Exam 1 Flashcards
What is an essential element?
An element required for normal plant development
What is meant by a Macro-nutrient?
Nutrients needed in relatively large quantities
What is meant by a Micro-nutrient?
Nutrients needed in relatively small quanitities
What are the macro-nutrients? (6)
N-Nitrogen P-Phosphorous K-Potassium Mg-Magnesium S- Sulfur Ca-Calcium
What are the micro-nutrients? (6)
B-Boron Cu- Copper Fe- Iron Ma- Manganese Mo- Molybdenum Zn- Zinc
Compounds in which Nitrogen might be found?
Alfalfa
Clover
Manure
Soybeans (not removed)
How do plants respond to Nitrogen?
Dark green foliage
Higher protein content
Plants more succulent (more plump)
What might happen to the plant if it receives to much Nitrogen?
Weak stem (lodging)
Delayed flowering
Lower plant productivity quality
Quality reduction that might occur from to much Nitrogen.
Low sugar content Low vitamin content Bad color Reduced flower development Nitrate poising
Where is the majority of nitrogen on the planet?
In the atmosphere
Why is atmospheric Nitrogen unusable by plants?
The nitrogen is bound in chemical bonds that prevent the plant from absorbing it. The nitrogen must be transformed by nitrification.
Indicate the relative balance of organic vs inorganic Nitrogen in the soil
organic (1-5%)
Inorganic (95-99%)
*What makes an Nitrogen atom organic vs an inorganic atom?
*
What is the primary form of Nitrogen plants use?
NO3- Best
NO- Good
NH3 Good
What are the four source from which plants get Nitrogen?
Biological Fixation
Climatic
Natural Fertilizers
Synthetic Fertilizers
*Discuss the four inorganic Nitrogen molecule transformations discussed in class?
*
*Why are most organic Nitrogen molecules not usable by plants?
*because the atoms are bound together in an unavailable form
What is Mineralization of Nitrogen?
is the change in chemical structure from N2 to NO3
How is Nitrogen affected by decomposition of Organic Matter?
soil microbes need Nitrogen to break down organic matter the Carbon to Nitrogen ratio indicates the amount of nitrogen required to break down the material.
What is the carbon to nitrogen ratio of most plants?
Greater than 30 to 1
What is the final organic product of of the Organic Matter decomposition process?
Humus….C to N ratio of 10 to 1
Change in soil NO3- and carbon during the decomposition process?
Om added soil microbes eat carbon goes up, population of microbes goes up food runs out and microbes die carbon goes down and nitrogen increases
Name 3 ways by which producers can increase nitrogen in the soil?
Legumes
Organic Fertilizers
Synthetic Fertilizers
What percentage of Nitrogen is added through legumes?
natural fertilizers ? synthetic fertilizers?
25% legumes
14% natural fertilizers
57% synthetic fertilizers
What is the main reason why all of the Nitrogen fixed by legumes doesn’t always become available to plants?
*
Discuss the agronomic and economic issues surrounding the use of legumes?
Price per acre is low, cash crops are more profitable per acre. agriculturally legumes are extremely beneficial
What is the effect of adding Nitrogen to legumes?
legume bacteria stops working
Describe the speed at which nitrogen is released by natural nitrogen fertilizers?
The process usually takes 4 to 8 weeks. depending on weather conditions.
What factors determine the application rate of manure or sledge?
The source (ie chicken litter) and use
How do these factors affected the rates of manure or sludge?
Amount of Nitrogen needed and phosphorous levels of soil
Most synthetic fertilizers are derived from what primary fertilizer?
NH3 Anhydrous Ammonia
Describe the Habor process and indicate why Nitrogen fertilizers prices are dependent on energy cost?
*
Name 3 primary fertilizers and provide one fact about each?
Anhydrous Ammonia - Purest form, Gas
Urea- Pellet, Most common used in central Ky, acidify soil
Ammonia Nitrate- Heavily regulated acidify soils,
Ammonia nitrogen fertilizer factors
acidify the soil
volatilize when not incorporated
can injure seedlings
How does soil CEC affect NH4+ and NO3-?
determines how quickly Nitrogen changes form…NH4+ held longer NO3- not held.
What is the overall nitrogen balance on cropland?
more is applied than used
Consequences of over application of nitrogen?
nitrates in the water
Eutrophication (fish)
NO and N2O are pollutants
What are some major causes for NO3- losses?
cafo- Confined Animal Feeding Operations
high intensity cropland
sandy soils
