Exam 3 Flashcards
(202 cards)
1
Q
A dynamic natural body composed of minerals and organic material and living organisms in which plants grow is what?
A
Soil
2
Q
Composition of a soil with 45 degrees is what?
A
minerals
3
Q
Composition of a soil with 5 degrees is what?
A
organic matter
4
Q
Composition of a soil with 25 degrees is what?
A
air
5
Q
Composition of a soil with 25 degrees is what?
A
water
6
Q
Soil develps as a result of the combined effect of? Which acts on? And is influenced by ?
A
climate and organisms
soil
topography over time
7
Q
What is a layer of soil parallel to the surface differing in characteristics from the soil above and below?
A
Soil Horizon
8
Q
Which horizon is the mineral horizon enriched with organic matter?
A
A
9
Q
Which horizon is the less-weathered horizon where materials such as clay accumulate?
A
B
10
Q
Which horizon is unconsolidated parent material; least weathered horizon?
A
C
11
Q
Which horizon is consolidated rock?
A
R
12
Q
Which is horizon is the most important for plant development?
A
A
13
Q
What is the organic horizon?
A
Grass
14
Q
What horizon are most roots found in?
A
A
15
Q
Soil provides plants with?
A
A place to anchor roots
Water
Mineral nutrients
16
Q
Soil tilth-the physical condition of the soil as it relates to?
A
tillage
planting
germination
emergence
17
Q
A soil with good tilth will have adequate? Which holds? and will have an adegquate supply of?
A
pore space
water and air
nutrients
18
Q
What physical condition is texture, structure, soil organic matter, density, and porosity?
A
Tilth
19
Q
Soil tilth is the function of soil?
A
Structure
Texture
Fertility
Organic Matter
20
Q
Maintaining soil tilth requires careful?
It is improved by reducing?
A
Timing of farming operations
Tillage
21
Q
Soil properties that influence soil tilth and crop growth?
A
Texture Structure Soil Organic Matter Density Porosity
22
Q
The relative proportion of various sizes of soil particles is?
A
Soil texture
23
Q
What soil particle size is < .002 mm
A
Clay
24
Q
What soil particle size is 0.002-0.05 mm
A
Silt
25
What soil particle size is 0.05-2.0 mm
Sand
26
Soil Textures are
Clay
Silt
Sand
Loam
27
Is loam considered a soil particle?
NO
28
What is the arrangement of soil particles in to groups called?
Soil structure
29
Soil structure groups are called?
Peds or aggregates
30
Soil structure may be an indicator of soil...
organic matter content or compaction
31
Resembles cookie crumbs and is usually less than .5 cm in diameter. Commonly found in surface horizons where roots have been growing
Granular
32
What horizon are most roots located on?
A horizon
33
What soil structure is thin, flat plates of soil that lie horizontally and are usually found in compacted soil?
Platy
34
Platy have low accumilation of?
water
35
What soil structure is irrgular blocks that are usually 1.5-5.0 cm in diameter and are common in subsoils or C horizon
Blocky
36
What soil structure has vertical columns of soil that might be a number of cm long and are usually found in lower horizons and are very long adn deep within the soril adn are B or C horizons?
Prismatic
37
What soil strucuter has vertical columns of soil that have a salt "cap" at the top and are found in soils of arid climates with dense, low water movement?
Columnar
38
Which soil structure has high organic matter?
Granular
39
The residues of plants, animals, and microorganisms broken down over time is?
Soil organic matter
40
Most soils contain how much organic matter?
1 to 6%
41
Decompostition of living organisms is how much carbon?
45-50%
42
Release of NPK is?
Nutritional
43
Important for living organism is?
Biological
44
Increase water and air capactiy and also improves the porosity is?
Physical
45
What is the porosity?
How many pores are in the soil
46
Functions of soil organic matter?
Contributes to soil tilth
Increases water holding capacity
Releases mineral nutrients for plants
47
What is the mass of soil per unit volume or Dry soil mass/soil volume?
Bulk Density
48
High bulk density makes what difficult?
Root growth and tillage
49
Higher organic matter=
lower bulk density
50
Soils with low porosity have?
Higher bulk density
51
A portion fo a volume of soil that is not occupied by soil particles and are spaces filled with water or air is?
Pore space or Porosity
52
Large pores are called?
Macropores
53
Small pores are called?
Micropores
54
Macropores have roots that?
Penetrate easier here and there is a higher amount of air
55
Micropores is where what is found?
Water
56
Pore space is occupied by?
Either air or water
57
Total pore space is usually what and water content what?
Lower and higher at greater depths
58
Which horizon has a higher porosity?
A
59
The process of exchanging gases between the soil and the atmosphere is what?
Soil aeration
60
What is organisms living in the soil (including plants) use oxygen to produce carbon dioxide in respiration?
Soil aeration
61
Unbalanced aeration can accumulate what?
Toxins
62
The amount of water a soil is able to hold is?
Soil water content
63
Soil water content is determined by?
The number of pore spaces available adn the size of the pores that hold water
64
Soil water content can be measured as?
Weight or volume
65
Water content does not equal water?
Availability
66
The more negative the water potential, the ..... the plant has to work
harder
67
Do soil characterisitcs affect how land is used?
Yes
68
Only about what percent of the earth's surface is arable land?
11
69
Most of the world's utlized arable land is in?
US, Europe, and Asia
70
Soil characteristics and land use can be predicted by knowing?
Soil orders
71
How many soil orders are there?
12
72
Agriculturally important soil orders are?
Mollisol, Alfisol, and Ultisol
73
What soil order is dark coloration formed under grasslands and are very fertile and high in nitrogen?
Mollisol
74
What soil order looks like clay, translocation of clay, and naturally fertil so less fertilization?
Alfisol
75
What soil order has red coloration, humid and warm regions, adn need right management to be reproductive?
Ultisol
76
Reasons for tilling?
Improve soil condition, shape soil, and manage pests
77
Agricultural preperation fo the soil is?
Tillage
78
Prepare seedbeds, controls weeds: eliminates competition, adn improves physical conditions of the soil is?
Tillage
79
Tillage improves?
Seed/soil contact
80
Tillage influences?
Soil structure
Water holding capacity
Drainage
Aeration
81
Tillages shapes the soil by?
Smooth soil surface
| Raise beds
82
Why till?
```
Control weeds,
Only method before herbicides
Bury seeds, rhizomes
Some weeds become more problematic
Reduce disease inoculum
Bury plant residue
Disrupt insect life cycles
```
83
Two types of tillage?
Primary and Secondary
84
Leaves the soil surface rough?
Primay Tillage
85
Moldboard, Chisel, Disk, Sweep
Primary Tillage
86
Follows primary tillage, prepares seedbed, weed control incorporate herbicides adn uproot weeds
Secondary tillage
87
Tandem Disk, Rotary Hoe, Harrow, Bedder, Field cultivator
Secondary Tillage
88
Compare and contrast primary and secondary?
Both used in tillage practices, primary is more economical and secondary is not as economical. Primary leaves the soil rough and secondary is leaves the soil smoother than primary.
89
Involves plowing and or multiple tillage passes
Conventional
90
Leaves less than 15 percent residue cover after planting?
Conventional
91
Advantages of Conventional Tillage?
Excellent Seedbed
Improved aeration
Helps control pests
Levels field for easier harvest
92
Disadvantages of Conventional Tillage?
More trips across field (time, money for fuel)
Compaction (plow pan may form)
Reduced organic matter
Increases potential for soil erosion
Poor water infiltration and no stopping wind and rain
93
More than 30 percent of crop residue remains on soil surface?
Conservational
94
Advantages of conservation tillage?
Reduce erosion by 95%
Better water infiltration increased water use efficiency
Increased amount of land capable of supporting row crops
Increased amount of land managed by one person
Save money on fuel
95
Disadvantages of conservation tillage
```
lower yeilds with cool wet springs
lower yeidls on poorly drained soils
poor distribution of fertilizer
increased problems with certain pests
increased dependence on herbicides
```
96
Zero till, direct seeding or planting
No till
97
Soil is undisturbed
No Till
98
Tillage just for seeding
No till
99
Tillage only for weed control with sweep
Mulch till
100
Soil is disturbed
Mulch till
101
Minimum tillage
Strip till
102
Combining advantages of both conventional and conservation
Strip till
103
Soil is partially disturbed
Strip till
104
Planting occurs on the ridge
Ridge till
105
Formation of ridges 1 year before seeding on ridge
Ridge till
106
Residue remains in between ridges
Ridge till
107
Seedbed
Conventional
108
Pest managment
Conventional
109
Soil organic matter
Conservational
110
Compaction
Conventional
111
Potential Erosion
Conventional
112
Efficiency Managemtn
Conservation
113
Slows water runoff, more efficient and easier on equipment
Contour farming
114
Different than strip till-Alternates grass adn crops, reduce erosion and slows water runoff
Strip Cropping
115
Remove water in excess, keep level moisture down
Drain tile
116
Wide strips of native grasslange
Grassed waterways
117
Variety or hybrid selection consider
Yield, environment, pest resistance, pest management strategy, other desirable traits
118
An indicator of the ability of a seed to develop into a productive plant
Seed quality
119
Seed quality factors
```
Viability
Purity
Vigor
Presence of pathogens, insects, or weed seed
Mechanical damage
```
120
One way to quantify viable seeds is to calculate the
percent germination
121
The ability of a seed to germinate under favorable conditions
viability
122
germinated/total x 100
percent germination
123
Testing viability
Rolled towel, petri dish
124
Tetrazolium test
viability of dormant seeds
125
Potential for rapid emergence of normal seedlings in field conditions
Seed vigor
126
Tests for seed vigor
Cold test and accelerated aging
127
Measures the percentage of the desired seed in teh sample
Seed purity
128
Seed purity must determine
seeds of other crops
weed seeds
inert materials
129
100%-%other crop-%weed-%inert material =purity
seed purity
130
Injurious to health or to the environment cant sell or transport
Prohibited
131
Must be controlled to avoid infestation, only have in small quantities
Restricted
132
Canada thistle, quackgrass
prohibited
133
dodder, giant foxtail
restricted
134
State associations that provide high quality seeds of varieties developed by university breeders
Public seed associations
135
Most common source of agronomic seeds
Private seed companies
136
Lowest quality of seed
Farmer saved seed
137
Farmer saved seed also called
Bin-run or brown bagged
138
Variation of single row, better use of space, more plants per area
Twin row
139
Reduce problems with depth, way to push the seeds, developing countries
hill drop
140
Amount of seeds per area
Seeding rates
141
Potimum seeding rate is important; too low resluts in
wasted resources
142
too high results in seeding rates
intraspecific competition
143
Planting dpth is influenced by
seed size
seed emergence pattern
soil conditions
144
How efficiently plant uses water
Plant water use efficiency
145
WUE=
Dry matter produced/water consumed
146
Total water consumed in teh production of plant biomass
Evapotranspiration
147
Water lost through transpiration by the plant plus water lost through evaporation from the soil?
Evapotranspiration
148
Oldest method of irrigation?
Gravity flow or flood irrigation
149
Flood irrigation is used for soils that are not easily?
Permeable
150
Advantages of gravity flow irrigation?
Low initial cost
151
Disadvantages of gravity flow irrigation
High labor costs, land leveling needed, high water losses
152
Center pivot, lateral move water moves under pressure high investment at beginning
Sprinkler irrigation
153
Advantages to Sprinkler irrigation
Very uniform application
Lillte land preperation
Low labor costs
154
Disadvantages to Sprinkler irrigation
High initial cost
Energy needed to pressurize system
High evaportaive losses
155
Subsurface drip
sUrface drip
Initial cost $1200/AC, Delivers small amount of water, easy to control
Microirrigation
156
Advantages to Microirrigation?
Very efficient
| Low erosion
157
Disadvantages to microirrgation
High initial cost
Energy need to pressurize system
System may interfere with tillage
158
Irrigation water should be free of
Particulates and low in salt content
159
An association between a fungus and the roots of a plant
Mycorrhizae
160
Improves nutrient and water uptake
Mycorrhizae
161
Most plants form....associations
Mycorrhizae
162
Mycorrhizae is a what relatioship
Symbiotic
163
Non-mineral nutrients
Carbon
Hydrogen
Oxygen
164
Non-mineral nutrients account for how much dry weight?
96%
165
Macronutrients
```
Nitrogen
Phosphorus
Potassium
Sulfur
Calcium
Magnesium
```
166
Account for 3.5% of a plants dry weight
Macronutrients
167
Micronutrients
```
Iron
Zinc
Manganese
Copper
Boron
Chlorine
Moybdenum
```
168
Sources of Nitrogen, Phosphorus, and Potassium?
Synthetic fertilizer adn organic material (manure)
169
Is loam a type of soil particle?
No
170
Correct order for the soil horizon starting from the soil surface:
Horizon A, Horizon B, Horizon C, Horizon R
171
Physical Condition of the soil is?
Soil Tilth
172
Soil structure that is the arrangement of soil particles into groups. These groups are called?
Peds
173
Soil Structure associated with high organic matter?
Granular
174
Largest constituent of a typical soil?
Minerals
175
Why is tillage done?
To shape the soil, to manage pests, and to improve soil conditions
176
PWhich of the following is classified as a primary tillage implement? Tandem disk, Field Cultivator, Chisel Plow, or Lister
Chisel Plow
177
Advantage of a conventional tillage system?
Helps pest/weed control
178
Disadvantage of a conservational tillage system?
Increase dependence on herbicides
179
Name of the form of conservation tillage in which soil is undisturbed and weed control is accomplished with herbicides?
No Till
180
Characteristic of the conservation practice drain tile?
Removing excess water from soil surface
181
Type of viability test?
Rolled towel
182
Define germination?
Process of resuming growth in a seed
183
Source of agricultural seeds has the lowest quality seeds?
Farmer-saved seed
184
If a farmer plants too many seeds per acre?
Intraspecific competition
185
Advantage of the twin-row planting pattern
Better use of available space and increase the amount of plants per area
186
A small seeded crop should be planted
less deep in the soil
187
Measure of the total amount of water required to produce one unit of dry matter?
Water Use Efficiency
188
Oldest method of irrigation?
Gravity flow irrigation
189
Main disadvantage fo a center-pivot irrigation system?
High initial cost
190
Irrigation water of good quality sould be low in?
Salt
191
Irrigation should be done when?
Water potential is preventing plant uptake of water and when the crop is at the critical growth stage
192
Evapotranspiration differs from transpiration?
ET considers the water lost from the soil and by the plant; transpiration just considers the water lost by the plant.
193
Association between fungus adn roots?
Mycorrhizae
194
3 non-mineral nutrients that account for 96% of plant dry weight?
Carbon, Hydrogen, and Oxygen
195
What are magnesium, nitrogen, and sulfur
Macronutrients
196
Nutrients required in small concentrations?
Micronutrients
197
Organic fertilizers can be considered a good source of which nutrients?
Nitrogen and phosphorus
198
Non-mineral nutrients account for how much of the plants dry weight?
96%
199
What weeds are only allowed in small quantities in commercial seed?
Restricted noxious weeds
200
Accelerated aging tests can dtermine the what of seeds?
Vigor
201
Macronutrients are required in what amounts by the plant?
Large
202
Soils with what porosity have higher bulk density?
Low porosity
