Forage production and persistence characteristics of grazed native warm-season grass mixtures with or without nitrogen fertilizer  

作　　者：Caroline Nicole Chappell Marty Landon Marks Katie Michelle Mason Liliane Severino da Silva Joshua Luke Jacobs Mary Kimberly Mullenix Sandra Leanne Dillard Russell Brian Muntifering 

机构地区：[1]Department of Animal Sciences,Auburn University,Auburn,Alabama,USA [2]Department of Animal Science,University of Tennessee,Knoxville,Tennessee,USA [3]Department of Animal and Veterinary Sciences,Clemson University,Clemson,South Carolina,USA [4]University of Kentucky Cooperative Extension Service,Carlisle,Kentucky,USA

出　　处：《Grassland Research》2022年第3期157-165,共9页草地研究（英文）

摘　　要：Background:Native warm-season grass(NWSG)mixtures may provide a lownitrogen(N)-input summer perennial forage option to extensively managed forage-livestock systems.Methods:Mixed pastures of big bluestem(Andropogon gerardii Vitman),little bluestem(Schizachyrium scoparium Michx.),and indiangrass(Sorghastrum nutans L.)fertilized with 0 or 67 kgNha−1 were continuously stocked with beef heifers and cows.Forage mass,nutritive value,and canopy heights were determined every 2 weeks during the grazing season.Stand persistence measures included the canopy cover and leaf area index(LAI)and plant crown density at spring emergence following 3 years of grazing management.Results:Forage mass,canopy height,and stocking densities were greater for N-fertilized NWSG than unfertilized NWSG for the first 30 days of the growing season across the 3-year study.Forage NWSG fertilized with N had a greater decrease in LAI during the growing season(51%decrease)than unfertilized NWSG.Spring NWSG plant density estimates following 3 years of grazing did not differ across N management strategies.Conclusions:Forage NWSG mixtures supported superior forage attributes and greater stocking densities early in the grazing season under low-level N than zero-N-input systems and may provide a low-N-input alternative for improved species use in southeastern US forage-livestock systems.

关 键 词：continuous stocking GRAZING native warm-season grass mixtures nitrogen fertilization 

分 类 号：S816[农业科学—饲料科学]