Cca

Front 1

NH4

Back 1

Ammonium, solid

Front 2

NH3

Back 2

Anhydrous Ammonia (gas at reduced pressure, liquid under pressure) not plant available, 82-0-0,

Front 3

NO2

Back 3

Nitrite (unavailable to plant)

Front 4

NO3

Back 4

Nitrate (leached out or denitrified)

Front 5

NH2(2CO)

Back 5

Urea, 46-0-0, solid

Front 6

UAN

Back 6

Urea plus ammonium Nitrate solution- 28-0-0 to 32-0-0, liquid

Front 7

NH4NO3

Back 7

Ammonium Nitrate, 33.5-0-0 or 34.0-0-0 solid

Front 8

(NH4)2SO4

Back 8

Ammonium Sulfate, 21-0-0, solid

Front 9

Which Phosphorus form is a liquid?

Back 9

Ammonium Polyphosphate, 10-34-0 to 11-37-0

Front 10

%P = _ x %P2O5

Back 10

0.44 reverse is 2.29

Front 11

%K= _ x %K2O

Back 11

.83 reverse is 1.21

Front 12

Potassium Forms are all Solid or Liquid?

Back 12

Solid

Front 13

T or F A fertile soil is always a productive soil?

Back 13

False

Front 14

What are 6 external factors that control plant growth?

Back 14

Air, temperature, light, water, mechanical support, & nutrients

Front 15

How many essential plant chemical elements are there and how many are found in the soil?

Back 15

17 total and 14 in the Soil

Front 16

When is a nutrient considered to be essential?

Back 16

If it is necessary for the plant to complete its life cycle & no other element can substitute for it completely.

Front 17

What essential nutrients are non mineral?

Back 17

Carbon, hydrogen, Oxygen. Found in the atmosphere and water.

Front 18

How many micronutrients are there?

Back 18

6 N,P,K,Ca,Mg,S

Front 19

How many micronutrients are there?

Back 19

8 B,Cl,Cu,Fe,Mn,Mo,Ni,Zn

Front 20

What are the four additional nutrients that are almost never deficient in Soils?

Back 20

Sodium Na, Cobalt Co, Vanadium V, Silicon Si

Front 21

T or F, Nitrogen, P & S are all micronutrients?

Back 21

True

Front 22

T or F, Macronutrients are more essential than micronutrients?

Back 22

False

Front 23

When is a soil texture classified as loamy sand or sandy loam?

Back 23

When small amounts of silt or clay are present

Front 24

How many soil textural classes are there?

Back 24

12

Front 25

When is soil classified as a clay loam?

Back 25

When sand, silt, and clay are all present in similar proportions.

Front 26

What are the structural types of soil?

Back 26

Blocky, granular, and prismatic

Front 27

Which particle size has a higher surface area, large or small?

Back 27

Smaller particle sizes. As surface area increases water absorbed (held) increases

Front 28

What soil texture holds the largest amount of plant avaliable water?

Back 28

Silt loam

Front 29

What is the best structure soil for ease of crop management?

Back 29

Blocky or granular

Front 30

What is the most difficult soil structure?

Back 30

Soils high in silt, easily compacted

Front 31

T or F, sandy Soils have finer textures than clay Soils?

Back 31

False

Front 32

Which soil has larger pore spaces, clay or sand?

Back 32

Sand

Front 33

The water a plant uses for its growth is called?

Back 33

Available water

Front 34

What is the ideal soil for crop production?

Back 34

Medium textured (loamy), adequate clay content to retain sufficient soil moisture, deep permeable sub soil, suitable environment for roots to go deep, minimal compaction, acidity, or salinity

Front 35

Colloids

Back 35

Very small particles not seen by the naked eye. Most mineral clay colloids are plate like in structure. Most Soils contain more clay colloids than organic colloids.

Front 36

What is a colloid primarily responsible for?

Back 36

The chemical reactivity in soils

Front 37

What charge is a clay colloid?

Back 37

Net negative charge. Organic colloids are also net negative but their negative charge decreases as the soil ph declines (variable charge).

Front 38

% of clay in loamy sand

Back 38

5

Front 39

% of clay in sandy loam

Back 39

10

Front 40

% of clay in silt loam

Back 40

20

Front 41

% of clay in silt clay loam

Back 41

30

Front 42

% of clay in clay loam

Back 42

35

Front 43

% of clay in clay

Back 43

>40

Front 44

What does the CEC depend on?

Back 44

Amounts and kinds of clay and the amount of organic matter present.

Front 45

What is the CEC expressed as?

Back 45

Centimoles of charge per kilogram of soil (cmol/kg) also milliequivalents per 100 grams soil (meq/100g). Both are equal

Front 46

What is the CEC of clay minerals?

Back 46

200-400 cmol/kg

Front 47

What is the CEC of organic matter?

Back 47

200-400 cmol/kg

Front 48

Cations

Back 48

Potassium, sodium, hydrogen, calcium, magnesium

Front 49

Potassium ionic form

Back 49

K+

Front 50

Sodium ionic form

Back 50

Na+

Front 51

Hydrogen ionic form

Back 51

H+

Front 52

Calcium ionic form

Back 52

Ca2+

Front 53

Magnesium ionic form

Back 53

Mg2+

Front 54

Anions

Back 54

Chloride, Nitrate, sulfate, phosphate

Front 55

Chloride ionic form

Back 55

Cl-

Front 56

Nitrate ionic form

Back 56

NO3-

Front 57

Sulfate ionic form

Back 57

SO2-

Front 58

Phosphate ionic form

Back 58

HPO42 ; H2PO4-

Front 59

What does cation exchange capacity depend on?

Back 59

Amounts and kinds of clay and the amount of organic matter present. The total number of exchangeable cations a soil can hold (the amount of its negative charge)

Front 60

How does the cec increase?

Back 60

As the OM content increases

Front 61

What is cec expressed in?

Back 61

Centimoles of charge per kilogram of soil (cmol/kg) and also milliequivalents per 100 grams of soil (meq/100 g).

Both are equal!

Front 62

What is the cec of clay minerals usually?

Back 62

10- 150 cmol/kg

Front 63

What is the cec of organic matter?

Back 63

200-400 cmol/kg

Front 64

What helps reduce the potential of Nitrate NO3- leaching?

Back 64

Splitting N applications using nitrification inhibitors and timing applications to meet peak crop demands.

Front 65

What has been used to develop fertilizer programs?

Back 65

Base saturation- the percent of the total CEC occupied by the exchangeable basic cations (calcium, magnesium, potassium, sodium)

The concept is that a certain ideal cation ratio or balance is needed to assure optimum yields.

Front 66

Is Nitrate mobile in the soil?

Back 66

Nitrate is highly mobile and moves freely with soil mositure. Under high rainfall it moves downward. Under extremely dry weather it may move upward with soul mositure causing NO3- to accumulate on the surface.

Front 67

Can sulfate attract to OM at low PH?

Back 67

Yes organic matter sometimes develops a positive charge at low ph and sulfate SO42- can be attracted to it.

Front 68

Is phosphate mobile in soil?

Back 68

Immobile in the soil because of adsorption and precipitation reactions with the soil minerals. Held strongly by the soil through various chemical reactions.

Front 69

What charge is sand?

Back 69

Carry little or no charge and do not react with CEC.

Front 70

50 cec is classified as?

Back 70

Heavy clay! 0= sand

Front 71

Does a higher or lower CEC soil require more lime?

Back 71

Higher cec requires more lime because it contains more acidity, more anions then the lower cec soil

Front 72

How much nitrogen does OM contain

Back 72

5%. Serves as a storehouse for plant avaliable N. Not immediately avaiable to the plant, must decompose completely

Front 73

How many tons per acre of residues in high yielding corn is left after harvest?

Back 73

8 tons per acre

Front 74

Are soil OM levels usually higher is warmer climates with higher rainfall?

Back 74

False

Front 75

What is soil aggregation?

Back 75

The resistance of soil particles being able to break apart.

Front 76

What is an acid?

Back 76

A substance that releases hydrogen ions (H+), saturated with H+ the soil behaves as a weak acidic, the more H+ held in the cec the greater the Soils acidity.

Front 77

Hydrogen ion + in soil/cec

Back 77

Cation exchange can increase alkalinity whenever hydrogen ions in solution exchange on surfaces for base cations. The effect is generally reversible, and thus the process may not contribute to long-term increases in alkalinity once the cation exchange sites are depleted. In fact, cation exchange can act in reverse if base cations are added from sea spray or road salt to a soil solution, causing temporary acidification and loss of alkalinity. Nevertheless, soils with large cation exchange capacities can act as a large buffering reserve against relatively short-term acidification events.

Front 78

How does decomposition affect soil ph?

Back 78

Soil OM is continuously being decomposed by microorganisms into acids.

Front 79

How does rainfall affect PH?

Back 79

Rainfall passes through the soil, basic nutrients like Ca and Mg are leached below the root zone. They are replaced by acidic elements like Al, H, and Mnthat are more acidic.

Front 80

How does nitrogen fertilization affect PH

Back 80

Speeds up the rate of which acidity develops unless the nitrogen is supplied in the form of Nitrate (NO3).

Front 81

What are the base cations.

Back 81

Ammonium, magnesium, potassium, calcium, sodium

Front 82

What are the acidic cations?

Back 82

Hydrogen & aluminum

Front 83

Do legumes usually contain more Ca & Mg than non legumes.

Back 83

Yes

Front 84

Some nitrogen fertilizers can produce acidity in the soil?

Back 84

True

Front 85

Lime requirement is related to both?

Back 85

PH and Cation Exchange capacity

Front 86

Buffer capacity

Back 86

The measure of a Soils resistance to PH change.

Front 87

Buffering capacities are higher for sands than clays?

Back 87

False, buffering is higher when clay and OM are present.

Front 88

A general lime requirement can be determined properly only if what is measured?

Back 88

Potential acidity

Front 89

For best results, when is lime applied?

Back 89

Several months before planting to allow sufficient time to neutralize soil acidity. Or after harvest if already planted.

Front 90

Solubilitied of ion such as Al and Mn increase as soil PH increases to potentially toxic levels.

Back 90

True

Front 91

Low soil PH does not affect symbiotic nitrogen fixation by legumes?

Back 91

False, greatly reduced

Front 92

Which crop grows best in ph range above 6.5, corn, alfalfa, wheat, soybeans, watermelon?

Back 92

Alfalfa

Front 93

What should be considered in a soil ph maintenance and lime program?

Back 93

Lime cost, specific soil, micronutrient levels. Soil mineralogy, the potential for Al toxicity. Soil phosphorus levels. Whether sub soil PH is higher or lower than in the surface soil. Soil tillage system, specific disease risks

Front 94

What do liming materials remove from the soil?

Back 94

H+ and aluminum (Al3+)

Front 95

Liming increases soil ph but converting H+ into....?

Back 95

Water and Soluble aluminum (Al3+) into insoluble Al(OH)3

Front 96

Which soil needs to be limed more Sandy or Clay?

Back 96

Sandy Soils

Front 97

Basic slack has a higher neutralizing value than CaCO3 (calcitic lime)?

Back 97

False

Front 98

Do oxides or carbonates react more rapidly?

Back 98

Oxides

Front 99

Calcium lime (CaO) is also called?

Back 99

Unslacked lime, burned lime, or quicklime

Front 100

What do the neutralizing values of lime usually range from?

Back 100

65-70% to more than 100%

Front 101

Can acidic soil cut fertilizer efficiency as much as 50%?

Back 101

Yes by damaging roots and stunting growth.

Front 102

Which soil contains free calcium carbonate? CaCO3

Back 102

Calcareous

Front 103

How is the degree of salinity measured on the soil testing lab?

Back 103

As electrical conductivity

Front 104

What crops are salt tolerant?

Back 104

Barley, cotton, sugar beets, canola, bermudagrass, sweet clover

Front 105

Sodium (alkali) contain higher amounts of?

Back 105

Sodium

Front 106

Is gypsum used to reclaim sodic Soils?

Back 106

True

Front 107

Sodic Alkali soil

Back 107

Excessive amounts of salts and ph above 8.5

Front 108

Saline Soils

Back 108

Excessive sodium and ph less then 8.4 or less

Front 109

Is Sulfur need closely related to the amount of Nitrogen available to crop plants?

Back 109

True

Front 110

Is sulfur mobile in plants?

Back 110

No

Front 111

Most plants contain about the same amount of Mg to S & S to P?

Back 111

True

Front 112

Is Sulfur considered the 4th most needed fertilizer after NPK?

Back 112

Yes

Front 113

How is Sulfur absorbed in plants?

Back 113

As the sulfate (SO42-) anion. It can also enter plant leaves from the air as Sulfur dioxide (SO2) gas, and so crops are rarely deficient in S in areas of industrial air pollution

Front 114

Is Sulfur required for Protein Synthesis?

Back 114

Yes, it aids in seed production and producing the chlorophyll necessary for plants to carry out photosynthesis.

Front 115

What are the three S containing amino acids?

Back 115

Cysteine, methionine, and cystine

Front 116

What is S required for in legume crops?

Back 116

Nodule formation on root hairs

Front 117

What happens if you have a shortage of S?

Back 117

Reduces crop yield & quality. Bread baked with low S wheat will not rise properly and has dense loves because certain proteins are missing in the grain.

Front 118

Are N & S both needed for protein formation?

Back 118

Yes, S availability can't be ignored when evaluating N fertilizer use efficiency.

Front 119

Is sulfate an Anion or cation?

Back 119

Anion

Front 120

Most S found in Soils is contained in?

Back 120

OM

Front 121

Why does Sulfur remain in soil soultion and move with soil water?

Back 121

Because it is an anion and is not attracted to most clay soils and OM surfaces. It is readily leached because of this.

Front 122

Where is much of Sulfur store?

Back 122

In soil OM

Front 123

Leaching of sulfate SO42-

Is more likely is what textured soil vs another?

Back 123

Coarser textured Soils than finer textured soils

Front 124

What % of S is contained in fertilizer forms of elemental S?

Back 124

85%

Front 125

What fertilizer material contains the most Sulfur?

Back 125

Ammonium polysulfide 40-50%

Front 126

What is gypsum?

Back 126

Calcium Sulfate

Front 127

Fertilizers that contain insoluble elemental S require a conversion to Sulfate before plants can take it up.

Back 127

Yes, S+water+oxygen = sulfuric acid (H2SO4)

Front 128

Sulfates are water solvable while elemental S is water insoluble.

Back 128

True

Front 129

Extremely small particles of elemental S fertilizer are called?

Back 129

Micronized- S converts to SO42 (Sulfate) in the soil quickly. Currently applied as a fungicide.

Front 130

Plants can utilize elemental S?

Back 130

False

Front 131

Is Sulfur mobile in the plant?

Back 131

False

Front 132

What crops have a high Sulfur requirement?

Back 132

Oilseeds like soybean and canola, ans forage crops

Front 133

How is calcium taken up by plants?

Back 133

Ca2+ cation

Front 134

Roles of calcium in plants?

Back 134

Stimulates root and lead development, forms compounds of cell wall to strength plant structure, helps reduce Nitrate- N (NO3-_N) in plant, lowers toxicity of Mn & Al,

Front 135

Do clay Soils usually contain more calcium than sandy Soils?

Back 135

Yes more Cec capabilities in clay

Front 136

Calcium deficiencies are commonly seen on older plants tissue?

Back 136

False- Calcium has low mobility in plants so it will affect the younger tissue first

Front 137

Does calcium move with the transportation of water?

Back 137

Yes, sometimes deficiencies appear on plant parts that have little water loss.

Front 138

How is Mg taken up by plants?

Back 138

As the Mg2+ cation.

Front 139

Mg & N are the only soil nutrients that are constituents of Chlorophyll?

Back 139

True

Front 140

Mg is not absorbed as tightly by clay and OM so is more susceptible to leaching?

Back 140

True

Front 141

Magnesium is usually most deficient in Coarse textured Soils under high rain fall conditions?

Back 141

True

Front 142

Magnesium deficiency usually appear on younger or older leaves first?

Back 142

Older, Mg is mobile in plants and when a deficiency occurs, chlorophyll in the older leaves is broken down and transported to the new plant growth.

Front 143

What are the 8 essential micronutrients?

Back 143

Boron, chloride, copper, Manganese, molybdenum, nickel, zinc, iron

Front 144

The availability of most micronutrients in the soil increases as soil ph increases?

Back 144

False

Front 145

What is a crops nutrient requirement supplied by?

Back 145

Soil and fertilizer

Front 146

Fertilizer needs can be reliably determined based on crop removal alone?

Back 146

False, doesn't take into affect the soil nutrients.

Front 147

Soil testing is a helpful management tool for immobile nutrients even in areas with wide weather induced variations?

Back 147

True

Front 148

Soil testing is the single best management tool for mobile nutrients even in areas with wide weather induced variations?

Back 148

False, nutrient sufficiency & build maintenance

Front 149

The sufficiency approach is more likely to maximize profits in the year of application and the build maintenance approach is more likely to maximize yields?

Back 149

True

Front 150

The goal of the sufficiency approach is to raise the soil test to a level sufficient for maximum yields?

Back 150

False it is to use just enough fertilizer to maximize profitability in the year of application.

Front 151

The presidedress Nitrate test or late spring Nitrate test has been proposed as an early indicator of yield potential?

Back 151

False- it has been correlated with N response in maize.

Front 152

What does NDVI stand for?

Back 152

Normalized difference vegetation index

Front 153

What are indirect methods for sampling?

Back 153

Leaf color chart, chlorophyll meter, optical sensors, drones

Front 154

Is purchasing nitrogen a long term or short term investment?

Back 154

Short term because it does stay in the soil due to leaching or volitalization

Front 155

Is purchasing P&K fertilizer a short term or long term investment?

Back 155

Long term because it stay in the soil for the next crop usually.

Front 156

Early planting and K fertilization of corn interact positively to increase yield potential?

Back 156

True

Front 157

What does MEY stand for?

Back 157

Maximum economic yield

Front 158

MEY definition

Back 158

That yield where unit costs are lowered to the point of highest net return per acre- the most profitable yield.

Front 159

When does it become unprofitable to increase fertilizer rates?

Back 159

At the point of maximum profit (diminishing returns). The key to additional fertilizer increments is whether the return was greater than the cost. You may have a higher yield then last crop but a lower net return overall

Front 160

The key to deciding whether to use additional fertilizer increments is whether or not the last increment produced a return as high as the previous one?

Back 160

True, more input can cause a higher yields but a lower return on $ due to input

Front 161

What is variable rate fertilizer application?

Back 161

Variable rate fertilizer application allows crop producers to apply different rates of fertilizer at each location across fields.

Front 162

From a crops view there is no difference among the various nutrient sources (organic or inorganic)?

Back 162

True because a plant doesn't use nutrients in their original forms. All nutrients must be in a soluble form before they can be taken up by the plant roots.