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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Environmentally Integrated Dairy Management Research » Research » Publications at this Location » Publication #420981
Research Project: Innovative Forage and Pasture Management Strategies for Dairy Agroecosystems

Location: Environmentally Integrated Dairy Management Research

Title: Rhizoma peanut root-rhizome mass, growth, and decomposition under grazing or clipping management

Author
item SANTOS, ERICK - University Of Alberta
item DUBEUX, JOSE - University Of Florida
item SOLLENBERGER, LYNN - University Of Florida
item MACKOWIAK, CHERYL - University Of Florida
item Jaramillo, David
item VAN CLEFF, FLAVIA - University Of Florida
item QUEIROZ, LUANA - University Of Florida
item GARCIA, LIZA - University Of Florida
item SIQUEIRA, MICHELLE - Federal Rural University Of Pernambuco
item ZAGATO, LUANA - Clemson University
item GARCIA, CARLOS - Clemson University
item LOGHINI, VANESSA - University Of Florida
item HOMEM, BRUNO - University Of Florida

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/26/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Roots are important contributors to nutrient cycling in grassland ecosystems. However, few studies have evaluated the belowground dynamics of warm-season perennial forages under different management practices. Root and rhizome biomass is an essential nitrogen source in grasslands and understanding their growth dynamics is helpful for informing management practices that promote nitrogen cycling in grasslands. This study evaluated root and rhizome responses, and decomposition dynamics of a perennial legume rhizoma peanut, under continuous stocking or 56-day clipping intervals, simulating hay production, across three 56-day periods in 2018 and 2019. In 2019, root-rhizome production was greater under clipping than grazing in two out of three periods. The decay rates and nitrogen return rates from roots and rhizomes were influenced by rainfall, with greatest decay rates observed during the wetter year. Overall, this study showed that pastures where rhizoma peanut covers 30% of the area, root and rhizomes contribute an estimated return of 12 to 21 kg N/ha per season.

Technical Abstract: Belowground plant structures are integral contributors to nutrient cycling in grassland ecosystems. However, relative to herbage responses, few studies have examined the belowground dynamics of warm-season perennial forages under different management practices. This study evaluated root-rhizome responses and decomposition dynamics of a perennial legume [rhizoma peanut (RP; Arachis glabrata Benth.)] under continuous stocking (grazing) and 56-day clipping (haying) intervals across three 56-day periods in 2018 and 2019. In 2019, root-rhizome mass was greater under haying than grazing in two out of three periods, peaking at 14980 kg OM/ha. Conversely, root-rhizome N concentration was lower with haying than grazing (12 vs. 14 g /kg). Root-rhizome growth rate was higher in 2018 than 2019 (18.0 vs. 10.5 kg OM/ha/d). In 2019, grazed plots exhibited higher biomass (0.0013 vs. 0.0010 g/g/d) and N decay rates (0.0016 vs. 0.0011 g/g/d) than hayed plots. Root-rhizome N pools for 2018 and 2019 averaged 159 and 192 kg N/ha, with 86% and 93% N remaining post-incubation, respectively. With RP covering 30% of the pasture, root-rhizomes contribute an estimated 12–21 kg N/ha per season. Root-rhizome dynamics in RP were influenced by defoliation management, though responses varied between years.