1. CRSS 2830 Lesson 8 Fertilization

2. PLANT NUTRIENTS 16 essential nutrients

3. Carbon, hydrogen and oxygen obtained from water and airCarbon, hydrogen and oxygen obtained from water and air Remaining 13 divided into three groups:Remaining 13 divided into three groups:

4. PLANT NUTRIENTS Three Groups:Three Groups: –Primary: nitrogen, phosphorus, potassium –Secondary: Calcium, magnesium, and sulfur –Micronutrients: Iron, manganese copper, boron, zinc, chlorine, molybdenum

5. FERTILIZERS Complete fertilizer = N-P-KComplete fertilizer = N-P-K Fertilizer grade = minimum guaranteed analysis

6. FERTILIZERS 20-5-10 = 20 %N, 5% P2O5, 10% K2O20-5-10 = 20 %N, 5% P2O5, 10% K2O Therefore, a 50 pound bag would contain...Therefore, a 50 pound bag would contain... –N = 10 lbs –P2O5 = 2.5 lbs –K2O = 5 lbs

7. FERTILIZERS Fertilizer RatioFertilizer Ratio –20-5-10 = 4-1-2 ratio –30-10-10 = 3-1-1 ratio –10-5-20 = 2-1-4 ratio

8. FERTILIZERS How much 20-5-10 must be applied to achieve 1 lb of N/1000 sq. ft.? How much 20-5-10 should be applied to a 6000 sq. ft. lawn? –1/.20 = 5 lbs of 20-5-10/1000 sq. ft. –5 lbs./1000 sq. ft. X 6 = 30 lbs of 20-5-10 (Not 6 lbs of 20-5-10)

9. NITROGEN Used in greatest amountsUsed in greatest amounts Most fertility programs based on nitrogenMost fertility programs based on nitrogen Too much will encourage disease and reduce root growthToo much will encourage disease and reduce root growth

10. TURF QUALITY AND ROOT GROWTH AFFECTED BY NITROGEN RATE QUALITY RATING Lbs. N / 1000 sq. ft. / Year 3 2 1 0 ROOT WEIGHT (g / sq. dm ROOT WEIGHT (g / sq. dm) QUALITY ROOT WEIGHT

12. NITROGEN Types of Nitrogen FertilizersTypes of Nitrogen Fertilizers –Soluble or fast release –Insoluble or slow release

13. NITROGEN Soluble FertilizersSoluble Fertilizers –Ammonium nitrate 33% –Ammonium sulfate 21% –Potassium nitrate 13% –Urea 45%

14. NITROGEN Insoluble FertilizersInsoluble Fertilizers –IBDU (isobutylidenediurea) 31 % –UF (ureaformaldhyde) 38 % –Methylene urea 38 % –Sulfur coated urea 32 % –Poly coated urea 39-44% –Natural organics 3 - 11% (cow, chicken manure, dried blood, etc.)

15. PHOSPHORUS Critical at establishment Not prone to leachingNot prone to leaching Promotes rootingPromotes rooting

16. POTASSIUM Important for stress toleranceImportant for stress tolerance –(heat, cold, drought, traffic, diseases, etc) traffic, diseases, etc) Will leachWill leach

17. IRON Most often applied micronutrientMost often applied micronutrient

18. WHEN TO FERTILIZE Beginning or during favorable growth conditionsBeginning or during favorable growth conditions Cool seasonCool season –Spring (light) –Late summer/early fall –Late fall –Rarely summer

19. WHEN TO FERTILIZE WarmWarm season –Late –Late spring –Summer –Possibly –Possibly early spring and late summer

20. HOW MUCH TO APPLY Depends on:Depends on: –Species (refer to book) –Season –Type of fertilizer –Environment (shade vs. sun) (shade vs. sun)

21. APPLICATION METHODS GranularGranular LiquidLiquid (same to the plant)(same to the plant)

22. GRANULAR APPLICATION rotary rotary drop-typedrop-type (Apply to dry turf and water in) (Apply to dry turf and water in)

23. LIQUID APPLICATION drench (3 to 5 gals/1000 sq. ft.)drench (3 to 5 gals/1000 sq. ft.) foliar (< 1 gal/1000 sq. ft.)foliar (< 1 gal/1000 sq. ft.) fertigation (applied via irrigation system)fertigation (applied via irrigation system)