Soils fert test 1 Flashcards
Grew a willow tree only using rain/distilled water
His theory was wrong but contributed to science
Jon Baptiste
Repeated and confirmed Baptiste experiement with willow and water,analyzed plant samples,believed plants contained spirits,salts,earth and oil (lipids) were formed from water
Robert Boyle
Suggested that saltpeter made plants grow and that it was the prinicple nourishment and not water
Collected soil from cattle pens and found it was high in KNO3 then applied to plants and saw an increase in growth
J.R. Glauber
Grew spearmint in rainwater(small),river water(med),sewage (big) sewage waste with a different concentration (bigger) the growth of water was proportional to the amount of impurities in the water Conclusion was that the earth was the prinicple in vegetation
John Woodward
Dicovered oxygen,plants and animals respire by brining organic food,increase in weight because they fixed CO2,plants take up nutrient ions
Priestley
Plants get most of their C from CO2,water is the source of hydrogen and oxygen,soil is the source of elements in the ash
Justus Von Liebig
A status of a soil to supply elements essential for plant growth w/o a toxic concentration of any element
soil fertility
What effect has technology had on crop production?
Nitrogen,breeding and genetics,weed control,Ag practice (ex: no till)
Decrease in yeilds depend on…
Crop,soil,climatic region
If we stopped using fertilizers we will have to increase land by _____ to _____ %
30-40
Highest yeilds you can get from a crop when all factors are present
yeild potential
What factors effect crop growth?
There are over 50 factors but there are 3 groups:Climatic Factors,Soil factors,Crop factors
What are examples of climatic factors?
Precipitation,relative humidity,Air temp,light,altitude,wind,CO2
Whats are examples of soil factors?
Organic matter,Texture,structure,Cation exchange capacity,base saturation,Slope and topography,soil temp,soil depth,soil management factors
What are examples of crop factors
Crop species and variety,Planting date,seeding rate and geometry,seed quality,evapotranspiration,water availabilty,nutrition,pests,harvest efficiency
What have genetic factors done for crop production?
Increased wheat and corn yeild potential,genetic engineering-higher yeilding varieties,modern hybrids and varieties require more plant nutrients
Why do plants use a great deal of available solar energy to achieve high yeilds?
Because max potential yeilds based on available solar energy for most crops exceeds current crop yeilds
What are the max potential yeilds for corn,soybean,and wheat?
Corn 600 bu/acre Soybeans 250 bu/acre wheat 300 bu/acre
What are the 3 global stresses that reduce crop yeilds?
Plant available water,temp,nutrient availabilty
To achieve high yeilds why most both controllable and uncontrollable must operate in unison?
Cont and uncont factors are interrelated and they can work together to either increase or decrease plant yield
What is law of the minimum?
The most limiting factor will detirmine yeild potential
nutrient availability is eesential for max plant growth and yeild potential
How many nutrients are considered essential elements?
17
What is an essential element?
One that is required for plant growth and developement
Plants cannot complete life cycle w.o this element
Involved in metabolic function of plants
Basic molecular components of carbs,proteins,lipids,and nucleic acids
Carbon
Like carbon and occurs in all organic compounds
Oxygen
Plays central role in plant metabolism
hydrogen
Component of many important organic compounds from proteins to nucleic acids
nitrogen
Central role in plant energy tranfer and protein metabolism ATP
Phosphorus
Activates over 80 enzymes and plays a role in osmotic and ionic regulations
Potassium
Plays a major role in cell division
Calcium
Component of chlorophyll and cofactor of enzymatic activities
Magnesium
Cell enerrgetics
Sulfur
What two groups are essential elements divided into?
Macro and mircro
What are the 3 ways the amount of elements in the soil system be detirmined?
Soil test,tissue,test,deficiency symptomes
When a concentration is low enough to severely limit yeild
Deficiency
The nutrient concentraion in the plant below which a yeild response to added nutrients occurs
Critical range
Nutrient concentration range in which added nutrients will not increase yeild but can increase nutrient concentration
Sufficient
When concentration of essential element or other elements is high enough to reduce plant growth and yeild
Excessive or toxic
Which has a greater effect on growth correction of deficiency or nutrient concentration?
deficiency correction
What are the most abundant nutrients in plants?
C,H,O these are found in water and CO2 and ultilized in photosynthesis
What two components are used to make carbs?
CO2 and H2O
What are carbs used for in the plant?
Synthesize amino acids,proteins,sugars,nucleic acid and other organic compounds
Classifcation of essential elements is based on…
The amount consumed by the plant
What are macro elements?
N,P,K,S,Ca,Mg
What are micro elements?
Fe,Cl,Zn,Molybdenum,Manganese,Na,Cu, and cobalt
What are the 2 forms of nitrogen absorbed by plants?
NH4+ and N03-
plays a major role in protein formation,photosynthesis?
nitrogen
functions in energy storage and transfer
Phosphorus
acts as an energy currency within plants and powers every engery requiring biological process in plants
ATP
What key roles does potassium play in plants?
Enzyme activation,H2O relationns (osmosis and transpiration) energy relations,translocation of assimilates,nitrogen uptake
This is the passive transport of nutrients to the root in soil water
Mass flow
the amount of the nutrients reaching the root by mass flow depends on what 3 factors
1.Concentration of nutrients in soil solution,rate of H2O transport and rate of H2O flow into roots
what affects water uptake by plants and has an effect on nutrient uptake by mass flow?
Transpiration rate
What 4 factors affect nutirent supply by mass flow?
soi; properties,climatic conditions,solubility of the nutrients,and plant species
Mass flow can meet the crop nutrient req. for all nutrients except…
N,P,K,Fe,Mg
Why cant mass flow meet the nutrient req for N,P,K,Fe,Mg?
mass flow supplies most mobile elements to the roots
What are the mobile nutrients?
Negatively charged- NO3,Cl- and So42-
The movement of ions from areas for high concentration to low concentration
diffusion
what to elements are moved to the roots by diffusion?
P and K
When does diffusion take place?
when the supply of nutrients to the root vicinity is not sufficient to satisfy the plant demand by mass flow and root interception
the rate of diffusion is directly proportional to the….
concetration gradient
what two processes are inportant to supplying ions to the plant root?
Diffusion and mass flow
The _____ phase has to supply the ____ liquid phase with the ions
solid,liquid
in what form are nutrients absorbed?
ionic
What kind of process is ion uptake by intake plants?
Catenary
once ions enter the root cell they are transported from cell to cell towards the ______.
xylem
What 2 ways does ion uptake occur?
Actively and passively
absorbed by the root hairs move through the epidermis,cortex,endodermis,and stele to finally reach the xylem for transport
ions
The xylem transports the ____. the pholleum supplies ____.
H2O and elements,photosynthates
active nutrient uptake requires____ and occur across plant cells
energy
the plasma membrane is selective based on ______.
permeability
