Lesson 4 – Fertilizing Soils Advanced Plant Science Mr. Dieckhoff

Where are we going… Types of Fertilizers Forms of Fertilizers Fertilizer Formulations Fertilizer Application Techniques Fertilizer Application Time Periods Calculating Fertilizer Application Rates

Types of Fertilizers Mineral Organic Limestone – good source of calcium, magnesium, and sulfur Phosphorus – phosphate rock – P2O5 Potassium – potash – K2O Organic Manures Chemical (inorganic) – manufactured from non-living sources Formulations of N, P, K

Forms of Fertilizer Fluid Pressurized Liquids Dry Slow Release

Fertilizer Formulations Fertilizer Grade %N - %P - %K To determine pounds of nutrient, take % x total pounds of fertilizer

Calculating Nutrients in Fertilizer How many pounds of nitrogen are in a 20 lb bag of 20-10-20 fertilizer? How many pounds of potassium are in a 10 lb bottle of 17-18-19 fertilizer? How many pounds of phosphorus are in a 50 lb tub of 24-18-20 fertilizer?

Calculating Nutrients in Fertilizer - Answers How many pounds of nitrogen are in a 20 lb bag of 20-10-20 fertilizer? 4 lbs How many pounds of potassium are in a 10 lb bottle of 17-18-19 fertilizer? 1.9 lbs How many pounds of phosphorus are in a 50 lb tub of 24-18-20 fertilizer? 9 lbs

Fertilizer Application Techniques Broadcasting Soil Injection

Fertilizer Application Techniques Banding Side-dressing

Fertilizer Application Techniques Top Dressing Foliar

Fertilizer Application Techniques Fertigation

When should fertilizer be applied? Soil Temperature – above freezing until 85 degrees Moisture – dry soil better Single vs. Split application Mobile (leaching) nutrients Fall – not in sandy soils, spread anhydrous ammonia Winter – anhydrous ammonia Spring – apply when planting Summer – side dressing & fertigation when needed

Fertilizer Rate Calculations To calculate amount of limestone: Lime is applied in pounds of ENM (effective neutralizing material) ENM value from soil test divide by ENM of limestone Example, if soil test calls for 1,450 lbs/ac and dealer guarentees 400 lbs ENM per ton: 1,450 lb/ac divide 400 lbs ENM/ton = 3.63 ton/ac

Soil Test Recommendations: P = 70 K = 50 Total acres to spread is 75.   Fertilizer Sources and Costs per pound: Diammonium Phosphate 18-46-0 $ 0.07 Ammonium Nitrate 34-0-0 $ 0.14 Potassium Chloride 0-0-60 $ 0.08 Spreading charge is $3.00 per acre.

Match the definition on the left to the term on the right. 1. ____ Application technique for anhydrous ammonia.   2. ____ Method used to fertilize pastures. 3. ____ Used when planting to stimulate seed germination. 4. ____ Dry fertilizer placed to each side and below seed. 5. ____ Spreading dry fertilizer over soil prior to planting. 6. ____ Application of fertilizer in irrigation systems. 7. ____ Fertilizer applied directly to leaves of plants. 8. ____ Fertilizer applied 6 to 8 inches from the plant row. a. Broadcasting b. Soil injection c. Banding d. Starter applications e. Side-dressing f. Top-dressing g. Foliar h. Fertigation