Belowground Responses from Annual and Perennial Peanuts Mixed with ‘Pensacola’ Bahiagrass.

Root and rhizomes are important C allocation structures in grassland ecosystems, thus it is important to understand root-rhizome responses in grass-legume mixted systems. In this study, we evaluated belowground responses when ‘Pensacola’ bahiagrass (Paspalum notatum Flugge) was mixed with four different Arachis spp. Treatments consisted of bahiagrass mixtures with: 1) A. glabrata cv. Florigraze; 2) A. glabrata germplasm Ecoturf; 3) A. pintoi cv. Amarillo; 4) A. hypogea cv. TUFRunner 727; and 5) bahiagrass monoculture without N fertilizer. Treatments were allocated in a randomized complete block design, with four replications. Two root-rhizome cores per plot were obtained using a 20 x 10.8 cm golf-hole cutter on November of each year. Root-rhizome mass increased from 2015 to 2016, with ecoturf-bahiagrass mixtures having the greatest magnitude in increasing in root-rhizome mass in both years, indicating it was the most well-established mixture. In addition, ecoturf-bahiagrass mixtures showed the greatest overall increase in their N pool from 41 to 115 kg N ha^-1, from 2015 to 2016. Amarillo-bahiagrass mixtures had the lowest root-rhizoma mass in both years, indicating loss of stand of the peanut plant material. Overall, A. glabrata species, specifically Ecoturf, tended to outperform all other peanut species planted into bahiagrass pastures.