq of H+ ions? <1 meq>

1 meq HCl = 1 meq H+

9. How many meq of HCl would be neutralized by 30 ml of 0.1 N NaOH? <3 meq>

30 ml x 0.1 N = 3 meq base = 3 meq acidNa x mla = Nb x mlbmeqa = meqb

10. How many eq are present in 10 grams of calcium? <0.5 eq>

10 g Ca2+ = ? eq40 g/2 eq = 10 g/ X eq or 2 eq/40 g = Xg/ 10 gX= 0.5 eq

11. How many eq are present in 10 grams of CaCO3? <0.2 eq>

CaCO3 10 g = ? eq2 eq/ 100g = X eq/10 g = 0.2 eq

12. How many grams of sodium are in 100 meq? <2.3 g>

1 eq/23 g = 1000 meq/23 g23 g/1000 meq = Xg/ 100 mg = 2.3 g

13. How many grams of group b above are there in 10 meq? <0.2 g, 0.12 g, 0.09 g, 0.01 g, 0.39 g>

g=? 10 meqCa2+, 40 g/2000 meq = Xg/10 meq = 2.2 gMg2+, 24 g/2000 meq = Xg/ 10 meq = 0.12 gAl3+, 27 g/3000 meq = Xg/10 meq = 0.09 gH+, 1 g/1000 meq = Xg/10 meq = 0.01gK+, 39 g/1000 meq = Xg/10 meq = 0.39 g

set_4


Fundamentals of Soil Science RecitationProblem Set 5: Soil Fertility

Bring your questions on your problem set calculations to recitation. <Answers> to see the work

1. Given the following information, please calculate the increase in mineralized or microbial availablenitrogen when you increase your soil organic matter content from 4% to 8% in a soil. Answer in lbs N/Af.s.

_________lbs N/A f.s. <80>

If you increase SOM from 4% to 8% what is the change in mineralize N. Assume that 1/20 of SOM is organic N. The rate of N mineralization from the organic N in organic matter is 1-5% a year. You use 2%. There are 2,000,000 lbs of soil per acre furrow slice.

2. a. Calculate the amount of nitrogen you will get from dairy manure supplied by your 5 dairy cows.You need to fertilize 5 acres of mixed vegetables for which the soil test report recommends 160 lbs of N/A f.s.

Your Dairy Manure (DM) has an analysis (with losses from storage) of 7 lbs N/ ton of manure (7-5-11in lbs/ton). Each lactating cow produces about 20 tons of manure/year. Assume you are applying the manure uniformly over the 5 acres.__________lbs of N applied from manure/A f.s. <140>

b. What percentage of SOM must you have to have in your soil to supply the rest of the 160 lbs N/ A f.sfor mixed vegetables that was not supplied by your dairy manure.__________% SOM <1>

3. If you were the same vegetable grower in problem 2 above, but you didn't have any dairy cows, howcould you supply N needs using cover crops and organic soil nitrogen mineralized from your percent soilorganic matter. Use two books to help you: 1. Managing Cover Crops Profitably a SustainableAgriculture Research and Education (SARE) publication on reserve at Bailey-Howe and 2. your textbookby Brady and Weil. Determine a nitrogen supplying cover crop to use in your rotation with mixedvegetables. Determine how much nitrogen your cover crop would supply and the % SOM you mustmaintain in your soil to supply the balance.__________lbs of N supplied from cover crop/A f.s. <82 vetch/rye>__________% SOM <3.9>

prob_set5

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Fundamentals of Soil Science RecitationProblem Set 5: Soil Fertility


1. Given the following information, please calculate the increase in mineralized or microbial availablenitrogen when you increase your soil organic matter content from 4% to 8% in a soil. Answer in lbs N/Af.s. <80 lbs N/A f.s.> If you increase SOM from 4% to 8% what is the change in mineralize N. Assume that 1/20 of SOM is organic N. The rate of N mineralization from the organic N in organic matter is 1-5% a year. You use 2%. There are 2,000,000 lbs of soil per acre furrow slice.first let's calculate the available nitrogen in a soil with 4% organic mater2,000,000 # soil/A f.s. x 4 # OM/100 # soil x 1# N total/20 # OM x 2# available N/100 # total N =80# avail N/A f.s.then let's calculate the available nitrogen in a soil with 8% organic mater2,000,000 # soil/A f.s. x 8 # OM/100 # soil x 1# N total/20 # OM x 2# available N/100 # total N =160# avail N/A f.s.160# avail N/A f.s. - 80# avail N/A f.s. = 80# avail N/A f.s. increase

2. a. Calculate the amount of nitrogen you will get from dairy manure supplied by your 5 dairy cows.You need to fertilize 5 acres of mixed vegetables for which the soil test report recommends 160 lbs of N/A f.s. Your Dairy Manure (DM) has an analysis (with losses from storage) of 7 lbs N/ ton of manure (7-5-11in lbs/ton). Each lactating cow produces about 20 tons of manure/year. Assume you are applying the manure uniformly over the 5 acres. ______lbs of N applied from manure/A f.s. <140>

5 cows x 20 tons manure/year = 100 tons manure/year7 #N/1 ton = how much N applied over 5 acre/100 tons manure applied700 # N applied over 5 acres or 140 # N/A f.s.the soil test recommendation is for 160 # of N, you are only applying 140 #/A, therefore you stillneed 20# of N/A

b. What percentage of SOM must you have to have in your soil to supply the rest of the 160 lbs N/ A f.sfor mixed vegetables that was not supplied by your dairy manure. __________% SOM <1>We know that you need 20 #N more per acre furrow sliceIf 4%/80# avail N (from question 1)= x%/20# avail Nx=1%Therefore, for each 1% OM, 20#/Af.s. of N is available, you need 20#N/acre or 1% OM for soil.

3. If you were the same vegetable grower in problem 2 above, but you didn't have any dairy cows, howcould you supply N needs using cover crops and organic soil nitrogen mineralized from your percent soilorganic matter. Use two books to help you: 1. Managing Cover Crops Profitably a SustainableAgriculture Research and Education (SARE) publication on reserve at Bailey-Howe and 2. your textbookby Brady and Weil. Determine a nitrogen supplying cover crop to use in your rotation with mixedvegetables. Determine how much nitrogen your cover crop would supply and the % SOM you must

prob_set5

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maintain in your soil to supply the balance.__________lbs of N supplied from cover crop/A f.s. <82 vetch/rye>__________% SOM <3.9>You can choose any cover crop you like.Let's try vetch. Brady (page 332) says 50 - 125 #N/A suppliedvetch/oats mix SARE (page 21) says 98 - 145 #N/A suppliedvetch/rye mix SARE says 65-98 #N/A supplied

winter rye has a mild herbicide effect (bonus! helps control weeds)oats die back over winter (another bonus, oats will act as a soil mulch leaving the vetch for nextseason)

You need 160# N/A f.s. and with mixed vegetable herbicide effect is important.How to choose which mix and amont of nitrogen. Soil type supports crop, sand acid soil has lessnitrogen than silt loam

If you use Vetch/rye mix it will supply 82 # N/A f.s. (65+98=163/2=82) Brady says average is 87.5 #N/ASo 160# - 82# = 78 # N/A still needed.

1% OM/20# N/A f.s. = x%/78#N x=3.9%3.9% OM to support this need

prob_set5


Fundamentals of Soil Science RecitationProblem Set 6: Soil Testing

Bring your questions on your problem set calculations to recitation. Answers are not included becausethere is no one correct answer to this problem set. to see sample work

You are part of an effort to establish the Green Mountain Ag-Environmental Center that will teach peopleecological food production techniques and the integration of environmental resource conservation andagriculture. Since you have had PSS 161 you are responsible for figuring out how to fertilize your acid, infertile,low OM, sandy loam soil for this year's commercial crop, which is 3 acres of sweet corn.

The staff members have agreed that you will use only certified organic materials, but money is tight. Most of theinfo you need is below or in the UVM "Guidelines for Organic Fertilization" handout produced by UVM's SoilTest Lab. Please determine how to complete this task with minimum expense. You need to bring yourrecommendations and budget to the next "staff" meeting on Monday. Good luck.

I ask that you use organic fertilizers here because many of them contain N, P and K, which makes for a moreinteresting and complicated exercise. If you can do calculations for fertilizers containing more than one nutrientyou can certainly do them for fertilizers containing only one nutrient.

VERY, VERY, VERY HELPFUL HINTS

To recommend fertilizers START with N nutrient needs. After N needs are calculated, then calculatehow much P2O5 and K2O were added as "hitch-hikers" (if you used a material containing more nutrientsthan just N). If any additional P2O5 or K2O is needed make another fertilizer choice. Look for fertilizersthat do not contain nitrogen.

To figure out the amounts of fertilizers you need, use the ratio of your known lbs of nutrient/100 lbs offertilizer (from the fertilizer percent analysis listed) to the known lbs of nutrient needed/unknown amountin lbs of fertilizer you want to use. The numerators of each ratio must have the same units, and thedenominators of each ratio must have the same units. You then can cross multiple and solve for yourunknown.

To figure out how much of a nutrient has been added by a specific fertilizer material you also need usethe ratio of your known lbs of nutrient/100 lbs of fertilizer to the unknown lbs of nutrient added/knownamount in lbs of fertilizer you used. Once again, if the numerators and denominators are in the correct unitsyou can cross multiple and solve for your unknown.

Finally, you should sum the total amount of each nutrient added by each fertilizer material used. Thiscalculation will tell you if you have completed the task.

Please be aware of costs!

MATH IS FUN AND USEFUL!

Soil Test Info

Your Soil Test Result show you are very low in all nutrients.

UVM's Soil Test Recommendations for Sweet Corn:

Nitrogen (N): 140 lbs/A f.s. Total Needed40 lbs very soluble N minimum for early crop

prob_set6


Phosphorus (P2O5): 160 lbs/A f.s.For Very Low Soil Test Values

Potassium (K2O): 160 lbs/A f.s.

For Very Low Soil Test Values Limestone: 4 tons/A f.s. to pH 6.8 Use Dolomitic Limestone to Improve Ca and Mg Soil

Test Levels

Fertilizer Info

You have access to fresh animal manures with minimum expense from your supportive neighbors.

Through the NOFA (Northeast Organic Farming Association) you can buy the following certified organicfertilizers at bulk rates (actual 2000 prices):

Analysis Green Sand 0-1-7 3=Mg,

20=Fe$9.25/50 lb bag $237.50/ton

Black Rock Phosphate 0-30-0** $9.15/50 lb bag $265.50/ton Blood Meal 12-0-0 $28.65/50 lb bag Bone Meal 0-11-0 $16.60/50 lb bag Peanut Meal 8-1-0 $12.25/50 lb bag

Composted Chicken Manure 5-3-3 $7.90/50 lb bag Fish Emulsion 2-4-0.5 $16.50/gal $55.00/5 gal $56.00/5 gal Pro-Gro Blend 5-3-4 $10.85/50 lb bag $335.00/ton Custom Blend 5-5-5 $10.85/50 lb bag $350.20/ton

** See UVM's Guidelines for Percent Available P2O5

If you want to use other fertilizers you will need to figure out the costs yourself. Agway, Gardener's SupplyCompany, Farm Suppy Depot and other farm and garden centers can give you quotes on prices.

prob_set6


Fundamentals of Soil Science RecitationProblem Set 6: Soil Testing

Sweet corn needs from the UVM's Soil Test Recommendations for Sweet Corn: 100#/A 40# N soluble/A f.s 160 # P2O5/A f.s. 160 # K2O/A f.s. 4 tons dolomitic limestoneUsing the info from the UVM "Guidelines for Organic Fertilization" handout produced by UVM's SoilTest Lab let's choose sheep manure (SM):

100# SM = ____x# SM = 1# SM 100# N/A needed

10,000 SM or 50 tons to meet N needs

Hitchhikers:

0.3# P2O5 = x P2O5 applied100# SM 10,000# SM

x=30# P2O5 applied (130 # P2O5 still needed)

1.0# K2O = x K2O applied100# SM 10,000# SM

x = 100 # K2O applied (60 # K2O still needed)

need to choose another fertilizer that does not have nitrogen

woodash (WA):100# WA = x# WA 5# K2O 60# K2O

x=1200# K2O/A

Hitchhiker:

2# P2O5 = x# P2O5100# WA 1200#

WA = 24# P2O5 (106# P2O5 still needed)

so we still need more P2O5 and could use a fertilizer with only P, let's use black rock phosphate (it is lessexpensive and has only P, 0-30-0, however, only the available P should be used, 0-2-0

100# = x#/A 2# P2O5 106# P2O5

x=5300# rock phosphate/A

Summary:

three acres price

10,000 # sheep manure/acre 30,000 # $0

1200# woodash 3,600# $0

5300 # rock phosphate/A 15,900 # $2111

Dolomitic Limestone 8000#-1000#=7000/acre needed=3.5 tons 21,000# $600

Blood Meal 333#/A 1,000# $573

You are part of an effort to establish the Green Mountain Ag-Environmental Center that will teach peopleecological food production techniques and the integration of environmental resource conservation andagriculture. Since you have had PSS 161 you are responsible for figuring out how to fertilize your acid, infertile,low OM, sandy loam soil for this year's commercial crop, which is 3 acres of sweet corn.

prob_set6


The staff members have agreed that you will use only certified organic materials, but money is tight. Most of theinfo you need is below or in the UVM "Guidelines for Organic Fertilization" handout produced by UVM's SoilTest Lab. Please determine how to complete this task with minimum expense. You need to bring yourrecommendations and budget to the next "staff" meeting on Monday. Good luck.

I ask that you use organic fertilizers here because many of them contain N, P and K, which makes for a moreinteresting and complicated exercise. If you can do calculations for fertilizers containing more than one nutrientyou can certainly do them for fertilizers containing only one nutrient.

VERY, VERY, VERY HELPFUL HINTS

To recommend fertilizers START with N nutrient needs. After N needs are calculated, then calculatehow much P2O5 and K2O were added as "hitch-hikers" (if you used a material containing more nutrientsthan just N). If any additional P2O5 or K2O is needed make another fertilizer choice. Look for fertilizersthat do not contain nitrogen.

To figure out the amounts of fertilizers you need, use the ratio of your known lbs of nutrient/100 lbs offertilizer (from the fertilizer percent analysis listed) to the known lbs of nutrient needed/unknown amountin lbs of fertilizer you want to use. The numerators of each ratio must have the same units, and thedenominators of each ratio must have the same units. You then can cross multiple and solve for yourunknown.

To figure out how much of a nutrient has been added by a specific fertilizer material you also need usethe ratio of your known lbs of nutrient/100 lbs of fertilizer to the unknown lbs of nutrient added/knownamount in lbs of fertilizer you used. Once again, if the numerators and denominators are in the correct unitsyou can cross multiple and solve for your unknown.

Finally, you should sum the total amount of each nutrient added by each fertilizer material used. Thiscalculation will tell you if you have completed the task.

Please be aware of costs!

Soil Test InfoYour Soil Test Result show you are very low in all nutrients.UVM's Soil Test Recommendations for Sweet Corn:

Nitrogen (N): 140 lbs/A f.s. Total Needed 40 lbs very soluble N minimum for early cropPhosphorus (P2O5): 160 lbs/A f.s.

For Very Low Soil Test ValuesPotassium (K2O): 160 lbs/A f.s.

For Very Low Soil Test ValuesLimestone: 4 tons/A f.s. to pH 6.8 Use Dolomitic Limestone to Improve Ca and Mg Soil

Test Levels

Fertilizer InfoYou have access to fresh animal manures with minimum expense from your supportive neighbors.Through the NOFA (Northeast Organic Farming Association) you can buy the following certified organicfertilizers at bulk rates (actual 2000 prices):

Analysis

prob_set6


Green Sand 0-1-7 3=Mg,20=Fe

$9.25/50 lb bag $237.50/ton

Black Rock Phosphate 0-30-0** $9.15/50 lb bag $265.50/ton Blood Meal 12-0-0 $28.65/50 lb bag Bone Meal 0-11-0 $16.60/50 lb bag Peanut Meal 8-1-0 $12.25/50 lb bag

Composted Chicken Manure 5-3-3 $7.90/50 lb bag Fish Emulsion 2-4-0.5 $16.50/gal $55.00/5 gal $56.00/5 gal Pro-Gro Blend 5-3-4 $10.85/50 lb bag $335.00/ton Custom Blend 5-5-5 $10.85/50 lb bag $350.20/ton

** See UVM's Guidelines for Percent Available P2O5If you want to use other fertilizers you will need to figure out the costs yourself. Agway, Gardener's SupplyCompany, Farm Suppy Depot and other farm and garden centers can give you quotes on prices.

prob_set6


University Of Vermont Extension System - Agricultural and Environmental Testing LabGUIDELINES FOR ORGANIC FERTILIZATION

Soil fertility is a function of the biological, physical and chemical characteristics of soil. An organic soil fertility programshould consider all of these inter-related factors in order to optimize and sustain crop production.

Soil tests are useful for monitoring soil organic matter content, which influences the physical and biological quality of soil.Soil tests also estimate the level of chemical nutrients in the soil that are available to plants. This helps determine the quantityand type of soil amendments needed for good crop growth.

Organic matter maintenance is essential to organic agriculture. Generous additions of compost, animal or green manures areneeded to fuel soil microbes, the byproducts of which bind soil particles together to improve the physical condition, orstructure of soil. Good structure promotes root growth and thus enhances plant retrieval of soil nutrients.

Decaying organic matter releases a slow, steady supply of nutrients to a crop so long as soil temperature, moisture, andaeration support microbial activity (as when soil is properly drained and well-warmed). When this release of nutrients, ormineralization, is low, as when soils are cool, fertilizing with soluble forms of nutrients may benefit crops. This is why somesoluble phosphorus (P) and nitrogen (N) should be banded, or placed near the roots of crops early in the growing season. Forexample, use bone meal and dried blood to provide soluble P and N, respectively, or use a commercial organic fertilizer blend.

Rock powders can be used, along with organic matter, to build up and balance soil reserves of plant nutrients, However, theseusually are not very soluble nutrient sources, and are not effective for treating short-term nutrient deficiencies. Using somesoluble fertilizers may be advisable while building soil reserves of plant nutrients with rock powders and organic matter.

Limestone is a widely used rock powder. It raises the soil pH and provides calcium (Ca) and varying amounts of magnesium(Mg). When Mg tests below about 50 ppm, high-Mag limestone, or dolomite, should be used for liming. If Mg is above about100 ppm, use materials according to the desired base saturation ratio of 20:4:1 for Ca:Mg:K in the soil, but remember, this goalis only a ballpark figure and is definitely secondary to establishing the proper pH of 6 to 7 for most crops, and adding nutrientsshown to be deficient by a soil test.

Nitrogen (N) Only some of the N in manures and compost becomes available to plants in the season after incorporation, therest is released over time. A ton of compost containing 1% N can provide about 5 to 10 lb of N per acre. Similarly, about 10 to10 lb N/acre is released from each 1% of soil organic matter.

The release of N from organic materials is faster late in the season when soil is warm, and may not be well timed to crop needs.Annual crops need N most intensely about 3 to 4 weeks after emergence or transplanting. Sidedressing, or spreading soluble Nalong the crop row at this time is often advisable. Because soluble organic N fertilizers are expensive, it pays to use somewhatlower rates than recommended for synthetic fertilizers. A sidedressing of 25 lb N/acre is reasonable for many crops growing ina fairly fertile soil. That requires 200 lb dried blood, 400 lb soy or cottonseed meal, or the equivalent.

Phosphorus (P) is low in many New England soils, and often limits crop growth early in the season. Soils with just a few ppmavailable P usually require substantial applications of fertilizer P. Hard rock phosphate contains about 2% available phosphate.Soft, or colloidal, rock phosphate contains about 3% available phosphate. Thus, a ton of these materials provides only 40 to 60lb available phosphate/acre. Bone meal contains several times more available P by weight, but is more expensive. With soilslow in P, it helps to work a portion of the P fertilizer into the crop row rather than to broadcast it. Maintain a pH of 6 to 7 withlimestone to maximize P availability. Compost and manures tend to supply less P than N or K.

Potassium (K) may be supplied by large additions of organic residues like manure and compost. It is only slowly availablefrom granite dust or greensand, which are applied at 3-5 tons to the acre to build up K reserves. Wood ashes contain soluble K,but must be used with caution because they will raise pH rather rapidly and can be caustic. The liming effect of 1 pound ofashes is roughly equal to 2/3 of a pound of limestone. No more than 2 ton of ashes per acre should probably applied at once,and only then if called for by low pH, low K and sufficient Mg. Sul-po-mag, a natural mineral, is the K fertilizer of choicewhen Mg is also needed, as it contains 22% potash.

Magnesium (Mg) is most economically applied as dolomitic lime, but when liming is not required and soil Mg tests below 50pm, use other Mg sources such as sul-po-mag or epson salts. Sul-po-mag is the better choice if K is also needed, as it is lessexpensive than Epsom salts. However, Epsom salts can be applied as a foliar spray to alleviate Mg deficiency. Dissolve 1.5 lbper 10 gal water and spray at weekly intervals.

Agricultural and Environmental Testing Lab

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Minor elements are best supplied to crops by regular additions of organic residues to the soil. Seaweed extracts may alsosupply trace minerals. In Vermont, soils are commonly low in boron (B), and if soil tests indicate less than 0.3 ppm, B may beneeded for crops that readily suffer from B deficiency, such as crucifers. No more than 1 to 2 lb/acre of B should be applied,usually mixed in with other fertilizers. Solubor (20% B) and Borax (11% B) are organically permitted. Excess levels of B aretoxic to plants, and some crops, such as beans, peas and cucurbits can be injured when planted after boron has recently beenapplied.

ORGANIC FERTILIZERSApproximate Nutrient Content (by Weight) of Organic Residues

(Nutrient content varies with origin and handling)

N % P205% K20 % Relative Availability

Alfalfa Pellets 3 0.5 3 slow

Dried Blood 13 2 .5 med/rapid

Bone Meal (raw) 2-6 15-27 0 slow

Bone Meal (steamed) .5-4 18-34 0 slow/med

Cocoa shells 1-2 1 2-3 slow

Compost-unfortified 1-3 .5-1 1-2 slow

Compost-fortified blends 3-5 3-4 3-5 slow/med

Cottonseed meal 6 2 2 slow/med

Fish emulsion 4-5 1-2 1-2 rapid

Bat Guano 6 9 2 med

Manure (fresh) - dairy .5 .2 .5 med

horse .6 .2 .5 med

sheep 1 .3 1 med

poultry 1-3 1-2 .5-2 med/rapid

Pomace (fresh apple) .3 .1 .2 slow

Soybean meal 6-7 1-2 2 slow/med

Tankage (dry) 6-7 10-14 0 medium

Wood ashes 0 1-3 3-7 rapid

Approximate Nutrient Content (by Weight) of Some Mineral Deposits(Nutrient content varies with origin, availability depends largely on fineness of grid)

N % P205% K20 % Relative Availability



Colloidal Phosphate 0 18-25* 0 slow

Granite dust 0 0 3-5 very slow

Greensand 0 0 4-9 very slow

Rock phosphate 0 20-32** 0 slow

Sodium Nitrate 16 0 0 rapid

Sul-Po-Mag 0 0 21 11 Mg rapid

Epsom Salts 10 Mg rapid

Dolomitic lime 6 -14 Mg slow

* about 3% available**about 2% available

For more informationA variety of gardening and farming leaflets are available from the University of Vermont Extension System. For a catalog,write to:University of Vermont Extension SystemPublications OfficeAgricultural Engineering BuildingBurlington VT 05405-0004

Cornell University also has numerous fact sheets on soil, crop and pest management that are of use to both conventional andorganic growers. For a catalog, write to:Extension PublicationsDistribution Center GP7 Business and Technology ParkIthaca NY 14850

In addition, the following texts are suggested reading for those interested in organic soil fertility management:

The Soul of the Soil, A Guide to Ecological Soil Management by Grace Gershuny and Joseph Smillie. GAIA Services, Box 84,RFD 3, St. Johnsbury, VT 05819

Fertile Soil, A Grower's Guide to Organic and Inorganic Fertilizers by Robert Parnes. AgAcess, P.O. Box 2008, Davis, C05617

Green Manuring, Principles and Practice by Otto Schmid and Ruedi Klay. Woods End Agricultural institute, Rt.. 2 Box 1850,Mt. Vermont, ME 04352

The New Organic Grower by Elliot Coleman. Chelsea Green publishing, P.O. Box 283, Chelsea, VT 05038

The Nature and Properties of Soils by Nyle C. Brady and Ray R. Weil. Prentice-Hall Inc., Upper Saddle River, New Jersey07458

Managing Cover Crops Profitably edited by Rodale Institute. Cover Crops Handbook, Sustainable Agriculture Publications -USDA, 342 Aerospace Center, Washington, DC 20250-2200.



Fundamentals of Soil Science RecitationProblem Set 7: Soil Pollution Prevention

Bring your questions on your problem set calculations to recitation. <Answers>to see the work

1. You have been hired by the State of Vermont to determine how much sewage sludge can be disposed of on a 3acre site in Passumpsic, Vermont. The soil's texture is a silt loam. The State of Vermont Regulations allow thefollowing metal loading rates on agricultural land:________________________________________________________________

Metal Loamy Sand,or Sandy Loam

Fine Sandy Loam,Loam, or SiltLoam

Clay Loam, SiltyClay, or Clay

(lbs./acre) Lead 178 356 712 Zinc 250 500 1000 Copper 125 250 500 Nickel 50 100 200 Cadmium 5 10 20 Mercury 5 10 20 Chromium 125 250 500

_________________________________________________________________

The St. Johnsbury sewage sludge has the following analysis:

Lead 400 ppm Zinc 737 ppm Copper 623 ppm Nickel 77 ppm Cadmium 10 ppm Mercury 16 ppm Chromium 342 ppm

a. Please determine the total amount of sewage sludge allowed to be land applied on this site over its entirelifetime. Base your calculation on the heavy metal content limiting application rates.

________________tons over the 3 acre site for its lifetime <601.8>

b. Which of the above metals limits the application of sewage sludge on this site? _______________<copper, Cu>

c. If the amount of sludge from answer a was applied to the top 6 inches of soil, and all the cadmium were toremain uniformly spread throughout the top 6 inches of each acre, what would the concentration of cadmium be? _______________lbs/ton of soil <0.004> _______________% Cd <0.0002>

d. Sewage sludge is applied to farm land in Vermont so crops can use the nutrients. Clean sewage sludge is avaluable resource. Sewage sludge cannot be applied to crops for human consumption, so often it is applied tosilage corn for dairy cows. Activated sewage sludge has a fertilizer analysis of 4-4-1. Silage corn grown on this

prob_set7


fairly fertile siltloam soil with a target yield of 25 tons of fodder/A needs 200 lbs N, 50 lbs P2O5, and 140 lbs ofK2O per acre.

Applications of St. Johnsbury's sewage sludge are limited by the metals for the lifetime of the site. How manyyears can you use the sewage sludge to supply nutrients to the silage corn before metals limit further application?

If you determine your application rates based on supplying enough N for silage corn is the farmer adding enoughP2O5 and K2O or will supplemental amounts of P2O5 and K2O have to be added? For year one, please show howmuch N, P2O5, and K2O have been applied from the sewage sludge, and how much more is needed.

_________ years of sludge applications <80>

Amount Recommended Amount Applied Amount Still NeededN 200 <200> <0>P2O5 50 <200> <150 extra>

K2O 140 <50> <90 needed>

Is this extra phosphorus a problem? Explain why or why not.

prob_set7


Fundamentals of Soil Science RecitationProblem Set 7: Soil Pollution Prevention

Bring your questions on your problem set calculations to recitation.

1. You have been hired by the State of Vermont to determine how much sewage sludge can be disposed of on a 3acre site in Passumpsic, Vermont. The soil's texture is a silt loam. The State of Vermont Regulations allow thefollowing metal loading rates on agricultural land:________________________________________________________________

Metal Loamy Sand,or Sandy Loam

Fine Sandy Loam,Loam, or SiltLoam

Clay Loam, SiltyClay, or Clay

(lbs./acre) Lead 178 356 712 Zinc 250 500 1000 Copper 125 250 500 Nickel 50 100 200 Cadmium 5 10 20 Mercury 5 10 20 Chromium 125 250 500

_________________________________________________________________The St. Johnsbury sewage sludge has the following analysis:

Lead 400 ppm Zinc 737 ppm Copper 623 ppm Nickel 77 ppm Cadmium 10 ppm Mercury 16 ppm Chromium 342 ppm

a. Please determine the total amount of sewage sludge allowed to be land applied on this site over its entirelifetime. Base your calculation on the heavy metal content limiting application rates.<601.8 tons>Let's first figure out how many pounds of metal per ton there are in the sludge. Then we can calculate themaximum tonage that can be applied.

From the table above we know that the sludge has 400 ppm of Pb.We also know that 1 ppm (one part per million) = 1mg/1,000,000mg = 1 mg/1 kg, so

400mg Pb x 1kg x 2000# x 1# x 1g = 0.7999999 = 0.8 # Pb/ton sludge1kg sludge 2.2046 # 1 ton 453.6 g 100mg

If we do the same thing for the rest of the metals

metal metal ppm fromsludge test # of metal/ton

max metalallowed,#/acre

Max sludgeappliedton/A

Lead 400 ppm 0.8 356 445 Zinc 737 ppm 1.474 500 339.2 Copper 623 ppm 1.246 250 200.6

prob_set7


Nickel 77 ppm 0.154 100 649.4 Cadmium 10 ppm 0.02 10 500 Mercury 16 ppm 0.032 10 312.5 Chromium 342 ppm 0.684 250 365.5

Now that we know how many #/ton and the max of metal/acre, we can cross multiply to find the maximumnumber of tons that can be applied for each metal.

1 ton = X tons sludge X=445 tons/A over lifetime of site for Pb, 0.8# Pb 356# total Pb

the same is done for the rest of the metals. From the table above the lowest application rate is the limitingfactor. In this case that number is 200.6 tons per acre for Cu, so no more than 200.6 tons of sludge peracre can be applied to meet state reg's. Or over the whole site: 601.8 tons over the 3 acre site for itslifetime.

b. Which of the above metals limits the application of sewage sludge on this site?<copper, Cu>

c. If the amount of sludge from answer a was applied to the top 6 inches of soil, and all the cadmium were toremain uniformly spread throughout the top 6 inches of each acre, what would the concentration of cadmium be? _______________lbs/ton of soil <0.004> _______________% Cd <0.0002>OK, let's assume that the maximum allowable tonage of sludge was applied (200.6 tons/A).

0.02 # Cd x 200.6 tons sludge applied = 4.0 # Cd/A.f.s.1 ton of sludge A.f.s.

4.0 # x 1 A x 2,000 # = 0.004012 lbs Cd A 2,000,000 # 1 ton soil ton of soil

0.004012 # Cd x 100% = 0.0002% Cd 2000# soil

d. Sewage sludge is applied to farm land in Vermont so crops can use the nutrients. Clean sewage sludge is avaluable resource. Sewage sludge cannot be applied to crops for human consumption, so often it is applied tosilage corn for dairy cows. Activated sewage sludge has a fertilizer analysis of 4-4-1. Silage corn grown on thisfairly fertile siltloam soil with a target yield of 25 tons of fodder/A needs 200 lbs N, 50 lbs P2O5, and 140 lbs ofK2O per acre.

Applications of St. Johnsbury's sewage sludge are limited by the metals for the lifetime of the site. How manyyears can you use the sewage sludge to supply nutrients to the silage corn before metals limit further application?200.6 tons/A is the max allowable lifetime limit.Sludge supplies 4-4-1 and we need 200-50-140, using N as the limiting application factor

100# sludge = X# sludge/A 4# N 200# N

X = 5000 # sludge/A.f.s. or 2.5 tons of sludge/A

(200.6 tons/A)/(2.5 ton/year) = 80.24 years

If you determine your application rates based on supplying enough N for silage corn is the farmer adding enoughP2O5 and K2O or will supplemental amounts of P2O5 and K2O have to be added? For year one, please show how

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much N, P2O5, and K2O have been applied from the sewage sludge, and how much more is needed.

Amount Recommended Amount Applied Amount Still NeededN 200 <200> <0>P2O5 50 <200> <150 extra>

K2O 140 <50> <90 needed>

If we use 5000#/A of sludge we will be applying 5000# x 4%= 5000 x 0.04 = 200 # P2O5, we need only 50 #,so there are 150 #/A too muchand 5000 # x 1% = 5000 x 0.01 = 50 # K2O, we need 140 # or 140-50= 90 more pounds.

Is this extra phosphorus a problem? Explain why or why not.

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Fundamentals of Soil Science RecitationCritical Thinking Exercise 1: Solving Soils Problems

In Prep for Class:

Read through this exercise and the problems on the back. Spend some time thinking about answers to thefirst three brainstorming questions. You may want to spend some time digging for the pieces of the answersin your text book and notes. The comprehensive portion of your final exam will have problems simular toExercise 2.

We will do some exercises in small groups if we have time during the help session for the final exam. Ourfirst priority is to answer all questions on the final exam material. If we don't have time to cover these inclass, try them at home to help you prepare for the final.

A Model for Solving Problems in a Group or Individually:

Solving problems is a part of everyday life and an important part of the relevance of science. Science is atool to help solve problems. It also can create problems if we do not examine its solutions in the context ofour culture and society. I created this exercise to help you develop your problem solving and criticalthinking skills. Problems exercise your brain.

As a Group Exercise:

Prep: Choose one person to facilitate the discussion, one person to take notes and one person to keep time.(All jobs should rotate so everyone get experience doing each task for your group.)

As a group agree to a set period of time to brainstorm and examine your ideas with a critical eye. Allow forsome flexibility, because you may want to revisit a question or idea.

Ask each of the following questions by brainstorming in your group. This means you throw out ideaswithout discussion or judgement of them. After you brain storm a question then discuss each idea with acritical eye. You may want to go back to an earlier question and brainstorm again.

Use this same process to solve problems by yourself.

Remember: Revisit every assumption!

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http://pss.uvm.edu/pss161/problem/prob_ct1.html (1 of 3) [14/07/2001 09:22:00 a.m.]

Brainstorming Questions:

What is the question or problem we are trying to solve?

What do we already know?

What do we need to know?

From who, what, or where could you get this information?

As a group design a plan to guide you in solving each problem. Remember your plan is a guide it should beflexible and be able to change as additional information is acquired. The point is to develop the process thatallows you to reach your goal, which is to determine the best answer for these problems.

Other Questions you may want to ask yourselves during this process:

Where does different information lead us?

Do we have enough information?

Is our information reliable?

What actually is the problem we are trying to solve?

What is an adequate or good solution to this problem?

Good or adequate as defined by who?

Who or what will our solution effect and what will that effect be?

Why is this the best solution (or plan)?

Some Elementary Problems for You to Try to Solve:

1. As you walk from the base of the Green Mountains up across the slope until you reach the summit ofCamel's Hump, what changes will you expect to find because of climate (temperature and rainfall),vegetation (deciduous vs. spruce forest) and topography. Parent material (mica schists) and time (sinceglaciation) are constant. What soil orders might you find along the way?

2. Look at the following data and answer the question.

Soil: A B Texture: silt loam sandy loam % OM: 7.2 % 4.6 % Drainage: Somewhat poorly drained Somewhat poorly drained Land use: Continuous corn Continuous corn

Based on the data above circle which soil you would consider to have the best tilth for growing plants.

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Which would have the best environment for growing plants? Provide an explanation that will supportyour answer.

3. You have been hired to revitalize a poorly managed (in terms of soil) conventional farm. The farm's soilhas poor structure, low organic matter, and this highly eroded soil drains into a wetland. What kind ofproblems might exist in the wetland? Please include crops you might grow, tillage systems, fertilizers, etc.

4. The following site was flood by a hydro-electric project. Please describe the chemical and biologicalenvironment. Would phosphorous be more or less available under the flooded condition?

Site: sandy loam, pH 4.7, Coniferous vegetation recently removed.

5. You had a soil test done and your loamy textured soil has a pH of 4.0 (very acidic). So you go buy a newliming material which is a mixture of dolomitic limestone and woodashes (KCO3), and add the requiredamount to bring the pH to 6.0. Describe the biological (what macro and micro organism are present) and thechemical (which cations are present and where) environments that exist before liming and 6-12 months laterwhen after the limestone has reacted and brought the pH up to 6.0. How will the soils Physical properties beeffected?

6. Develop an agriculture system that is sustainable in a semi- tropical to tropical climate that has highlyweathered soils, lots of rainfall, occasional flooding and occasional very dry or droughty periods?

7. Friends of your's have just purchased and remodeled an old hunting camp in the Green Mountains ofVermont. They cleared away maple, beech, white pine trees to provide space for a vegetable and flowergarden. The soil survey says this till soil is rocky, infertile, acid, and sandy. It also can be wet in springbecause of the dense basil till layer. Your friends want to know how to create a fertile garden this year.What would you recommend they do and in what order should they do it?

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Fundamentals of Soil Science RecitationCritical Thinking Exercise 2: Solving Soils Problems

Use your problem solving skills you developed in Exercise 1 on these problems. Before class readthrough the problems below, think about them, jot down your ideas, and you may want to do somepreliminary research in you book and course notes. Please note these problems are more complex thanthe first exercise and thus, require more complexity in the answers. The comprehensive portion of yourfinal exam will have problems similar to these.

Set A.

1. Well, you know what the economy's like. So after you graduated you decided to go into the PeaceCorp and have ended up in a small town in Africa near the shifting sands of the Sahara Desert. Resourcesare very tight. Your mission is use your knowledge to help the people develop an agroecosystem thatintegrates humans and their environment. Please outline how you would approach this problem. Alsoplease specifically tell us what you have learned from PSS 161 that could use to help solve this problem.

2. The Moon's crust is potassium rich. It also contains phosphorus, iron, magnesium, calcium, silica,barium, as well as other metals because of its feldspar and basalt bedrock. What the crust does notcontain is any sodium, carbon, nitrogen, organic matter, and microbes or other forms of life. The surfacecontains dust and breccia, rocks composed of angular fragments melted together during the impact ofspace debris. You have been hired to develop agriculture on the Moon that will support a space colonystationed there to service space vessels coming to and leaving from Earth. You have 10 acres and all thewater supply you need. Please outline how you would develop a sustainable agricultural system for themoon.

3. The US Office of Produce Site Inspection (US-OOPSI) was set up 5 years ago after the passage ofGATT to inspect and test produce coming into the US for pesticide residues in order to determinecontamination levels. Shipments of rejected produce is barred from entering the US and sent back to thecountry of its origin. However, the remains of the produce tested is disposed of in landfills in the US.Thousands of pieces of produce are tested daily. This contaminated "garbage" produce has high levels ofmany different types of pesticides, including DDT and other pesticides restricted in the US. Landfillingthese contaminated wastes is expensive. Please describe and alternative waste management/treatmentscheme that allows OOPSI to safely utilize\dispose of this contaminated waste.

4. Now that the country of Russia has opened its economic doors to the USA, it is also asking us for helpwith its environmental problems. You have been hired to design and carry out an ecological restorationof the area surrounding their hugh smelter situated near the arctic circle. This smelter has no air pollutioncontrols and releases tremendous amounts of heavy metals (Ni, Cu, Cd, Zn), particulates (soot), and SO2into the atmosphere. It has created a haze in this region's atmosphere that has been spread around theglobe. An area of vegetation and soil 25 square miles has been affected by the fall out. As you get closeto the smoke plume of the smelter living vegetation peters out. Please describe the steps you would taketo restore this site, keeping in mind that the US tax payer is footing the bill.

Set B.

1. You are a Peace Corp volunteer in southwestern India that has been put in charge of a land reclamationprogram. The area has a tropical climate with a dry rainless season and a wet monsoon season. The soils

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are steep, highly weathered oxisols which have been eroded to the cemented lateritic layer. How will youreclaim this land for agricultural use in this climate given that the people are very poor, have nomechanization, are in great need of food and fuel, and you have scarce resources to work with?

2. You have been hired to help with the land application of wastes from a french fry processing plant inIdaho. The waste has a pH of 8.0. It is high sodium chloride (NaCl). It also is very high in organicmaterials, like starch, and thus has a high biological oxygen demand (BOD). Therefore, this waste mustbe disposed of on soil. The soils available in this semi-arid climate are mollisols (prairie soils) which areunder grasses, have a thick dark surface layer, a high base saturation, and high amounts of CaCO3 in theprofile with a pH of 7.5. What problems might you encounter from land application of this material?What solutions can you suggest?

3. The State of Vermont has hired you to design and carry out a ecological restoration of the BurlingtonBarge Canal (an EPA super fund site) which was a marshy area before it was filled with coal tar wastesand fill materials. Total affected are less than 5 acres. The coal tar waste is relatively inactive, but somecompounds may be mobile. Outline your proposed solutions.

4. You have been hired to help establish plants on material dredge from the harbor in Baltimore, MD.This material is extremely acidic, contains organic material, and is high in clays. It also contains highlevels of some pollutants that have gotten into the harbor: mercury, zinc and various other heavy metals.What practices and considerations will you make in trying to reclaim this site and establish vegetation?

Set C.

1. The people of Somalia are in crisis. If you were sent to Somalia tomorrow as part of a team who wouldhelp design an agroecological system in this drought stricken country to prevent mass starvation in thefuture, what practices or policies would you recommend as the foundation of this agroecological system?

2. It is the year 2042, the earth has been depleted of petroleum supplies and the increases in populationhas caused former industrialize counties to reclaim the space along roads for agriculture. What hazardsmust be addressed in doing this? What solutions do you suggest?

3. As depletion of the ozone layer continues, scientists are predicting that an ozone hole will show upover the Arctic and North America. An ozone reduction would expose the earth's surface to moreultraviolet radiation. What effect would you predict this might have on agricultural soils in the northernU.S. (like Vermont) that are often fallow in the winter?

4. NASA's Biospheric Sciences Branch has hired you to design and carry out a ecological restoration for250,000 acres of burned, farmed, and eroded land on the edge of Brasil's Amazon Forest. These acreswere purchased in Clinton's Debt for Diversity foreign aid program. The Republican Congress hasslashed your merge funding, so you're on a shoe-string budget. They have asked you to outline yourproposal.

Set D.

1. You have been hired as an international agroecological consultant by the Association of Israel andPalestinian Agriculturalists (AIPA) to develop an agriculture plan to support the expected population

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shifts to the West Bank and Gaza Strip after the signing of the Peace Agreement. Please outline thefundamental points of your plan to design an sustainable agricultural system from the bottom up in thisdesert region. (There are considerable resources available from the USA to help you do it right.)

2. You have been hired as the environmental scientist on a consulting team that is going to detoxify land,so it is fit for human habitation, within a 20 mile radius of the melted down and entombed reactor core ofthe Chernobyl nuclear power plant. The soil is contaminated with radioactive metals. Develop a plan thatcovers different possible solutions to this problem.

3. The McGill paper company in your hometown has been applying their paper mill sludges toagricultural land for the past 30 years. The paper mill sludges are valued by vegetable growers as atremendous source of carbon to build organic matter. Recent testing of the sludges has shown high levelsof dioxin. Dioxin is a carcinogenic chlorinated carbon compound, which forms during the paper makingprocess when the paper is bleached with chlorine. Soil tests from sludged land also have shownabnormally high levels of dioxin. Steps must be taken immediate to deal with this problem. What do yourecommend?

4. Since the signing of the USA-Russia Allies Agreement and the official end of the cold war the USAhas declassified and abandon many of its military bases. You have been hired to design and establishnative vegetation that can ultimately maintain itself. Your first site is an old landing strip in a pine barrencoastal area of New Jersey. Topsoil was removed before the sandy area was compacted and covered withasphalt. How would you prepare the site for revegetation of pitch pines and scrub oak, which are thenative vegetation to this fire prone area?

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pss 161 fundamentals of soil...

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