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.