Test 2

Question 0

Hydrologic cycle

Answer 0

All life depends on and involves run off and excess water

Question 1

Water balance

Answer 1

P=et+ss+d

Et=evapotranspiration
Ss=soil storage
D=discharge

Question 2

Soil plant atmosphere continuum

Answer 2

Water moves from soil to plants to the atmosphere and back to soil

Question 3

Water deficit

Answer 3

Potential water evaporation - evapotranspiration

Is considered a measure of plant stress

Question 4

Conservation tillage

Answer 4

Leaving plant residues on surface to minimize both evaporation loses and erosion

Question 5

Two ways water leaves the soil

Answer 5

Through percolation or drainage that carries with it plant nutrients, pesticides and other dissolved chemicals that can move into groundwater and nearby streams

Through runoff water that carries with it plant nutrients as well as the finer fractions of the soil itself through soil erosion

Question 6

Preferential flow

Answer 6

Percolating water moving rapidly through very large macro pores such as those formed by root holes and earth worms

Question 7

Vadose zone

Answer 7

The unsaturated zone above the water table

Question 8

Capillary fringe

Answer 8

Zone of unsaturated material directly above groundwater table and part of vadose Zone

Question 9

Problems with preferential flow

Answer 9

Brings chemicals and solubles down farther in the soil profile

Question 10

Open ditches

Answer 10

Drainage method used to lower the water table in a poorly drained soil

Question 11

Buried tile lines

Answer 11

Perforated plastic pipe that acts in the same way as an open ditch yet it is not visible and doesn’t provide an obstacle.

Question 12

Footer drain

Answer 12

Used around foundation of the house to keep water level lower and prevent flooded basements. Topsoil is angled away and a drainage pipe is present.

Question 13

Septic tank

Answer 13

Wastewater from homes is piped to a concrete box where the solids settle out and decompose. The liquid effluent overflows into a series of perforated pipes buried which operate in the opposite way of the drainage system

Question 14

Perc test

Answer 14

Used to check for permeability for septic tank

Question 15

Micro irrigation

Answer 15

Trickle or drip systems that apply very small quantities of water directly onto the plant and is the most efficient method

Question 16

Soil aeration

Answer 16

Influences most chemical physical and biological processes in soils

Question 17

Hydrophytic plants

Answer 17

Plants that can adapt to saturated conditions due to aerenchyma tissues that allow them to thrive in water saturated conditions by getting oxygen from the atmosphere

Question 18

Gases in soil air

Answer 18

Nitrogen, oxygen and carbon dioxide

Nitrogen is about 78 percent
Oxygen is about 21
Co2 is definitely higher than that of atmosphere at .035

Question 19

Aeration status of soil can be determined by:

Answer 19

The O2 content in the soil
The proportion of the pores pace filled with air
The oxidation reduction potential of the soil

Question 20

Redox potential

Answer 20

Gives an indication of the tendency of the soil to accept or donate electrons which infuences the ionic species of several elements in the soils.
Measures in Millivolts
400-700 indicates oxidizing conditions
300 to -300 suggest reducing conditions

Question 21

Colors of redox status

Answer 21

Red and brown colors indicate oxidized Fe and Mn compounds

The Blues and Grays predominating under reduced conditions

Question 22

Factors influencing soil temperature

Answer 22

Soil radiation
The specific heat of a soil
Energy needed to evaporate soil water

Question 23

Colloidal particles

Answer 23

Very small in size at less than 2 micrometers in diameter and are made up of clay and/or humus.
Carry negative or positive changes that attract particles
The absorbed ions are subject to exchange with plant roots thereby providing plants with most of their essential mineral elements

Question 24

4 colloidal particles

Answer 24

Crystalline silicate clays Allophane and associated non-crystalline silicate clays Hydrous iron and aluminum oxide clays Humus

Question 25

Silicate clays

Answer 25

Found all over the world but most prominently in temperate regions

Question 26

Allophane

Answer 26

Most prominent in volcanic regions

Question 27

Oxide clays

Answer 27

Prominent in soils of the tropics

Question 28

Humus

Answer 28

Found wherever organic residues are

Question 29

Kaolinite

Answer 29

1:1 as in one tetra to octa Non expanding and no swelling .7nm Little isomorphous substitution and therefore low cation exchange

Question 30

Smectite

Answer 30

2:1 T/O/T Expanding and max swelling 1-2 nm between groups

Question 31

Vermiculite

Answer 31

2:1 Expanding and some swelling 1.0-1.5 nm Expansive cation holding capabity

Question 32

Fine grained mica

Answer 32

2:1 Non expanding Minimum swelling Has higher cation exchange is higher than 1:1 but lower than other 2:1 clays

Question 33

Chlorite

Answer 33

2:1 Non expanding Minimum swelling 1.4nm

Question 34

Tetrahedral

Answer 34

Silica sheet called a tetra hedral sheet because of the four sides configuration and associated oxygen atoms. 4 SIDED

Question 35

Octahedral

Answer 35

Aluminum and magnesium sheets comprise eight sided building blocks

Question 36

Isomorphous substitution

Answer 36

Ions having nearly the same radius as a silicon atom can fit in the tetrahedral sheet. Once this occurs the crystal is negatively charged attracting cations which then exchange with plant roots

Question 37

Soil acidity or alkalinity

Answer 37

Expressed as soil ph, it determines which plants dominate natural landscape and which crops can be grown

Question 38

Natural ph levels in different environments

Answer 38

Acidity in humid environments and alkalinity in arid environments.

Question 39

pH scale

Answer 39

Natural rain and souls are 5.5 to 6 and pure water is 7 | Battery acid is 1 and bleach is 12

Question 40

Causes of alkalinity

Answer 40

Caused when hydroxyl ions from carbonates and biocarbonates react with water

Question 41

Role of aluminum

Answer 41

Another principle acid cation besides hydrogen, it's hydrolysis reactions produce H- ions and its toxicity comprise one of the main detrimental effects of soil acidity.

Question 42

Active acidity

Answer 42

A measure of the H + ion activity in the soil solution. Quantity of H+ ions in this form is very small.

Question 43

Salt replaceable acidity

Answer 43

Gives an indication of the exchangeable Al3- and H+ present on the exchange complex and is equivalent to 200-2000 kg CaCO3 per hectare furrow slice

Question 44

Remaining acidity

Answer 44

Mostly associated with aluminum and hydrogen ions that are tightly bound by the organic matter and silicate clays. The amount of residual acidity is commonly much higher than even the salt replaceable form and may be as high as 5000-20000 kg CaCO3 per hectare

Question 45

Total acidity

Answer 45

Must be overcome to raise soil ph to a desired value

Question 46

Total acidity definition

Answer 46

Sum of active, exchangeable and residual pools of soil acidity (salt replaceable)

Question 47

Acidifying agents

Answer 47

This can be done by applying quantities of organic material, sulfur

Question 48

Liming

Answer 48

Used to balance the loss of calcium and magnesium in the soil to decrease soil acidity

Question 49

Saline soils

Answer 49

pH value of 8,5 or less

Question 50

Sodic soils

Answer 50

Have the sodium levels of Saline-sonic soils without the moderating influences of the neutral salts. PH greater than 8.5

Question 51

Flocculation

Answer 51

Ability for colloids to form and stick together

Question 52

Primary producers

Answer 52

Higher plants and algae

Question 53

Nematodes

Answer 53

Highly diverse tiny roundworms. A few species attack plant roots

Question 54

Rhizosphere

Answer 54

Populated by a greater abundance and diversity of microorganisms than is the bulk soil