GIVE

Dr. Jose Dubeux

Research

The overall goal of our research program is to evaluate strategies to reduce off-farm inputs and to increase sustainability of forage production systems in Florida. A primary goal will be to reduce the dependence of cattle production systems on N fertilizer, a major source of GHG emission. We will address the reduction on N fertilization by evaluating the potential of year-round cattle production systems based on grass-legume mixtures. Reduction in off-farm inputs such as fossil fuels used in bailing operations will also be targeted by evaluating alternative options for feeding cattle during the period of forage shortage, such as cool-season pastures and stockpiled forage. Carbon footprint from rangelands, hayfields, improved warm-season and cool-season pastures will be assessed by measuring greenhouse gas (GHG) emissions and soil C stocks. After assessing, strategies will be set in order to reduce GHG emissions from each particular system. Specific objectives of the program are:

  • To evaluate warm-season and cool-season grass/legume mixtures in multiple locations, identifying the best grass/legume combinations, the N fixation potential of the evaluated legumes, strategies of establishment of perennial legumes on warm-season perennial grass pastures, and reseeding potential of cool-season legumes.
  • To evaluate forage production system measuring animal performance, pasture characteristics, nutrient cycling on legume based systems vs. grass fertilized systems, and assessment of carbon footprint (CO2, CH4, and N2O) and soil C stock of forage production systems in Florida including rangelands, hay fields, bahiagrass pastures, and cool-season pastures.
  • To evaluate strategies to reduce cattle feeding cost by increasing grazing length using cool-season forages based on small grain/annual ryegrass pastures and by assessing the potential of using stockpiled forages in North Florida.
  • To develop educational program and decision support tools directed towards the extension faculties, producers, policy makers, and allied industry audience to increase awareness of potential cattle production systems for different regions of Florida and to increase legume adoption.

Products/Outputs
  • Peer-reviewed publications are one of the main expected outcomes of this program, advancing the knowledge on grass/legume mixtures across different Florida environments.
  • Identification of a year-round cattle production system with no need of N fertilizer application.
  • Seed rate recommendation to optimize reseeding potential of cool-season legumes established onto perennial warm-season grass.
  • Preliminary data on nutrient cycling of grass in monoculture or mixed with legumes will be used as an input to a nutrient cycling model with the goal of estimating herbage growth, animal output, and the need of fertilizer application.
  • Determine the N input from legume in grass-legume mixture and compare its economics with N fertilizer.
  • Recommendation of establishment methods for perennial peanut on bahiagrass pastures.
  • Identification of cattle production systems with high/low carbon footprint will give preliminary data and inputs to the research program in order to plan future research trying to reduce current GHG emissions of high carbon footprint systems.
  • Recommendation of a limpograss cultivar for use as stockpiled forage in North Florida.
  • Extension publications based on the scientific results obtained in the project. These extension publications will be producer oriented, using proper extension outlets.
  • Development of a decision tree system to support extension faculties and producers on how to make decisions regarding pasture management practices and forage feeding options.

Expected outcomes
  • Legume-based systems will likely have lower carbon footprint, reducing GHG emissions, and increasing opportunity to market products with a higher price.
  • Assessment of current GHG emissions from different forage production systems will create an opportunity to address systems with higher carbon footprint and to evaluate new management practices trying to reduce emissions.
  • Increase adoption by producers of grass-legume mixtures on pastures in the southern coastal plain of SE USA.
  • Reduce off-farm inputs on feeding operations during the forage shortage periods, increasing producer profitability and reducing GHG emissions.

Assistant Professor — Forage Management