C4- Soil Fertility And Evaluatiom Flashcards
refers to the inherent capacity of the soil to
provide nutrients to plants in the right amount and correct
proportions
Soil fertility
capability of a soil for producing plants
under a specified system of management
Soil productivity
Is one of the factors of soil productivity.
Sometimes a soil may be fertile but may not be productive.
Fertility
is measured by the amount of chemical elements
or compounds required for plant growth
Fertility
is measured by the yield of the crop per unit
area of the land
Productivity
The following are Biological test. Except:
a. Field trials
b. Pot culture/greenhouse trials
c. Use of indicator plants
d. Plant tissue test
e. Microbial test
D.
.- uniform or
interveinal yellowing or
light green coloring
leaves
Chlorosis
death of leaf
tips/leaf tissue, tissue
browns and die
Necrosis
Reddening or purplish color-
due to accumulation of___?
anthocyanins
reduced plant height
and shortened internodes
Stunting
death of new shoots,
terminal/axillary buds or
flowers, new leaves die
back or exhibit rossetting
New growth cessation
Older leaves pale first
o New leaves are
smaller
o Reduced branching
These are symptoms of what deficiency?
Nitrogen deficiency symptoms
urea fertilizer grade?
46-0-0
▪ Fertilizer grade: 21-0-0-24S
▪ Contains 24% S
▪ Soluble, readily available source of N
and S
What fertilizer is this
Ammonium sulfate: (NH4)2SO4
Fertilizer grade: 82-0-0
▪ Fertilizer with the highest analysis
of N
▪ Stored as a liquid under pressure
▪ Injected in the soils as a gas
▪ Highly caustic: requires use of
protective equipment, and subject
to regulations (use, transport, etc.)
Anhydrous ammonia: NH3
Fertilizer grade: 34-0-0
▪ Physical form: solid or liquid
▪ Hygroscopic: absorbs water from the air
▪ Can cause salt toxicity
Ammonium nitrate: NH4NO3
Fertilizer grade: 28-0-0 TO 32-0-0
▪ Soluble, readily available N source
▪ Liquid fertilizer product made by
dissolving urea and ammonium nitrate
in water
▪ Urea portion is subject to NH3
volatilization
Urea ammonium nitrate solution (UAN):
Urea+ NH4NO3
Application rate of chucken manure and vermicast
Application rate: 5-10 t ha-1
%N chicken manure
2.08%
Dwarf and stunted plants
o Slow growth
o Purpling of stem and
underside of leaves
Deficiency symptoms of what?
Phosphorus deficiency
Fertilizer grade: 0-18-0
▪ Physical form: solid
▪ Generally very insoluble
Solophos
▪ Fertilizer grade: 0-46-0
▪ Physical form: solid
▪ Acidifying agent
▪ Water-soluble
A. Triple superphosphate: Ca(H2PO4)2
B. Monoammonium phosphate: NH4H2PO4
C. Diammonium phosphate: (NH4)2H2PO4
D. Ammonium polyphosphate:
Ca(NH4H2PO4)2
A.
▪ Fertilizer grade: 11-52-0
▪ Physical form: solid
▪ Soluble, readily available source of P
and N
▪ May create an acidic zone around fertilizer granules
A. Triple superphosphate: Ca(H2PO4)2
B. Monoammonium phosphate: NH4H2PO4
C. Diammonium phosphate: (NH4)2H2PO4
D. Ammonium polyphosphate:
Ca(NH4H2PO4)2
B.
▪ Fertilizer grade: 18-46-0
▪ Physical form: solid
▪ Soluble, readily available source of P
and N
▪ Initial soil reaction can produce free
NH3(high pH, basic) which can cause
seedling injury if too much is placed
near the seed
A. Triple superphosphate: Ca(H2PO4)2
B. Monoammonium phosphate: NH4H2PO4
C. Diammonium phosphate: (NH4)2H2PO4
D. Ammonium polyphosphate:
Ca(NH4H2PO4)2
C.
Fertilizer grade: 10-34-0 or 11-37-0
▪ Physical form: liquid
▪ Soluble, readily available source of P
and N
▪ Popular source for starter fertilizer
A. Triple superphosphate: Ca(H2PO4)2
B. Monoammonium phosphate: NH4H2PO4
C. Diammonium phosphate: (NH4)2H2PO4
D. Ammonium polyphosphate:
Ca(NH4H2PO4)2
D.
o Chlorosis of the leaf
margin
o Leaf necrosis
o Green veins with curled
leaves
o Blotchy ripening in
tomato
____deficiency symptoms
Potassium
The ff are Calcium deficiency symptoms. EXCEPT
o Blossom end-rot
o Water-soaked spot
o Downward cupped leaves
o Reduced leaf size
o Purpling of stem and
underside of leaves
Purpling of stem and
underside of leaves
o Interveinal chlorosis on
older leaves
o Leaf margins curl
upward
o Stunted growth
o Ripe fruit is not sweet
_______deficiency symptoms
Magnesium
o Misshapen papaya
fruits
o Deformed sweet
potato roots
o Hollow heart in
peanut/mango/caulifl
ower
o Hollowness in tomato
____deficiency symptoms
Boron
Application rate of ferrous sulfate
0.4%
Soil factor resulting in deficiency
“Excessive on coarse-textured low organic matter soils”
N, k
The term used to describe a plant that
shows no obvious deficiency symptoms, yet the nutrient
content is not sufficient to give the top profitable yield
Hidden hunger
T or f
Fertilization with sure rate rather than the bare
economic optimum for an average leaf helps to obtain the top profitable yield.
T
A quantitative analysis based on the concept that if the
content of a particular nutrient in the plant is greater the
higher its availability in the soil
Plant tissue analysis
There is no basic relationship between the content of a plant
nutrient and the growth or yield of the plant.
T or f?
F- THERE IS A BASIC RELATIONSHIP between the content of a plant
nutrient and the growth or yield of the plant
the most critical stage of growth for tissue
testing is at the time of bloom or from bloom to early fruiting
stage
T/f?
T
“Factors affecting essential nutrient element concentration in plants”
-soil tilth, structure, compaction, soil
surface conditions
A. Soil chemical factors-
B. Treatment factors-
C. Soil physical factors
D. Crop factors
C.
organic matter content, water pH, level of essential elements
A. Soil chemical factors-
B. Treatment factors-
C. Soil physical factors
D. Crop factors
A
Serves an option to monitor the fertility of the soil while the
plant is already growing
Plant tissue analysis
• Estimates the nutrient
supplying capacity of a soil.
• Measures a portion of a
nutrient that is used by plants.
• Results are used to generate
fertilizer recommendation.
• Determine soil’s nutrient
status before a crop is planted.
Soil chemical analysis:
____% of all errors in
fertilizer recommendations
based on soil test is due to
poor soil sampling procedures
90%
Tools needed during soil sampling:
auger
shovel
bolo
pale
trowel
marker
sando bag
Using the zig-zag sampling, take at least 10-15 samples
and mix inside the pale
T or f
F- 10-20 samples
Topsoil-_____ cm depth for shallow rooted crops such
as rice, corn & vegetables.
0 to 25cm
Subsoil- ___cm depth for fruit trees such as
mango & coconut.
25 to 50 cm
Soil testing should be done every 1-2 years
T or f
T
This involves the planting of the crop in the soil being
evaluated
❖Plants are grown in different levels of nutrients and the
growth and yield performance of the crop is monitored and
compared.
Biological test
Biological test could either be?
a. pot experiment
b. field fertilizer experiment
determines lime requirement of soil
❑ indicator of Ca, P and K deficiency
A. Aspergillus niger test
B. Azotobacter plaque test
C. Cunninghamella plaque test
D. CO2 evolution
B.
❑ determine P, K, Cu, Mg, Mo, Co, Mn requirement of plants
❑ color of mycelia and spores are indicator of Cu & Mn
present in soil
A. Aspergillus niger test
B. Azotobacter plaque test
C. Cunninghamella plaque test
D. CO2 evolution
A.
determines P content in soil
❑ size of mycelia indicates P supply in soil
A. Aspergillus niger test
B. Azotobacter plaque test
C. Cunninghamella plaque test
D. CO2 evolution
C
To determine Potassium deficiency, a small amounts of soil are
incubated for a period of___ days in flasks containing appropriate solutions.
4 days
The organism_____ is sensitive to the
phosphorus status of the growing medium.
Cunninghamella
Cunninghamella blakesleana is used in____ soil
Calcareous soil
It is based on the principle of intensive uptake of nutrient elements by
growing a large no. of seedlings on a small quantity of soil
Neubauer Seedling method
In this technique, 100 seedlings of rye are made to feed exhaustively on
100 g of soil mixed with 50g sand (Nutrient free quartz) for 17 days in petri
dishes of (11 cmx7cm). A blank without any soil is also
run.
Neubauer Seedling method
