PLANT REQUIREMENTS
Topic # 2031
Mr. Christensen
Nutrients
• Plants needs more than carbon dioxide (CO2), water (H2O) and light they also require-----
• Macronutrients—Required in larger quantities than others.
• Micronutrients—Needed but in smaller amounts
Essential Plant Nutrients
• Non-Fertilizers obtained from the air and water—Carbon(C) Hydrogen (H) and Oxygen (O)
• Primary Macronutrients—Nitrogen (N), Phosphorus (P), Potassium (K),
Essential Plant Nutrients
• Secondary Macronutrients—Calcium (Ca), Magnesium (Mg) and Sulfur (S)
• Micronutrients—Boron (B), Copper (Cu), Chlorine (Cl), Iron (Fe), Manganese (Mn), Molybdenum (Mo), Zinc (Zn) and Nickel (Ni)
Nitrogen Cycle
Physical Geography http://www.physicalgeography.net/fundamentals/9s.html
Nitrogen
• Constituent of amino acids, chlorophyll and nucleic acids
• Plant absorbs as NO3-, NH4+, and NO2
-
• Deficiency symptoms—stunting, pale green leaves (chlorosis) and firing of lower leaves (firing of tip down the mid-vein)
• Mobile in the plant and soil (leaching and denitrification)
Iowa State University, http://www.ent.iastate.edu/imagegal/plantpath/corn/deficiency/ndeficiency.html
N DeficiencyChlorosis
Side-dressing cornWith 28% N
Iowa State University, http://www.ent.iastate.edu/imagegal/plantpath/corn/deficiency/ndeficiency.html
28% N Fertilizer Burn
Phosphorus
• Important in energy release, constituent of ATP and nucleic acids, necessary for normal development of flowers, fruits and seeds.
• Plant absorbs as H2PO4- (acid soils) and HPO4
=, and PO4
= (alkaline soils)• Deficiency symptoms—Purpling of lower leaves,
flowers abort before forming.• Mobile in the plant and fixed in the soil• Most Michigan soils are high in P
Phosphorus Deficiency
Mississippi State University http://msucares.com/crops/corn/corn-stuted.html
Iowa State University http://maize.agron.iastate.edu/images/corn/Fig55.gif
N use in a corn plantOver time
P use in corn plantOver time
Timing and Nitrogen Rate Application Effect on Corn Yield• Irrigated McBride Sandy Loam Application Timing N rate Preplant Sidedress Lb N/acre -----------bu/acre 0 75 75 120 149 155 180 155 161 240 157 167 For profit 200 Lb N/acre for Records 400Lb N/acre
Why less productionFor N applied preplant
Diminishing Returns?
Potassium
• Important in translocation; affects cell permeability, stomatal activity, activator of many enzymes
• Plant absorbs as K+
• Deficiency symptoms—Scorch or necrotic spotting (yellowish/reddish) of lower leaves (tips to margins), weak stalks
Potassium Deficiency
Iowa State University, http://www.ent.iastate.edu/imagegal/plantpath/corn/deficiency/ndeficiency.html
K use in Corn Over time
Iowa State University http://maize.agron.iastate.edu/images/corn/Fig55.gif
Reading the Fertilizer Label
J.I. Simplot Company http://www.bestfertilizer.com/index.cfm?page=32
1st Number Nitrogen (N) %
2nd Number Phosphorus (P)%
3rd Number Potassium (K)%
Urea 46% NAnhydrous Ammonia 82% Ammonium Sulfate 21%
Fertilizer Calculations
• 50 Lbs of fertilizer marked 16-04-08
• How many pounds of Nitrogen, Phosphorus and Potassium does the bag contain?
Nitrogen .16 X 50 = 8.0 Lbs
Phosphorus .04 X 50 = 2.0 Lbs
Potassium .08X 50 = 4.0 Lbs
Fertilizer Calculations
• 25 lbs of fertilizer marked 34-06-12
• How many pounds of Nitrogen, Phosphorus and Potassium does the bag contain?
Fertilizer Calculations
• Nitrogen .34 X 25 = 8.5 Lbs.
• Phosphorus .06 X 25 = 1.5 Lbs.
• Potassium .12 X 25 = 3 Lbs.
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