Forage Characteristics of Bermudagrass Pastures Mixed with Pintoi Peanut and Grazed at Different Stubble Heights.

Pintoi peanut (Arachis pintoi Krap. and Greg.) is a productive perennial warm-season legume in tropical regions; however, there is limited information about its performance when mixed with bermudagrass [Cynodon dactylon (L.) Pers. Schreb.] in subtropical regions. The objective of this study was to investigate the effects of overseeding ‘Amarillo’ pintoi peanut into ‘Jiggs’ bermudagrass pastures grazed at different stubble heights. The experiment was conducted in Ona, FL from June to October 2014. Treatments were the split-plot arrangement of bermudagrass monoculture or bermudagrass overseeded with pintoi peanut (main plots) and grazed at 15- or 30-cm stubble height (sub-plot; SH15 and SH30, respectively) distributed in a completely randomized design with four replicates. Established bermudagrass pastures (2500 m²) were overseeded with 10 kg ha^-1 of pintoi peanut in 2013. Pastures were mob stocked with 28-d resting periods between grazing events. There was no effect of pintoi peanut overseeding on herbage accumulation rate (HAR, mean = 30 kg ha^-1 d^-1), crude protein (CP; mean = 99 g kg^-1), or in vitro digestible organic matter (IVDOM; mean = 393 g kg^-1). There was a stocking rate x month interaction for these response variables. From July through October, forage CP (from 101 to 81 g kg^-1) and IVDOM (from 400 to 330 g kg^-1) decreased for SH30; however, SH15 maintained similar nutritive value during the experimental period. The HAR decreased from 83 to 16 kg ha^-1 d^-1 and 36 to -6 kg ha^-1 d^-1 for the SH15 and SH30 treatments, respectively, from July to October. Proportion of pintoi peanut in the herbage mass (mean = 1.6%) and frequency (mean = 5 plants m^-2) were not affected by stubble height. Pintoi peanut was persistent under different stubble heights; however, it did not increase forage nutritive value and accumulation due to limited contribution in the herbage mass.