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