Strip-Planting of Rhizoma Peanut In Bahiagrass Pastures to Increase Production and Sustainability of Low-Input Forage-Livestock Systems In Florida.

Nitrogen-limited grasslands degrade, reducing their potential to serve as a source of forage for livestock or provide ecosystem services. Legumes are an alternative to fertilizer N for improving long-term pasture persistence in low-input, forage-livestock systems. Rhizoma peanut (Arachis glabrata Benth.; RP) spreads laterally in grass swards and has demonstrated long-term persistence under grazing, making it an ideal candidate for sustainable pasture systems. Thus far, RP has been used primarily for hay production because of high establishment cost. Alternative low-cost establishment strategies are needed. Research was conducted in Gainesville, FL to evaluate planting of RP in clean-tilled strips in established, low-input bahiagrass (Paspalum notatum Flügge) pastures. Objectives were to identify: 1) the degree to which defoliation management during the establishment period affects presence, cover, and subsequent success of RP; and 2) management options to minimize weed competition with RP for nutrients and light. During the establishment year, continuous and rotational stocking severely reduced RP cover (3 and 5%, respectively) and frequency (21 and 26%, respectively) compared to treatments where the bahiagrass pasture was managed for hay production (17% cover and 50% frequency). The use of imazapic and imazapic + 2,4-D in strips planted to RP greatly reduced weed competition and allowed greater RP cover and frequency (22 and 23% cover, 50 and 52% frequency, for imazapic and imazapic + 2,4-D, respectively) compared to an untreated control (3 and 22%), frequent mowing (2 and 14%), and application of clethodim (6 and 26%) or pendimethalin (4 and 20%) herbicides. Application of 50 kg N ha^-1 following herbicide treatment resulted in greater RP cover and frequency in treatments where weeds were controlled successfully. Data show that strip planting RP in bahiagrass is a viable option, but defoliation and weed management are critical to RP establishment success.