Input costs affect overall profitability of cow-calf enterprises Traditionally have been based on N- fertilized warm-season grasses Source: Agricultural Prices, National Agricultural Statistics Service, USDA, 2013

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

limited 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

Perennial Peanut – Cost of establishment – Time to establish – When planted alone, high nutritive value may exceed requirements of most beef cattle

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 Why strip-planting of perennial peanut?

Whenhow 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?

Defoliation effects during the establishment year Castillo et al., 2013 Defoliation 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., 2013 Defoliation 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 Peanut Strip: 13 feet wide x 50 ft long Bahiagrass borders: 8 ft wide x 50 ft long

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

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

VarietyCover (%)Frequency (%) Arblick21 c 47 bc Ecoturf28 bc 62 b Florigraze40 a 80 a UF Peace17 c 43 c SE a,b,c Within a column, means without common superscripts differ (P < 0.05).

2012 Year-after-establishment Peanut Spread (ft) Cover (%) Frequency (%) Hayed 3 a3 a 66 a 88 a Grazed 2b2b 46 b 87 a 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?

Weed Management Study 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 –Control (no herbicide or mowing) –Mowing –Mowing (28 days, 4 inch height) –Pendimethalin –Pendimethalin (Prowl; 32 oz/acre at planting) –Clethodim –Clethodim (Select Max; 12 oz/acre when grass weeds were 4 to 6 in tall) –Imazapic –Imazapic (Impose; 4 oz/acre; grass/broadleaf were 2 to 4 in) –Imazapic + 2,4-D –Imazapic + 2,4-D (4 oz/acre and 8 oz/acre, respectively; grass/broadleaf were 2 to 4 in)

Source: Castillo et al., in press

0 lb N acre/year 45 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?