PLANT REQUIREMENTS Topic # 2031 Mr. Christensen

Nutrients Plants needs more than carbon dioxide (CO 2 ), water (H 2 O) 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

Nitrogen Constituent of amino acids, chlorophyll and nucleic acids Plant absorbs as NO 3 -, NH 4 +, and NO 2 - 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, N Deficiency Chlorosis Side-dressing corn With 28% N

Iowa State University, 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 H 2 PO 4 - (acid soils) and HPO 4 =, and PO 4 = (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

Iowa State University N use in a corn plant Over time P use in corn plant Over 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 For profit 200 Lb N/acre for Records 400Lb N/acre Why less production For 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,

K use in Corn Over time Iowa State University

Reading the Fertilizer Label J.I. Simplot Company 1 st Number Nitrogen (N) % 2 nd Number Phosphorus (P)% 3 rd Number Potassium (K)% Urea 46% N Anhydrous Ammonia 82% Ammonium Sulfate 21%

Fertilizer Calculations 50 Lbs of fertilizer marked 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 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.