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Transcript of Input costs affect overall profitability of cow-calf enterprises Traditionally have been based on N-...
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
– 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
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?