Winter Annual and Summer Annual Fertilization Strategies

T. Wade Green

Twiggs County Extension

April, 29, 2008

Basics of Forage Management

Thou Shalt Soil Test

The #1 cause of poor stands at establishment – poor soil fertility or low soil pH.

The First Step

• It’s always better to make fertility recommendations based on a soil sample.

• Phosphorus and Potassium are simply “best guesses” without knowing actual soil levels.

• It doesn’t matter how much fertilizer you dump out there if the pH is 4.5 things are still gonna look terrible.

Winter Annual Forage Systems

Overseeding Winter Annuals into BermudaRyegrass (Annual)RyeOatsWheatTriticale

Arrowleaf Clover

Crimson Clover

Red Clover

Fertilization requirements for winter annual grasses and legumes     Grown Alone1 P3   K4

Winter AnnualAtPlanting Winter

EarlySpring Low Med High   Low Med High

  ----- lbs N/acre ----- --- lbs P2O5/acre --- --- lbs K2O/acre ---

Grasses

Ryegrass 50 50 50 100 50 0 100 50 0

Rye 50 50 - 100 50 0 100 50 0

Wheat 50 50 - 100 50 0 100 50 0

Oats 50 50 - 100 50 0 100 50 0

Triticale 50 50 - 100 50 0 100 50 0

Clovers

Arrowleaf - - - 100 50 0 100 50 0

Ball - - - 100 50 0 100 50 0

Berseem - - - 100 50 0 100 50 0

  Crimson - - - 100 50 0   100 50 0

1 Grown as a single species.3 Phoshorus. Low = soil test levels of 0-30 lbs/A (Coastal Plain) or 0-20 lbs/A (Piedmont); Medium = 31-60

lbs/A (Coast) or 21-40 lbs/A (Pied); High = 61+ lbs/A (Coast) or 41+ lbs/A (Pied).4 K=Potassium. Low = soil test levels of 0-60 lbs/A (Coastal Plain) or 0-100 lbs/A (Piedmont); Medium = 61-150 lbs/A (Coast) or 101-200 lbs/A (Pied); High = 151+ lbs/A (Coast) or 201+ lbs/A (Pied).

Fertilization requirements for winter annual grasses and legumes     Grown in Mixture2 P3   K4

Winter AnnualAtPlanting Winter

EarlySpring Low Med High   Low Med High

  ----- lbs N/acre ----- --- lbs P2O5/acre --- --- lbs K2O/acre ---

Grasses

Ryegrass 50 50 50 100 50 0 100 50 0

Rye 50 50 50 100 50 0 100 50 0

Wheat 50 50 50 100 50 0 100 50 0

Oats 50 50 50 100 50 0 100 50 0

Triticale 50 50 50 100 50 0 100 50 0

Clovers

Arrowleaf 30-50 0-50 - 100 50 0 100 50 0

Ball 30-50 0-50 - 100 50 0 100 50 0

Berseem 30-50 0-50 - 100 50 0 100 50 0

  Crimson 30-50 0-50 - 100 50 0   100 50 0

1 Grown as a single species.

2 Nitrogen (N) is only needed in spring when winter annual grass mixtures include ryegrass. If annual clovers are mixed with annual grasses, apply 30-50 lbs N/acre at planting and 50 lbs N/acre in late winter only if the stand contains less than 40-50% clover.

3 Phoshorus. Low = soil test levels of 0-30 lbs/A (Coastal Plain) or 0-20 lbs/A (Piedmont); Medium = 31-60 lbs/A

(Coast) or 21-40 lbs/A (Pied); High = 61+ lbs/A (Coast) or 41+ lbs/A (Pied).4 K=Potassium. Low = soil test levels of 0-60 lbs/A (Coastal Plain) or 0-100 lbs/A (Piedmont); Medium = 61-150 lbs/A (Coast) or 101-200 lbs/A (Pied); High = 151+ lbs/A (Coast) or 201+ lbs/A (Pied).

Fertilization of Winter and Summer Annual ForagesProduction Distribution of Small Grains Relative to

Annual Ryegrass

0

1000

2000

3000

4000

5000

Janua

ry

Febru

ary

Mar

chApr

ilM

ayJu

neJu

ly

August

Septe

mbe

r

Octob

er

Novem

ber

Decem

ber

Pro

du

cti

on

(lb

s/a

cre

)

Oats

Wheat

Rye

Triticale

Ann. Ryegrass

Summer Annual Forage Systems

• Brown top Millet

• Pearl Millet

• Sorghum Sudan Hybrids

• Others???

Pearl Millet Pennisetum glaucum (others)

• Soil pH 6.0 (can tolerate lower pH)

• 180-240 pounds nitrogen (N) per acre

• Grazing – 40 lbs @ establishment & 50 lbs/month while grazing

• Hay or Silage - 40 lbs @ plant., 60 lbs after establishment and 60 lbs/acre after each cutting

Phosphorus (P3)   Potassium (K4 )

LowCoast: 0-30 lbs/A

Pied: 0-20 lbs/A

MedCoast: 31-60 lbs/A

Pied: 21-40 lbs/A

HighCoast: 61-100 lbs/A

Pied: 41-75 lbs/A  

LowCoast: 0-60 lbs/A

Pied: 0-100 lbs/A

MedCoast: 61-150 lbs/A

Pied: 101-200 lbs/A

HighCoast: 151-250 lbs/A

Pied: 201-350 lbs/A

--- lbs P2O5/acre --- --- lbs K2O/acre ---

60 40 20 100 80 60

*Increase Phosporus and Potassium 25% if more than one cutting anticipated

Sorghum Sudan Grass

• Soil pH 6.0 (not tolerant to acid soils)

• 180-240 pounds nitrogen (N) per acre

• Grazing – 40 lbs @ establishment & 50 lbs/month while grazing

• Hay or Silage - 40 lbs @ plant., 60 lbs after establishment and 60 lbs/acre after each cutting

Phosphorus (P3)   Potassium (K4 )

LowCoast: 0-30 lbs/A

Pied: 0-20 lbs/A

MedCoast: 31-60 lbs/A

Pied: 21-40 lbs/A

HighCoast: 61-100 lbs/A

Pied: 41-75 lbs/A  

LowCoast: 0-60 lbs/A

Pied: 0-100 lbs/A

MedCoast: 61-150 lbs/A

Pied: 101-200 lbs/A

HighCoast: 151-250 lbs/A

Pied: 201-350 lbs/A

--- lbs P2O5/acre --- --- lbs K2O/acre ---

60 40 20 100 80 60

*Increase Phosporus and Potassium 25% if more than one cutting anticipated

Browntop Millet Panicum ramosum

• Soil pH 6.0 • 60 Lbs. N/acre

Phosphorus (P3)   Potassium (K4 )

LowCoast: 0-30 lbs/A

Pied: 0-20 lbs/A

MedCoast: 31-60 lbs/A

Pied: 21-40 lbs/A

HighCoast: 61-100 lbs/A

Pied: 41-75 lbs/A  

LowCoast: 0-60 lbs/A

Pied: 0-100 lbs/A

MedCoast: 61-150 lbs/A

Pied: 101-200 lbs/A

HighCoast: 151-250 lbs/A

Pied: 201-350 lbs/A

--- lbs P2O5/acre --- --- lbs K2O/acre ---

60 40 20 100 80 60

Liebig's Law of the Minimum