Fertilizers

Fertilizers What are the numbers?What are the numbers? –N, P 2 O 5, K 2 O –“primary” macronutrients Nutrients derived from…Nutrients derived from…

Fertilizers Secondary macronutrientsSecondary macronutrients MicronutrientsMicronutrients

Nitrogen breakdownNitrogen breakdown

Organic fertilizersOrganic fertilizers –Kelp meal

Organic fertilizersOrganic fertilizers –Feather Meal to (different suppliers) –Slow release!

Organic fertilizersOrganic fertilizers –Green sand 0-0-3

lbs/acre ÷ = oz/1,000 ft 2

Application Strategy Soil Test ResponseSoil Test Response –Preplant Adjustments pH (liming) 100%pH (liming) 100% –Dolomitic limestone (CaMg)(CO 3 ) 2 –Calcitic limestone CaCO 3 Calcium (Ca) / Magnesium (Mg) 100%Calcium (Ca) / Magnesium (Mg) 100% –If pH is ok & Ca needed: gypsum CaSO 4 2H 2 O –If pH is ok & Mg needed: Epsom salt MgSO 4 7H 2 O Phosphorus (P 2 O 5 ) 100%Phosphorus (P 2 O 5 ) 100% Potassium (K 2 O) 30 to 50% (unless slow-release)Potassium (K 2 O) 30 to 50% (unless slow-release) Nitrogen (N) 30 to 50% (unless slow-release)Nitrogen (N) 30 to 50% (unless slow-release) Sulfur (S) – Epsom salt or other sulfate fertilizer 100%Sulfur (S) – Epsom salt or other sulfate fertilizer 100% –Micronutrients (B, Cl, Cu, Fe, Mn, Mo, Zn)? Usually not in soil test unless requested (UGA does Zn and Mn in routine tests); usually not deficientUsually not in soil test unless requested (UGA does Zn and Mn in routine tests); usually not deficient

Application Strategy Soil Test ResponseSoil Test Response –Postplant Adjustments Potassium (K 2 O) 50 to 70% as sidedress (as-needed for SRF)Potassium (K 2 O) 50 to 70% as sidedress (as-needed for SRF)sidedress Nitrogen (N) 50 to 70% as sidedress (as-needed for SRF)Nitrogen (N) 50 to 70% as sidedress (as-needed for SRF)