Input costs affect overall profitability of cow-calf enterprises Traditionally have been based on N- fertilized warm-season grasses Source: Agricultural.

Improving warm-season pastures using perennial peanut

Kim Mullenix*, Miguel Castillo, and Lynn Sollenberger

Georgia Hay and Forage Conference

Georgia Cattlemen’s Convention

Perry, GA

April 4, 2013

• Input costs affect overall profitability of cow-calf enterprises

• Traditionally have been based on N- fertilized warm-season grasses 2005 2006 2007 2008 2009 2010 2011 2012

0100200300400500600

Figure 1. Ammonium nitrate prices from 2005-2012

Year

Pric

e/to

n ($

)

Source: Agricultural Prices, National Agricultural Statistics Service, USDA, 2013

Introduction

Introduction

• Growing N-fixing legumes with grasses offers an economic opportunity for improving pasture quality, productivity, and animal production in warm-climate regions (Lascano et al., 1989).

• Incorporation of legumes need for N fertilization I pasture nutritive value

Introduction

• Why has warm-season legume use been limited in the Coastal Plain region?

– Historically cheap N fertilizer – Few species options– Challenging to manage– Most not sufficiently grazing tolerant

• Perennial peanut (i.e. Rhizoma peanut)

– Warm-season perennial legume

– Primarily used for hay production

– Adapted to lower southern Coastal Plain region of US

Introduction

Introduction

• Perennial Peanut– Cost of establishment– Time to establish– When planted alone, high

nutritive value may exceed requirements of most beef cattle

Introduction

• Perennial Peanut– Potential for

incorporation into grazing systems

• May spread laterally in grass pastures

– Lower cost strategies are needed for incorporation in beef cattle systems

– Possible approach: strip-planting into grass pastures

What is strip-planting of perennial peanut?

– Increase pasture nutritive value

– Decrease dependence on N fertilizer

– Decrease establishment costs compared to pure RP stands

– Promote formation of long-term grass-legume mixtures

Why strip-planting of perennial peanut?

When and how to strip-plant perennial peanut?

• Selection of “clean” planting area

• Glyphosate application in fall prior to planting

(3 lb a.i./acre)• Disking/tillage prior to

planting• Winter digging of rhizomes

and early spring planting• Planting rate: 80 to 100

bushels/acre

Considerations for strip-planting…

• Can I still use my pasture area during the establishment period?

• What variety of perennial peanut should I plant?

• What weed management strategies will promote mixed legume-grass pasture establishment?

Castillo et al., 2013Defoliation effects during the establishment year

• Key Question– What management

practices should I use during the legume establishment phase so that land is not totally removed from production while allowing successful establishment of the legume?

Castillo et al., 2013Defoliation effects during the establishment year

Treatments

1) Control 2) Hay production

– RP strip and bahiagrass clipped every 28 days

3) Simulated continuous stocking

– Grazed weekly to a 6 inch bahiagrass stubble height

4) Rotational stocking– Grazed every 28 days to a 6

inch bahiagrass stubble height

• Peanut Strip: 13 feet wide x 50 ft long

• Bahiagrass borders: 8 ft wide x 50 ft long

June July August September0

10

20

30

40

50 Control

Hay Production

Simulated Continuous Stocking

Rotational Stocking

Cano

py c

over

(%)

June July August September0

20

40

60

80

100

Samping date

Freq

uenc

y (%

)

Source: Castillo et al., 2013

• Grazing weekly (simulated continuous stocking) or every 28 d (rotational stocking) reduced perennial peanut canopy cover and frequency compared to hay production and the control

Castillo et al., 2013Defoliation effects during the establishment year

Implications

• Longer rest periods between grazing events (i.e. > 28 d) may decrease the negative impact of grazing, but this has not been tested

• If first-year grazing can be successful, it will need to be rotational and cattle will need to be removed based on the height of the forage in the planted strip, not the surrounding grass.

Castillo et al., 2013Defoliation effects during the establishment year

Implications

Considerations for strip-planting…

• Can I still use my pasture area during the establishment period?

• What variety of perennial peanut should I plant?

• What weed management strategies will promote mixed legume-grass pasture establishment?

Florigraze

Intermediate/upright in growth

Developed as dual purpose hay/grazing crop (similar in growth

habit to UF Tito and Peace)

Ecoturf

Decumbent for ornamental or grazing use (similar in growth to

Arblick)

Strip-planting of perennial peanut using different varieties

Key Questions

• Are some perennial peanut varieties able to establish faster and spread more rapidly than others when strip-planted in bahiagrass sod?

• Does defoliation management during the establishment year affect these responses?

Treatments

• Defoliation management – Hay production

• Entire plot mechanically harvested every 28 d to 4 inch bahiagrass stubble height

– Rotational stocking • Grazed every 28 d to a 6 inch bahiagrass stubble height

• Variety– Arblick, Ecoturf: lower-growing– Florigraze, UF Peace: more upright-growing

Strip-planting of perennial peanut using different varieties

Variety Cover (%) Frequency (%)

Arblick 21c 47bc

Ecoturf 28bc 62b

Florigraze 40a 80a

UF Peace 17c 43c

SE 5.7 6.5a,b,c Within a column, means without common superscripts differ (P < 0.05).

2011 ResultsGround cover & frequency

2011 ResultsSpread of perennial peanut into bahiagrass

Arblick Ecoturf Florigraze UF Peace-10

-5

0

5

10

15

20

25

Grazed

Hayed

Spre

ad (i

n)

2012Year-after-establishment

Peanut Spread (ft)

Cover (%)

Frequency(%)

Hayed 3 a 66a 88a

Grazed 2b 46b 87a

a,b Within a column, means without common superscripts differ (P < 0.05).

Implications

• Florigraze and Ecoturf had greater cover, frequency, and spread into bahiagrass during the establishment year compared to other varieties.

• Defoliation during the year of establishment did not affect peanut cover or frequency, but for three of four peanut varieties spread was reduced by grazing vs. cutting for hay.

• Sampling in the year-after-establishment showed decreased cover and spread for grazed vs. hayed treatments.

Considerations for strip-planting…

• Can I still use my pasture area during the establishment period?

• What variety of perennial peanut should I plant?

• What weed management strategies will promote mixed legume-grass pasture establishment?

Castillo et al., in press: Weed Management Study

Treatments

• N levels (0 or 45 lb N per acre)• 6 weed management strategies in planted strip

– Control (no herbicide or mowing)

– Mowing (28 days, 4 inch height)

– Pendimethalin (Prowl; 32 oz/acre at planting)

– Clethodim (Select Max; 12 oz/acre when grass weeds were 4 to 6 in tall)

– Imazapic (Impose; 4 oz/acre; grass/broadleaf were 2 to 4 in)

– Imazapic + 2,4-D (4 oz/acre and 8 oz/acre, respectively; grass/broadleaf were 2 to 4 in)

June July August September0

10

20

30

40

50ControlMowingPendimethalinClethodimImazapicImazapic + 2,4-D

Cano

py c

over

(%)

June July August September0

20

40

60

80

100

Sampling date

Freq

uenc

y (%

)

Source: Castillo et al., in press

Source: Castillo et al., in press

0 lb N acre/year45 lb N/acre/year

Summary of strip-planting research• Can I still use my pasture area

during the establishment period?

• What variety of perennial peanut should I plant?

• What weed management strategies will promote mixed legume/grass pasture establishment?

Hay management promotes more favorable establishment compared with grazing

Florigraze and Ecoturf established more successfully than UF Peace and Arblick

Imazapic or Imazapic + 2,4-D had the most effective control

Challenges and Future Directions

• Remember the goal is to form a long-term mixture.– It will take time and patience to get there.

• There is always room for improvement.– How will strip-planting work with different grasses

(sod-forming vs. bunch types)?• Considerations for GA: Will this work in bermudagrass

pastures?

Challenges and Future Directions

• Other considerations…– Economics of the strip-

planting system– Once a long-term

mixture is formed, what do I need to do to maintain it?

– How much legume do I need in my mixture to replace/reduce my need for N fertilizer?

Thank You!

Questions?