Land-Preparation Techniques and Weed-Competition Control Strategies for Successful Establishment of Strip-Planted Rhizoma Peanut in Bahiagrass Pastures.

Rhizoma peanut (Arachis glabrata Benth.; RP) is a warm-season perennial legume that spreads laterally and has demonstrated long-term persistence under grazing, making it an ideal candidate for sustainable forage-livestock systems in the southeastern USA. In spite of its obvious potential as a companion to grasses in pasture, high cost of vegetative propagation, and management of weeds and water have limited its use to high cash value hay production systems. Research is needed to develop novel approaches for overcoming barriers to successful RP-grass associations and to identify low-cost, long-term solutions to the problem of N limitation in low-input systems. Research was conducted in Gainesville, FL to evaluate what combinations of seedbed preparation and post-plant competition-control strategies are most effective for RP establishment in strips in bahiagrass (Paspalum notatum Flügge) pastures. The objectives were to: 1) quantify the effect of seedbed preparation techniques on RP cover, frequency, and spread; and 2) quantify the effect of post-plant competition control strategies and their interactions with seedbed preparation techniques to minimize competition for nutrients and light. Canopy cover and frequency were similar in Conventional tillage (16%), No-till (16%), and Sod-lifting (14%) land preparation techniques. The application of imazapic or imazapic + 2,4-D in strips planted to RP greatly reduced weed competition and allowed greater RP cover and frequency (20 and 21% cover, 46 and 38% frequency, respectively) compared to an untreated control (11 and 35%) and frequent mowing (6 and 27%). Spread of RP into the bahiagrass sod was 20 and 9 cm greater for Conventional tillage and No-till, respectively, compared to Sod-lifting. Data show that a single application of glyphosate to kill the grass in the strips followed by No-till planting of RP and the post-emergence use of imazapic is a viable option for successful establishment of RP in strips in bahiagrass pastures.