Turfgrass Nutrition

Soil Test Six inches deep Mix up a pint When? – establishment to till into soil – yearly or other year

Nitrogen Deficiency symptoms Chlorosis (yellowing) – Turf will look hungry Slow growth – Amount of clippings collected

Nitrogen Excessive N Reduced root growth – Increased shoot to root ratio More shoots, fewer roots

Nitrogen Excessive N Increase thatch accumulation

Nitrogen Excessive N Succulent growth – Prone to disease and insect – Cells walls are thinner

Phosphorus Importance is in the root growth

Phosphorus Starter fertilizers are high in P Limited root systems Higher demand for P during early stages

Phosphorus Immobile nutrient Will not move into the soil solution Extremely fibrous root system will get it Fertilizers generally low in P

Phosphorus P deficiency Purple discoloration Rarely seen in turf Don’t confuse with cold

POTASSIUM Stress nutrient Improves heat and cold tolerance

POTASSIUM Deficiency symptoms not distinct Best used in 1:1 ratios with N

IRON Micronutrient most likely to be deficient in turf Effects only the foliage applied to, not new growth – Keeps good color without growth

IRON Iron deficiency Chlorosis on new growth High pH soil changes iron to an unusable form

IRON Forms of Iron Iron Sulfate Cheap Short lasting Iron Chelate Expensive Keeps iron in a more useable form Longer impact STABLE!

CEC, Cation Exchange Capacity Nutrient holding potential of soil Cations are positively charged elements Anions negatively charged

CEC, Cation Exchange Capacity Nutrient holding potential Soil particles, particularly clay and OM, have negative charge Soil attracts and holds cations – K, Ca, Mg, NH4

CEC, Cation Exchange Capacity Anions leach through soil – NO3 (nitrate) Almost all N is available as NO3 Sand has low CEC, thus low fertility

Fertilizer

Fertilizer Analysis 3 numbers are % N - P - K (complete fertilizers) – Nitrogen, Phosphorus, and Potassium

Quick Release Nitrogen Water-soluble Immediately available to plant 1 to 2 week supply Frequent, lower rates – Spoon feeding

Quick Nitrogen Release High burn potential Do not apply over 1 pound N / 1000 ft2 Water in after application Susceptible to leaching

Quick Nitrogen Release Inexpensive Urea very common form

Too Much Urea

Slow Release Nitrogen Extended period of time N is released Generally 6 to 10 weeks Quick release N response Slow release N response

Slow Nitrogen Release Not all N in package slow release Less burn potential Less susceptible to leaching

Coated Slow-release Size variation Larger granules Damage affects N release

Sulfur-coated urea (SCU) Urea covered with sulfur and wax MO breaks down the S coating

Sulfur-coated urea (SCU) Imperfect release due to imperfections of coating and damage Least expensive

Polymer-coated Perforated synthetic coating – Osmocote most popular (not for turf) 5 to 16 months release – Coating thickness

Polymer-coated Might be combined with sulfur-coated

Non-coated Slow-release Uniform size Smaller granules Less damage

Nitrogen tied up in complex formaldehyde molecules Dependent on MO to break down Release faster in warmer, wet weather Ureaformaldehyde

Ureaform – Nitroform, UF, Blue Chip products Long complex N-chains Slowest release

Ureaformaldehyde Methylene Ureas – Nutralene products Intermediate N-chains

IBDU Isobutylidene Diurea Water releases nitrogen – Release not as affected by temperature or MO Particle size affects release

Organic Manure, bone meal, sludge MO breaks down Come in very low N% May improve soil over time Very low burn potential

Organic Milorganite, product of Milwaukee Sewage Commission Activated sewage sludge contains 6% N Lower disease and insect

Organic Corn Gluten 10% N Also, pre-emergent herbicide

Applications Use 1/2 rate in heavy shade Use 1/2 rate in heavy shade Turn off at turns Turn off at turns Water immediately Water immediately Avoid spills that burn grass Avoid spills that burn grass

Application Commercial spreader 30’ to 50’

Application Rotary spreader 6’ to 10’

Application Drop spreader – Striping more likely Hand spreader

Applications First Application (Nitrogen): end of April

Applications Last Application: Mid-August with N Sept or Oct apply with P and K

Applications Timing Make applications between 4 to 6 weeks apart depending on fertilizer

Applications Each application 1 pound N / M Bermuda, St. Augustine and zoysia As many as 4 applications per year – May, June, July and August

Applications Each application 1/2 pound N / M Centipede 2 applications per year May and August Centipede: use low P

Fertilizer Label Spreader setting on bag

NITROGEN FERTILIZATION How many pounds of fertilizer has 1 pound of Nitrogen? CALCULATOR ratio has 25% N 100 pounds of fertilizer Has 25 pounds N

NITROGEN FERTILIZATION How many pounds of fertilizer has 1 pound of Nitrogen? 100 DIVIDED BY Nitrogen 100 / 25 = 4 4 pounds of fertilizer ( ) has 1 pound N