Flashcards in Plant Growth Factors 2 Deck (41):
what makes up the physical soil texture?
the percentage of sand, silt and clay in soil
what is loam ?
an equal mixture of all 3 soil types
t or f loam is naturally occurring in nature
how many essential chemical element are there?
what 3 are obtained from air and water?
carbon oxygen and hydrogen
what are the 3 macronutrients?
what are the secondary nutrients?
what are 4 chemical properties?
2. mineral nutrition
4. cation exchange capacity
what is the cation exchange capacity
- index of soil fertility
-plant nutrients carry positive charge
-soil particle with large surface area are - charged
increases CEC = increase nutrients available for plants
chlorosis of older leaves is a symptom to what deficiency?
chlorosis of young leaves indicate deficiency of?
weak stems, roots and leaves indicate deficiency of?
imperfect cell development and delayed growth indicates deficiency of?
stunted growth indicates a deficiency of
what are the 5 observable symptoms of deficiencies ?
3. accumulation of anthocyanin = purple colour
4. lack of new growth
5. stunted growing
mobile deficiencies present of what age of leaves? what nutrients ?
-older leaves --> nutrients moved to newer tissues
-N, P, K, Mg, Cl, Zn
immobile deficiencies show on what type of leaves? What nutrients?
- younger leaves
-S, Fe, Cu, Mn, B, Ca
what is the chemical formula for a chlorophyll molecule?
on a chlorophyll molecule , Mg is ____ and Fe is ___. Mg shortage results in ___. Fe shortage results in ____.
-chlorotic older leaves
-chlorotic new growth
too much N can result in
-fast growth, long thin weak shoots, dark leaves and lack of flowering
what is phosphorus important for?
-root establishment, flowering
what is potassium important for ? symptoms of potassium deficiency?
- general health; chlorophyll formation, disease resistance
- small fruit, yellowing of older blooms, sickly
nutrient availability is affected by what 3 things?
2. temperature (slow colder temps)
3. pH (acid <7, alklaine >7)
how can you increase soil acidity? Decrease?
how do you improve soil fertility?
1. adjust pH
2. adjust organic matter
what is optimum germination temperature?
at what temp do roots stop growing?
5C or less
true or false; sandy soils warm faster than clay
typical mineral soil is comprised of what % air?
what is the water table?
- upper surface of ground level below which the soil is saturated with water
how to you prevent a perched water table?
1. well draining media
2. porous soil
3. drainage holes
what are the 3 components of the disease triangle?
1. susceptible host
2. favourable env't
what do plant roost exude that get eaten by pests?
what is the building block of amino acids?
in what forms does N get taken in by plant?
NH4( ammonium) and NO3 (nitrate)
t or f forests have a high population of fungi in their soils
t or f lower pH soils are dominated by bacteria
false; dominated by bacteria
-low pH soils dominated by fungi
perennials, trees and shrubs prefer what type of soil?
-fungally dominated, low pH (N in NH4 form)
annuals prefer what type of soil?
-bacterially dominated; n in NO3 form
bacteria is dependent on what? Role?
-primary decomposer (easy material)